CN114605050A

CN114605050A - Sewage sludge combined treatment system and method based on biological predation synchronous sludge reduction and phosphorus recovery

Info

Publication number: CN114605050A
Application number: CN202210404691.6A
Authority: CN
Inventors: 田禹; 陈俊杰; 李俐频; 詹巍
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2022-04-18
Filing date: 2022-04-18
Publication date: 2022-06-10

Abstract

The invention discloses a sewage and sludge combined treatment system and a treatment method based on biological predation synchronous sludge reduction and phosphorus recovery, which relate to the fields of sewage and sludge treatment by using biotechnology and phosphorus resource recovery, and aim to solve the problems of high sludge yield, high sludge treatment energy consumption and easy generation of secondary pollution in the traditional activated sludge process sewage treatment technology; the prior synchronous sewage and sludge treatment technology has the problems of low phosphorus resource recovery efficiency, difficult stable effluent quality reaching the standard and the like. According to the invention, by researching and developing a novel enhanced sludge decrement reactor with a special structure and a control mode, worm predation and microbial synergistic action are established, synchronous sludge decrement and enhanced phosphorus release are realized, a phosphorus-rich sludge supernatant is obtained, favorable conditions are created for sidestream phosphorus recovery, and efficient sewage treatment, efficient sludge decrement and synchronous phosphorus resource recovery are realized by combined operation of the novel enhanced sludge decrement reactor and a phosphate precipitation method phosphorus recovery device and an activated sludge method biological sewage treatment device. The invention is applied to the field of sewage and sludge treatment.

Description

Sewage sludge combined treatment system and method based on biological predation synchronous sludge reduction and phosphorus recovery

Technical Field

The invention belongs to the field of sludge treatment by using biotechnology and sewage phosphorus resource recovery, and particularly relates to a sewage and sludge combined treatment system and a treatment method based on biological predation synchronous sludge reduction and phosphorus recovery.

Background

The activated sludge process has become one of the most widely used sewage treatment technologies worldwide, and a large amount of excess sludge by-products is one of the major weaknesses of the activated sludge process. With the rise of sewage treatment rate and the improvement of environmental protection requirements, the problem of sludge treatment and disposal is increasingly prominent, and the annual sludge production of China in 2025 is expected to break through 9000 ten thousand tons (calculated by water content of 80%). The conventional sludge treatment technology adopted by the current sewage treatment plant is expensive, and accounts for about 50-60% of the total operation cost of the sewage treatment plant. Therefore, in order to reduce the transportation and subsequent treatment costs, the sludge in-situ reduction technology attracts much attention, namely the yield of the excess sludge is reduced to the maximum extent from the source, and the sludge in-situ reduction technologies generally accepted at home and abroad at present are divided into lysis-recessive growth, endogenous respiration, uncoupling metabolism and biological predation. The biological predatory sludge reduction technology is based on the principle that energy and substances are gradually reduced in the ecological food chain transfer process, and compared with the former three technologies, the biological predatory sludge reduction technology has the reduction mechanism of 'pure ecology, low energy consumption and no secondary pollution', lower treatment cost and better reduction effect, so that the biological predatory sludge reduction technology is more and more emphasized.

Phosphorus is a main factor causing water eutrophication, and the water is considered as the eutrophicated water when the total phosphorus concentration in the water exceeds 0.02 mg/L. In addition, phosphorus is an important non-renewable resource, and the phosphorite in China is expected to become a shortage resource after 2050 years. A large number of research results show that 90-95% of total phosphorus in raw water is transferred and enriched in sewage sludge in the sewage treatment process by an activated sludge method. The method for recovering the phosphorus resource from the sewage sludge can solve the problem of water eutrophication caused by overhigh phosphorus content in the water, relieve the shortage of the phosphorus resource and realize the recycling economy of resource recovery, so the method for recovering the phosphorus resource from the sewage sludge has great potential and application prospect. The technology for recovering phosphorus from sludge includes adsorption and desorption method, biological strengthening method, phosphate precipitation method, etc. Among them, the phosphate precipitation method has the advantages of simple operation, high phosphorus recovery efficiency, stable treatment effect, no secondary phosphorus release pollution, strong impact load resistance and the like, and is widely researched and applied.

Based on the research of the early stage of biological predation, the synchronous nitrification and denitrification phosphorus removal effects are generated in the worm predation process under certain conditions, and meanwhile, when the boundary conditions of denitrification phosphorus removal disappear, the sludge in the system gradually generates the anaerobic phosphorus release effect. Based on the above, the invention provides the biological predation sludge reduction device for realizing the efficient sludge reduction and the enhanced phosphorus release based on the synergistic effect of worms and microorganisms, the microorganisms are not only objects predated by worms but also are players of substance migration and transformation, the carbon nitrogen removal and the enhanced phosphorus release are realized simultaneously in the sludge reduction, and the higher phosphorus concentration in the sludge supernatant liquid enables the side flow reactor to realize the phosphorus recovery. Therefore, by researching and developing a sludge reduction device with a special structure and a special control mode and establishing a phosphorus recovery side-stream process based on an enhanced sludge reduction and phosphate precipitation method, the problem of low phosphorus release efficiency of an anaerobic tank in the traditional side-stream phosphorus recovery can be effectively solved, a new solution is provided for synchronous efficient stable treatment and resource recovery of sewage and sludge, and the method has great social requirements. The 'sludge reduction and denitrification coupled municipal sewage sludge combined treatment system' with the publication number of 101786779 discloses a biological predatory sludge reduction and denitrification municipal sewage sludge treatment system, but the treatment system mainly removes carbon and nitrogen pollutants in supernate and does not have the functions of strengthening phosphorus release and resource recovery.

Disclosure of Invention

The invention aims to provide a sewage and sludge combined treatment system and a treatment method based on synchronous sludge decrement and phosphorus recovery of biological predation, and aims to solve the problems that the conventional activated sludge process sewage treatment technology is high in sludge yield, high in sludge treatment energy consumption and easy to generate secondary pollution, and the existing sewage and sludge synchronous treatment technology is low in phosphorus resource recovery efficiency and difficult in stable effluent quality reaching the standard.

In order to solve the above technical problems, a first technical solution of the present invention is: the sewage and sludge combined treatment system with the coupling of sludge reduction and phosphorus recovery consists of an activated sludge process biological sewage treatment device, a second regulating valve, a first sludge pump, a sludge reduction device, a fifth regulating valve, a second sludge pump, a third regulating valve, a first sewage pump, a phosphate precipitation process phosphorus recovery device, a fourth regulating valve and a second sewage pump;

the activated sludge process biological sewage treatment device consists of an activated sludge process bioreactor, a first water inlet pipe, a first sludge inlet pipe and a first sludge discharge pipe;

the sludge reduction device consists of a sludge reduction reactor, a separation net, a porous suspended spherical filler, a water quality multi-parameter online monitor, a second aeration device, a second sludge inlet pipe, a second sludge discharge pipe and a first sludge discharge pipe; the sludge reduction reactor consists of a worm predation and enhanced phosphorus release area, a baffle plate and a mud-water separation and precipitation area; the second aeration equipment is a variable aeration device and consists of a second time relay, a second lead, a second air compressor, a second air inlet pipe, an automatic gas flow regulator and a variable microporous aeration pipe; the porous suspension spherical filler consists of a spherical shell, a filler layer filled in the spherical shell and fillers which are woven outside the spherical shell in a crossed manner;

the phosphate precipitation method phosphorus recovery device consists of a phosphate precipitation method phosphorus recovery reactor, a mechanical stirrer, a second water inlet pipe and a second water discharge pipe;

the first water inlet pipe is communicated with the side wall of the upper end of the activated sludge process bioreactor, the first sludge inlet pipe is communicated with the side wall of the lower end of the activated sludge process bioreactor, and the first sludge discharge pipe is communicated with the bottom wall of the activated sludge process bioreactor;

the second sludge inlet pipe is communicated with the side wall at the lower end of the worm predation and enhanced phosphorus release area of the sludge reduction reactor, the worm predation and enhanced phosphorus release area is communicated with the mud-water separation and precipitation area through an overflow weir at the upper end of a side wall, the mud-water separation and precipitation area is divided into two parts by a baffle, the second sludge discharge pipe is communicated with a sludge hopper at the lower end of the mud-water separation and precipitation area, the first water discharge pipe is communicated with the side wall at the upper end of the mud-water separation and precipitation area, the water quality multi-parameter online monitor is arranged at the middle upper part in the worm predation and enhanced phosphorus release area and is used for online measuring the pH, the temperature and the dissolved oxygen water quality indexes in real time, the partition nets are movably arranged at intervals in the worm predation and enhanced phosphorus release area, the porous suspension spherical filler is arranged between the two partition nets, a plurality of variable air outlet holes are uniformly distributed on the inner wall of the variable microporous aeration pipe, and the aperture diameter is in a variable range of 0.2-0.8 mm, the variable microporous aeration pipe is arranged below a lowermost separation net in the worm predation and intensified phosphorus release region in a shape like a Chinese character 'mu', the variable microporous aeration pipe is communicated with a second air compressor outside the worm predation and intensified phosphorus release region through a second air inlet pipe, the automatic gas flow regulator is arranged on the second air inlet pipe and is communicated with the water quality multi-parameter online monitor through an automatic control system, after the automatic gas flow regulator is arranged, the air flow entering the variable microporous aeration pipes can be automatically regulated according to the dissolved oxygen concentration of sludge-water mixed liquid in the worm predation and intensified phosphorus release region, so that variable aeration is realized, and the second time relay is connected with the second air compressor through a second lead;

the mechanical stirrer is arranged in the phosphate precipitation method phosphorus recovery reactor, the second water inlet pipe is communicated with the side wall of the upper end of the phosphate precipitation method phosphorus recovery reactor, and the second water outlet pipe is communicated with the side wall of the lower end of the phosphate precipitation method phosphorus recovery reactor;

the first sludge discharge pipe is communicated with the second sludge inlet pipe, and a first sludge discharge pump is arranged between the first sludge discharge pipe and the second sludge inlet pipe; the first sludge inlet pipe is communicated with the second sludge discharge pipe, and a second sludge discharge pump is arranged between the first sludge inlet pipe and the second sludge discharge pipe; the first drainage pipe is communicated with the second water inlet pipe, and a first sewage pump is arranged between the first drainage pipe and the second water inlet pipe; the second water discharge pipe is communicated with the first water inlet pipe, and a second sewage pump is arranged between the second water discharge pipe and the first water inlet pipe; no. two governing valves are installed on first mud pipe, No. five governing valves are installed on second mud pipe, No. three governing valves are installed on first drain pipe, No. four governing valves are installed on the second drain pipe.

Furthermore, the outer spherical shell is made of polyurethane or high-density polyethylene and has the size of 6cm multiplied by 6 cm-10 cm multiplied by 10cm, the shell is provided with latticed openings, and the spherical shell is formed by combining an upper shell and a lower shell in an inner buckle way; a plurality of S-shaped bent holes (shown in figure 3) with the width of 2-3 mm are uniformly distributed in the packing layer, and the S-shaped bent holes are vertically and horizontally staggered and communicated with each other.

Further, the activated sludge process biological sewage treatment device is a sequencing batch activated sludge process biological sewage treatment device, an oxidation ditch activated sludge process biological sewage treatment device, A²One or more of an O activated sludge process biological sewage treatment device and an MBR activated sludge process biological sewage treatment device.

The method for treating sewage sludge by adopting the sewage sludge combined treatment system based on biological predation synchronous sludge reduction and phosphorus recovery is carried out according to the following steps:

when the system starts to operate, sewage to be treated is injected into the activated sludge bioreactor through the first water inlet pipe for treatment, the treated sewage sludge is led into the sludge reduction device for treatment through the first sludge discharge pump, sludge-water mixed liquid treated by worm predation and enhanced phosphorus release areas is discharged into the sludge-water separation and precipitation area, and the sludge precipitated in the sludge-water separation and precipitation area is pumped into the activated sludge bioreactor through the second sludge discharge pump; then directly discharging the sludge supernatant obtained by the treatment of the sludge-water separation and precipitation zone into a phosphate precipitation method phosphorus recovery reactor through a first sewage pump for phosphorus resource recovery; the recovered sludge supernatant is pumped into an activated sludge process bioreactor through a second sewage pump (to be operated in the next period;

wherein, during the period from one cycle of the operation of the sewage sludge combined treatment system to the end of the operation of the system: before the operation period of an activated sludge process biological sewage treatment device is finished, the activated sludge in the activated sludge process biological sewage treatment device is discharged into a worm predation and enhanced phosphorus release area through a sludge discharge pump at the flow rate of 5-20 percent of the water inlet flow rate of the activated sludge process biological sewage treatment device; before the activated sludge is discharged into a worm predation and enhanced phosphorus release area, firstly, the precipitated sludge in a sludge-water separation and precipitation area in a sludge reduction device is discharged into an activated sludge method biological sewage treatment device through a second sludge discharge pump at the flow rate of 2-7% of the inflow water of the activated sludge method biological sewage treatment device, and the sludge supernatant is discharged into a phosphate precipitation method phosphorus recovery reactor at the flow rate of 3-13% of the inflow water of the activated sludge method biological sewage treatment device; before a sludge-water mixed liquid in a sludge-water separation and precipitation area in a sludge reduction device is injected into an activated sludge method biological sewage treatment device and a phosphate precipitation method phosphorus recovery reactor, sludge supernatant liquid after precipitation treatment in the phosphate precipitation method phosphorus recovery reactor is mixed with inlet water of the activated sludge method biological sewage treatment device through a second sewage pump and enters the activated sludge method biological sewage treatment device;

during the operation of the sewage sludge combined treatment system, monitoring the water quality of worm predation and intensified phosphorus release areas by using a water quality multi-parameter online monitor;

the DO concentration in the enhanced phosphorus release zone is maintained at 0.5-1.0 mg/L, the temperature is 20-35 ℃, and the pH is 6.5-9.

Further, the filler is in a fiber filament shape and is made of modified hydrophilic polypropylene or high-density polyethylene material.

Further, the phosphorus recovery method of the phosphate precipitation method phosphorus recovery reactor is any one of hydroxyapatite, aluminum phosphate, iron phosphate, vivianite or struvite (MAP) phosphate precipitation method.

The second scheme of the invention is as follows: a sewage sludge combined treatment system based on biological predation synchronous sludge reduction and phosphorus recovery comprises an activated sludge process biological sewage treatment device, a second regulating valve, a first sludge pump, a sludge reduction device, a fifth regulating valve, a second sludge pump, a third regulating valve, a first sewage pump, a phosphate precipitation process phosphorus recovery device, a fourth regulating valve and a second sewage pump; the activated sludge process biological sewage treatment device is a sequencing batch activated sludge process biological sewage treatment device;

the sequencing batch activated sludge process biological sewage treatment device consists of a sequencing batch activated sludge process bioreactor, a first water inlet pipe, a first sludge discharge pipe and first aeration equipment; the first aeration equipment consists of an aeration head, a first regulating valve, a first air inlet pipe, a first air compressor, a first lead and a first time relay;

the first water inlet pipe is communicated with the upper part of the sequencing batch activated sludge process bioreactor, the first sludge inlet pipe is communicated with the lower part of the sequencing batch activated sludge process bioreactor, the first sludge discharge pipe is communicated with the bottom of the sequencing batch activated sludge process bioreactor, the aeration head is arranged at the bottom in the sequencing batch activated sludge process bioreactor, the air inlet of the aeration head is communicated with the air outlet of a first air compressor outside the sequencing batch activated sludge process bioreactor through a first air inlet pipe, the first regulating valve is arranged on the first air inlet pipe, and the first time relay is connected with the first air compressor through a first lead;

the second sludge inlet pipe is communicated with the lower part of the worm predation and enhanced phosphorus release area, the worm predation and enhanced phosphorus release area is communicated with the mud-water separation and precipitation area through an overflow weir at the upper end of a side wall, the mud-water separation and precipitation area is divided into two parts by a baffle, the second sludge discharge pipe is communicated with a sludge hopper at the bottom of the mud-water separation and precipitation area, the first water discharge pipe is communicated with the upper part of the mud-water separation and precipitation area, the water quality multi-parameter online monitor is arranged at the middle upper part in the worm predation and enhanced phosphorus release area, the partition nets are movably arranged in the worm predation and enhanced phosphorus release area at equal intervals, the porous suspension spherical filler is arranged between two adjacent partition nets, a plurality of variable air outlet holes are uniformly distributed on the variable micropore aeration pipe, the aperture diameter variable range is 0.2-0.8 mm, and the porous suspension spherical filler is arranged at the bottom in the worm predation and enhanced phosphorus release area in a 'mesh' shape, the variable micropore aeration pipe is communicated with a second air compressor outside the worm predation and intensified phosphorus release area through a second air inlet pipe, the automatic gas flow regulator is installed on the second air inlet pipe and is communicated with the water quality multi-parameter online monitor through an automatic control system, and the second time relay is connected with the second air compressor through a second lead;

the mechanical stirrer is arranged in the phosphate precipitation method phosphorus recovery reactor, the second water inlet pipe is communicated with the upper part of the phosphate precipitation method phosphorus recovery reactor, and the second water discharge pipe is communicated with the lower part of the phosphate precipitation method phosphorus recovery reactor;

the first sludge discharge pipe is communicated with the second sludge inlet pipe, and a first sludge discharge pump is arranged between the first sludge discharge pipe and the second sludge inlet pipe;

the first sludge inlet pipe is communicated with the second sludge discharge pipe, and a second sludge discharge pump is arranged between the first sludge inlet pipe and the second sludge discharge pipe; the first drainage pipe is communicated with the second water inlet pipe, and a first sewage pump is arranged between the first drainage pipe and the second water inlet pipe; the second water discharge pipe is communicated with the first water inlet pipe, and a second sewage pump is arranged between the second water discharge pipe and the first water inlet pipe; no. two governing valves are installed on first mud pipe, No. five governing valves are installed on second mud pipe, No. three governing valves are installed on first drain pipe, No. four governing valves are installed on the second drain pipe.

The method for treating the municipal sewage sludge by adopting the sewage sludge combined treatment system based on the synchronous sludge decrement and phosphorus recovery of the biological predation is carried out according to the following steps:

when the system starts to operate, the urban sewage to be treated is injected into the sequencing batch activated sludge process bioreactor through the first water inlet pipe for treatment, the treated sewage sludge is led into the sludge reduction device for treatment through the first sludge discharge pump, the sludge-water mixed liquid treated by the worm predation and enhanced phosphorus release areas is discharged into the sludge-water separation and precipitation area, and the sludge precipitated by the sludge-water separation and precipitation area is pumped into the sequencing batch activated sludge process bioreactor through the second sludge discharge pump; then directly discharging the sludge supernatant obtained by the treatment of the sludge-water separation and precipitation zone into a phosphate precipitation method phosphorus recovery reactor through a first sewage pump for phosphorus resource recovery; pumping the recovered sludge supernatant into a sequencing batch activated sludge process bioreactor through a second sewage pump, and carrying out the next cycle operation;

wherein, during the period from one cycle of the operation of the municipal sewage sludge combined treatment system to the end of the operation of the system: before the operation cycle of a sequencing batch activated sludge process biological sewage treatment device is finished, discharging activated sludge in the sequencing batch activated sludge process biological sewage treatment device into a worm predation and enhanced phosphorus release region through a sludge discharge pump at a flow rate which is 5-20% of the water inlet flow rate of the sequencing batch activated sludge process biological sewage treatment device; before the activated sludge is discharged into a worm predation and enhanced phosphorus release region, firstly discharging the precipitated sludge in a mud-water separation and precipitation region in a sludge reduction device into a sequencing batch activated sludge process biological sewage treatment device through a second sludge discharge pump at a flow rate of 2-7% of the water inlet flow rate of the sequencing batch activated sludge process biological sewage treatment device, and discharging the sludge supernatant into a phosphate precipitation process phosphorus recovery reactor at a flow rate of 3-13% of the water inlet flow rate of the sequencing batch activated sludge process biological sewage treatment device; before a sludge-water mixed liquid in a sludge-water separation and precipitation area in a sludge reduction device is injected into a sequencing batch activated sludge process biological sewage treatment device and a phosphate precipitation process phosphorus recovery reactor, sludge supernatant liquid after precipitation treatment in the phosphate precipitation process phosphorus recovery reactor is mixed with inlet water of the sequencing batch activated sludge process biological sewage treatment device through a second sewage pump and enters the sequencing batch activated sludge process biological sewage treatment device;

during the operation of the municipal sewage sludge combined treatment system, monitoring the water quality of worm predation and intensified phosphorus release areas by using a water quality multi-parameter online monitor;

the DO concentration in the enhanced phosphorus release zone is maintained at 0.5-1.0 mg/L, the temperature is 23 +/-2 ℃, and the pH value is 6.5-9;

the operation period of the sequencing batch activated sludge process biological sewage treatment device is 6-10 hours, the water inflow time is 0.5-1.0 hour, the aeration time is 4-6 hours, the sedimentation time is 1-2 hours, the water drainage time is 0.5-1.0 hour, 2-4 operation periods are carried out in one day, the dissolved oxygen is controlled to be 3-4 mg/L, and the sludge concentration is maintained to be 3000-4000 mg/L; and in the operation process of the sludge reduction device, the hydraulic retention time is 10-12 h.

The third technical scheme of the invention is as follows: a sewage sludge combined treatment system based on biological predation synchronous sludge reduction and phosphorus recovery is composed of an MBR (membrane bioreactor) activated sludge process biological sewage treatment device, a second regulating valve, a first sludge discharge pump, a sludge reduction device, a fifth regulating valve, a second sludge discharge pump, a third regulating valve, a first sewage pump, a phosphate precipitation process phosphorus recovery device, a fourth regulating valve and a second sewage pump;

the MBR activated sludge process biological sewage treatment device consists of a membrane bioreactor, a first water inlet pipe, a first sludge discharge pipe, a membrane module and first aeration equipment; the first aeration equipment consists of an aeration head, a first regulating valve, a first air inlet pipe, a first air compressor, a first lead and a first time relay;

the first water inlet pipe is communicated with the side wall of the upper end of the membrane bioreactor, the first sludge inlet pipe is communicated with the bottom wall of the membrane bioreactor, the first sludge discharge pipe is communicated with the side wall of the lower end of the membrane bioreactor, the aeration head is installed at the bottom in the membrane bioreactor, the aeration head is communicated with a first air compressor outside the membrane bioreactor through a first air inlet pipe, the first regulating valve is installed on the first air inlet pipe, the first time relay is connected with the first air compressor through a first lead, and the membrane module is arranged in the middle of the membrane bioreactor;

Furthermore, the material of the outer spherical shell is polyurethane or high-density polyethylene, the size of the outer spherical shell is 6cm multiplied by 6 cm-10 cm multiplied by 10cm, the shell is provided with latticed openings, and the spherical shell is formed by combining an upper shell and a lower shell in an inner buckling mode.

Furthermore, a plurality of S-shaped bent holes (shown in figure 3) with the width of 2-3 mm are uniformly distributed in the packing layer, and the S-shaped bent holes are criss-cross and communicated up and down. The filler layer 38-2 is made of a modified hydrophilic polypropylene material.

when the system starts to operate, sewage to be treated is injected into the membrane bioreactor through the first water inlet pipe for treatment, the treated sewage sludge is guided into the sludge reduction device for treatment through the first sludge discharge pump, sludge-water mixed liquid treated by worm predation and enhanced phosphorus release areas is discharged into the sludge-water separation and precipitation area, and the sludge precipitated in the sludge-water separation and precipitation area is pumped into the membrane bioreactor through the second sludge discharge pump; then directly discharging the sludge supernatant obtained by the treatment of the sludge-water separation and precipitation zone into a phosphate precipitation method phosphorus recovery reactor through a first sewage pump for phosphorus resource recovery; pumping the recovered sludge supernatant into a membrane bioreactor through a second sewage pump, and carrying out the next period operation;

wherein, during the period from one cycle of the operation of the sewage sludge combined treatment system to the end of the operation of the system: before the operation period of an MBR (membrane bioreactor) activated sludge process biological sewage treatment device is finished, discharging activated sludge in the MBR activated sludge process biological sewage treatment device into a worm predation and enhanced phosphorus release area through a sludge discharge pump at a flow rate which accounts for 5-20% of the water inlet flow rate of the MBR activated sludge process biological sewage treatment device; before the activated sludge is discharged into a worm predation and enhanced phosphorus release area, firstly, the precipitated sludge in a sludge-water separation and precipitation area in a sludge reduction device is discharged into an MBR (membrane bioreactor) activated sludge process biological sewage treatment device through a second sludge discharge pump at the flow rate of 2-7% of the water inlet flow rate of the MBR activated sludge process biological sewage treatment device, and the sludge supernatant is discharged into a phosphate precipitation process phosphorus recovery reactor at the flow rate of 3-13% of the water inlet flow rate of the MBR activated sludge process biological sewage treatment device; before sludge-water mixed liquor in a sludge-water separation and precipitation area in a sludge reduction device is injected into an MBR (membrane bioreactor) activated sludge process biological sewage treatment device and a phosphate precipitation process phosphorus recovery reactor, sludge supernatant after precipitation treatment in the phosphate precipitation process phosphorus recovery reactor is mixed with inlet water of the MBR activated sludge process biological sewage treatment device through a second sewage pump and enters the MBR activated sludge process biological sewage treatment device;

during the operation of the system, monitoring the water quality of worm predation and intensified phosphorus release areas by using a water quality multi-parameter online monitor;

wherein, in the operation process of the MBR activated sludge process biological sewage treatment device, the hydraulic retention time is controlled to be 7-8 h; the sludge retention time is controlled to be 30-35 days; the concentration of dissolved oxygen is 3-5 mg/L; the sludge concentration is 8000-10000 mg/L. And in the operation process of the sludge reduction device, the hydraulic retention time is 10-12 h.

Further, the phosphorus recovery reactor may have any one of a phosphate precipitation method of hydroxyapatite, aluminum phosphate, iron phosphate, vivianite, struvite (MAP), and the like.

Compared with the prior art, the invention has the following advantages:

1. the invention realizes the high-efficiency sewage treatment, synchronous sludge reduction and high-efficiency phosphorus resource recovery by combining the sludge reduction device, the phosphate precipitation method phosphorus recovery device and the activated sludge method biological sewage treatment device; the invention is based on the principle of biological predation and phosphate precipitation method phosphorus recovery, and particularly designs and combines a sludge reduction device with enhanced phosphorus release effect and a phosphate precipitation method phosphorus recovery device for synchronously and efficiently recovering phosphorus resources, thereby effectively solving the problems of low recovery efficiency of the phosphorus resources of sewage sludge and difficult stabilization and standard reaching of the effluent quality, realizing the synchronous and efficient treatment and phosphorus resource recovery of the sewage sludge, and ensuring the stabilization and standard reaching of the effluent quality, the efficient sludge reduction and the efficient phosphorus resource recovery of a combined treatment system.

2. The invention develops a novel biological predatory sludge decrement reactor with a special structure and a control mode, realizes aerobic-micro-aerobic-anaerobic dissolved oxygen gradient distribution in space and time dimensions in a worm predation and enhanced phosphorus release region, establishes the synergistic action of worm predation and microorganism metabolism, ensures that the sludge structure is destroyed by the worm predation to promote the release of carbon, nitrogen and phosphorus pollutants, realizes the attenuation and the removal of carbon and nitrogen by the action of decoupling, maintaining metabolism, nitrification, denitrification and the like of microorganisms along with the change of a substrate and a dissolved oxygen environment, saves the cost of an external carbon source in a denitrification process, simultaneously utilizes organic matters released by the worm predation by phosphorus accumulating bacteria to further enhance the release of phosphorus in sludge in an anaerobic environment, changes the structural characteristics of activated sludge after the biological predation, is more favorable for the phosphorus accumulating bacteria to release phosphorus from biomass, the problem of the anaerobic pool phosphorus release efficiency that traditional mud process decrement sidestream phosphorus recovery faced is low is solved, has created the advantage for the high-efficient recovery of phosphorus resource, therefore, the whole set of sludge decrement device has the high-efficient decrement of synchronous mud and strengthens the phosphorus release effect.

3. According to the novel biological predatory sludge reduction reactor with the special structure and the special control mode, phosphorus-rich sewage and predated sludge in the sludge-water separation settling zone are effectively separated, the upper end of the shared side wall of the sludge-water separation settling zone and the worm predation and enhanced phosphorus release zone is provided with the overflow weir, the overflow weir is arranged in the sludge-water separation settling zone, the impact of aeration disturbance of the worm predation and enhanced phosphorus release zone on sludge-water precipitation separation is reduced, the precipitation separation efficiency of the phosphorus-rich sewage and the sludge is improved, the influence of complex components in the sludge on phosphorus purity in phosphate precipitates and the influence of sludge load on phosphorus recovery in a phosphate precipitation method are reduced, the synchronous sludge reduction and phosphorus recovery efficiency are improved, and the risk of secondary pollution is reduced. In addition, the novel sludge reduction reactor has a compact structure, does not need an external sedimentation tank, saves the floor area and reduces the cost.

4. The porous suspension spherical filler in the sludge reduction device does not need a fixed frame, can be directly suspended between two layers of partition nets, and can be uniformly distributed in the longitudinal direction, the water flow direction is from bottom to top, and the bottom is alternatively aerated variably, so that the porous suspension spherical filler can be fully contacted with sewage sludge in the longitudinal direction, can effectively cut bubbles, improves the oxygen transfer rate and the utilization rate, has small resistance, good water distribution and gas distribution performance, strong impact load resistance, and is not easy to lose the filler in the balls, and the porous suspension spherical filler can freely swing under the disturbance of water flow and air flow, so that an aged biological membrane and dead worms can be quickly fallen off, worms and microbial metabolites are prevented from being excessively accumulated in a local area and the sludge and the sewage are fully mixed, and the efficient synchronous treatment of the sewage and the sludge is facilitated; the packing layer is made of biocompatible hydrophilic modified polypropylene, S-shaped bent holes which are vertically and horizontally staggered and communicated are uniformly distributed in the packing layer, and the packing layer is adaptive to the physiological characteristics of the worms such as hole residence, drilling holes and the like, so that the efficient attachment of the worms is facilitated, a place for the growth of the worms to avoid external interference and stimulation is provided, and the risk of the worms being taken away by water flow is effectively reduced; the variable aeration devices are arranged in a shape of a Chinese character 'mu', uniform aeration in worm predation and strengthened phosphorus release areas can be realized, favorable conditions are provided for the synergistic effect of worm predation and microbial metabolism, aerobic-micro-aerobic-anaerobic micro-environments can be formed in the internal space of the porous suspended spherical filler under the aerobic-micro-aerobic environment alternative variable aeration conditions, the biofilm hanging speed of the biofilm can be accelerated by the bioaffinity hydrophilic modified polypropylene filler layer, an anaerobic biofilm, a facultative biofilm and an aerobic biofilm are formed gradually from inside to outside, and the functional floras of the biofilm are strengthened through worm predation screening and acclimation in the aerobic-micro-aerobic-anaerobic environment. The special porous hydrophilic attached combined filler structure and arrangement form, the aeration device structure and arrangement form and the system operation control mode can strengthen the synergistic effect of worm predation and microorganism metabolism, improve the oxygen transfer rate and utilization rate, accelerate the biofilm formation speed of functional flora and improve the worm activity and attachment density, thereby improving the synchronous sludge reduction and phosphorus release efficiency.

5. The phosphate precipitation method of the invention recovers phosphorus, the sludge has higher phosphorus content in the supernatant after the synergistic effect of worm predation enhanced phosphorus release and phosphorus accumulation bacteria anaerobic phosphorus release, and provides favorable conditions for the phosphate precipitation method to efficiently recover phosphorus resources in sewage sludge, therefore, the phosphate precipitation method recovers the phosphorus resources from the sewage sludge, not only can solve the problem of water eutrophication caused by overhigh phosphorus content in water, but also can relieve the shortage of phosphorus resources, and realizes the recycling economy of resource recovery.

6. The system has simple and compact structure, stable and reliable operation, convenient maintenance and management, easy realization of automatic control, no need of changing the original sewage treatment facility, less investment and stronger operability. The invention can stably and effectively realize ecological cooperative treatment of sewage and sludge and high-efficiency recovery of nitrogen and phosphorus resources, and has wide popularization prospect.

7. The sludge reduction effect of the invention can reach 88-95%, the removal rate of ammonia nitrogen reaches 95-98%, the removal rate of total phosphorus reaches 92-94%, and the phosphorus recovery rate can reach 35-65%.

Drawings

FIG. 1 is a front view of the overall structure of a first embodiment of the present invention, in which arrows indicate the direction of sewage sludge flow;

FIG. 2 is a front view of the overall structure of a second embodiment of the present invention, in which arrows indicate the direction of sewage sludge flow;

FIG. 3 is a front view of a porous suspended spherical packing of the present invention;

FIG. 4 is a partially enlarged view of an "S" shaped curved cavity in the packing layer of the present invention;

FIG. 5 is a schematic view of the installation of the variable micro-pore aeration apparatus according to the present invention;

FIG. 6 is a schematic view of the screen installation of the present invention;

FIG. 7 is a front view of the overall structure of a third embodiment of the present invention; the arrows in the figure indicate the sewage sludge flow direction.

Detailed Description

For the purpose of promoting a clear understanding of the objects, aspects and advantages of the embodiments of the invention, reference will now be made in detail to the embodiments of the present disclosure, and it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the disclosure.

The exemplary embodiments of the present invention and the description thereof are provided to explain the present invention and not to limit the present invention.

Example 1

Specifically describing the present embodiment with reference to fig. 1-6, the combined sewage-sludge treatment system for simultaneous sludge reduction and phosphorus recovery of the present embodiment is composed of a sequencing batch activated sludge process biological sewage treatment device, a second regulating valve 10, a first sludge pump 11, a sludge reduction device, a fifth regulating valve 25, a second sludge pump 26, a third regulating valve 16, a first sewage pump 17, a phosphate precipitation process phosphorus recovery device, a fourth regulating valve 22 and a second sewage pump 23;

the sequencing batch activated sludge process biological sewage treatment device consists of a sequencing batch activated sludge process bioreactor 2, a first water inlet pipe 1, a first sludge inlet pipe 27, a first sludge discharge pipe 9 and first aeration equipment; the first aeration equipment consists of an aeration head 3, a first regulating valve 4, a first air inlet pipe 5, a first air compressor 6, a first lead 7 and a first time relay 8;

the sludge reduction device consists of a sludge reduction reactor, a separation net 34, a porous suspended spherical filler 38, a water quality multi-parameter online monitor 14, a second aeration device, a second sludge inlet pipe 12, a second sludge discharge pipe 24 and a first sludge discharge pipe 15; the sludge reduction reactor consists of a worm predation and enhanced phosphorus release area 13, a baffle 37 and a mud-water separation and precipitation area 35; the second aeration equipment is a variable aeration device and consists of a second time relay 28, a second lead 29, a second air compressor 30, a second air inlet pipe 31, an automatic gas flow regulator 32 and a variable microporous aeration pipe 33; the porous suspension spherical packing 38 consists of a spherical shell 38-1, a packing layer 38-2 filled inside the spherical shell 38-1 and packing 38-3 woven outside the spherical shell 38-1 in a crossed manner;

the phosphate precipitation method phosphorus recovery device consists of a phosphate precipitation method phosphorus recovery reactor 19, a mechanical stirrer 20, a second water inlet pipe 18 and a second water discharge pipe 21;

the first water inlet pipe 1 is communicated with the side wall of the upper end of the sequencing batch activated sludge process bioreactor 2, the first sludge inlet pipe 27 is communicated with the side wall of the lower end of the sequencing batch activated sludge process bioreactor 2, the first sludge discharge pipe 9 is communicated with the bottom wall of the sequencing batch activated sludge process bioreactor 2, the aeration head 3 is installed at the bottom inside the sequencing batch activated sludge process bioreactor 2, the aeration head 3 is communicated with a first air compressor 6 outside the sequencing batch activated sludge process bioreactor 2 through a first air inlet pipe 5, the first regulating valve 4 is installed on the first air inlet pipe 5, and the first time relay 8 is connected with the first air compressor 6 through a first lead 7;

the second sludge inlet pipe 12 is communicated with the side wall at the lower end of the worm predation and enhanced phosphorus release region 13 of the sludge reduction reactor, the worm predation and enhanced phosphorus release region 13 is communicated with the mud-water separation and sedimentation region 35 through an overflow weir 36 at the upper end of one side wall, the mud-water separation and sedimentation region 35 is divided into two parts by a baffle plate 37, the second sludge outlet pipe 24 is communicated with a sludge hopper at the lower end of the mud-water separation and sedimentation region 35, the first water outlet pipe 15 is communicated with the side wall at the upper end of the mud-water separation and sedimentation region 35, the water quality multi-parameter online monitor 14 is arranged at the middle upper part in the worm predation and enhanced phosphorus release region 13 and measures the pH, the temperature and the dissolved oxygen water quality indexes in real time in an online manner, the partition nets 34 are movably arranged at intervals in the worm predation and enhanced phosphorus release region 13 in a layering manner, the porous suspension spherical fillers 38 are arranged between the two partition nets 34, a plurality of variable air outlet holes are uniformly distributed on the inner wall of the microporous aeration pipe 33, the aperture diameter variable range is 0.5-3.0 mm, the variable microporous aeration pipes 33 are arranged below the lowermost end separation net 34 in the worm predation and intensified phosphorus release region 13 in a shape like a Chinese character 'mu', the variable microporous aeration pipes 33 are communicated with a second air compressor 30 outside the worm predation and intensified phosphorus release region 13 through second air inlet pipes 31, the automatic air flow regulator 32 is arranged on the second air inlet pipes 31, the automatic air flow regulator 32 is communicated with the water quality multi-parameter online monitor 14 through an automatic control system, the air flow entering the variable microporous aeration pipes 33 can be automatically regulated according to the dissolved oxygen concentration of sludge-water mixed liquid in the worm predation and intensified phosphorus release region 13 after the automatic air flow regulator is arranged, variable aeration is realized, and the second time relay 28 is connected with the second air compressor 30 through a second lead 29;

the mechanical stirrer 20 is arranged in the phosphate precipitation process phosphorus recovery reactor 19, the second water inlet pipe 18 is communicated with the side wall of the upper end of the phosphate precipitation process phosphorus recovery reactor 19, and the second water outlet pipe 21 is communicated with the side wall of the lower end of the phosphate precipitation process phosphorus recovery reactor 19;

first sludge pipe 9 advances mud pipe 12 intercommunication through a dredge pump 11 and second, first sludge pipe 27 is through No. two dredge pumps 26 and second sludge pipe 24 intercommunication, first sludge pipe 15 is through a sewage pump 17 and second inlet tube 18 intercommunication, second drain pipe 21 is through No. two sewage pumps 23 and first inlet tube 1 intercommunication, No. two governing valves 10 are installed on first sludge pipe 12, No. five governing valves 25 are installed on second sludge pipe 24, No. three governing valve 16 is installed on first drain pipe 15, No. four governing valves 22 are installed on second drain pipe 21.

Referring to fig. 3 and fig. 6, the separating net 34 of the present embodiment is movably installed in the worm predation and enhanced phosphorus release area 13 at equal intervals, the porous suspension spherical filler 38 is placed between the two layers of separating nets 34, the spherical shell 38-1 outside the porous suspension spherical filler 38 is made of polyurethane or high density polyethylene, the size is 6cm × 6 cm-10 cm × 10cm, the shell is provided with latticed openings, and the spherical shell 38-1 is formed by combining an upper shell and a lower shell. So set up, moreover, the steam generator is simple in structure, it is convenient to dismantle, do not need fixed frame, but direct suspension is between two-layer separation net, and realize evenly distributed on vertical, the rivers direction is from bottom to top, but bottom variable aeration in turn, porous suspension spherical filler both can be in vertical fully contact with sewage mud, can effectively cut the bubble again, improve oxygen transfer rate and utilization ratio, and the resistance is little, the water distribution, the gas distribution performance is good, impact load is strong, the interior filler of ball is difficult for the loss, and porous suspension spherical filler freely swings under the disturbance of rivers and air current, can make the quick of ageing biomembrane and dead worm drop, prevent the worm, microorganism metabolite excessively accumulates and mud sewage intensive mixing in local area, be favorable to sewage mud's high-efficient synchronous processing.

The embodiment is described by combining fig. 3 and fig. 4, the packing layer 38-2 of the embodiment is made of modified hydrophilic polypropylene material, a large number of S-shaped bent holes with the width of 2-3 mm are uniformly distributed on the packing layer 38-2, and the large number of holes are vertically and horizontally staggered and communicated with each other and are adapted to physiological characteristics of worm such as hole settlement, hole drilling and the like, so that the efficient attachment of the worm is facilitated, a place for the worm to grow and avoid external interference and stimulation is provided, and the risk that the worm is taken away by water flow is effectively reduced. The device has the characteristics of high permeability, compact arrangement, large specific surface area and the like, is favorable for high-density and stable fixation of worms, enables the worms to have good ecological stability and physiological activity, and obviously improves the sludge reduction efficiency.

Referring to fig. 5, in the embodiment, the variable microporous aeration pipes 33 are arranged in a "mesh" shape, so that uniform aeration in the worm predation and enhanced phosphorus release regions can be realized, favorable conditions are provided for the synergistic effect of worm predation and microbial metabolism, under the alternate aeration condition of aerobic-micro-aerobic environment, an aerobic-micro-aerobic-anaerobic micro-environment is formed in the inner space of the porous suspension spherical packing layer 38-2, the biofilm formation speed of the biofilm is increased by the bioaffinity hydrophilic modified polypropylene packing layer 38-2, an anaerobic biofilm, a facultative biofilm and an aerobic biofilm are formed gradually from inside to outside, the functional flora of the biofilm is enhanced through worm predation screening, acclimation in the alternate aerobic-micro-aerobic-anaerobic environment, and the like, and the functional flora realizes carbon sequestration through metabolism, nitrification, denitrification and the like, The removal of nitrogen pollutants relieves the load impact of carbon and nitrogen pollutants released in the worm predation process on a main stream sewage treatment system, a large amount of phosphorus pollutants can be released in the worm predation process, the relative content of the phosphorus pollutants is far higher than that of the carbon and nitrogen pollutants, meanwhile, under an anaerobic environment, phosphorus accumulating bacteria can further strengthen the release of phosphorus in sludge by using a carbon source released by worm predation, the structural characteristics of activated sludge after biological predation are changed, the phosphorus accumulating bacteria can release phosphorus from biomass more favorably, the release rate of phosphorus is improved, favorable conditions are created for phosphorus recovery by a phosphate precipitation method, and the recovery efficiency of phosphorus in sewage sludge is obviously improved.

The sewage treatment of the treatment system of this example employs an SBR process, i.e., a continuous batch activated sludge process. The effective volume of the sequencing batch activated sludge biological sewage treatment device is 150L.

The operation mode of the sequencing batch activated sludge process biological sewage treatment device in the embodiment is as follows: each period is 8 hours, water inflow is 0.5 hour, aeration is 5 hours, sedimentation is 2 hours, water drainage is 0.5 hour, 3 running periods are carried out in one day, and the water inflow and the water drainage of each period are both 100L; other operating parameters were: dissolved oxygen is controlled to be 3-4 mg/L, sludge concentration is maintained to be 3000-4000 mg/L, and system water inlet adopts artificial simulation domestic sewage.

The system operates for 20 days, when the system starts to operate, town sewage to be treated is injected into the sequencing batch activated sludge process bioreactor 2 through the first water inlet pipe 1 for treatment, the treated sewage sludge is led into a sludge reduction device for treatment through the first sludge discharge pump 11, sludge-water mixed liquid treated by the worm predation and enhanced phosphorus release region 13 is discharged into a sludge-water separation and precipitation region 35, and sludge precipitated by the sludge-water separation and precipitation region 35 is pumped into the sequencing batch activated sludge process bioreactor 2 through the second sludge discharge pump 26; then directly discharging the sludge supernatant obtained by the treatment in the sludge-water separation and precipitation zone 35 into an MAP method phosphorus recovery reactor 19 through a first sewage pump 17 for nitrogen and phosphorus resource recovery; pumping the recovered sludge supernatant into a sequencing batch activated sludge process bioreactor 2 through a second sewage pump 23, and carrying out the next cycle operation;

before the operation cycle of a sequencing batch activated sludge process biological sewage treatment device is finished, discharging activated sludge in a 15L sequencing batch activated sludge process biological sewage treatment device into a worm predation and enhanced phosphorus release region 13 of a sludge reduction device, before discharging 5L of precipitated sludge in a sludge-water separation settling region 35 in the sludge reduction device into an SBR treatment device and 10L of sludge supernatant into an MAP process phosphorus recovery device, and mixing the 10L of sludge supernatant subjected to precipitation treatment in the MAP process phosphorus recovery device with water entering the SBR treatment device to enter a mainstream sewage treatment system; in the operation process of the sludge reduction device, the sludge retention time is 15 days, the second air compressor 30 carries out aerobic-micro-aerobic intermittent variable aeration on the sludge reduction device, the gas flow automatic regulator 32 regulates the continuous gas supply amount of the second air compressor 30, and the intermittent variable aeration can be realized through a time relay28, on one hand, the dissolved oxygen concentration of the sludge mixed liquor is maintained at DO (dissolved oxygen concentration) with maximum worm sludge decrement, on the other hand, the aged biological membrane on the filler and the dead worms are rapidly fallen off, thus preventing the worms and microbial metabolites from being excessively accumulated in local areas, and being beneficial to the fixation of the worms and the full mixing of sludge and sewage; monitoring DO concentration in a worm predation and enhanced phosphorus release area 13 of the sludge reduction device by using a water quality multi-parameter online monitor 14, wherein the DO concentration is maintained at 0.5-1.0 mg/L, the temperature is 23 +/-2 ℃, and the pH is 6.5-9; adding MgCl into phosphorus recovery device by MAP method₂·6H₂O precipitant, regulating Mg²⁺、PO₄ ^3-And NH₄ ⁺The molar ratio of (1.1-1.2): 1: 1, adding a precipitator, adding NaOH solution, adjusting the pH value of the sludge supernatant to 9-10, setting the stirring speed of a mechanical stirrer 20 to be 200r/min, setting the mixing time to be 1-2 min, and setting the precipitation time to be 15 min.

As a comparative example: the operation mode of the SBR process is the same as that of the sewage sludge combined treatment system for synchronous sludge reduction and phosphorus recovery in the above embodiment except that the sewage sludge is directly discharged into the MAP method phosphorus recovery reactor 19 for nitrogen and phosphorus resource recovery without passing through the sludge-water separation settling zone 35.

Experimental results of continuous operation of the system: COD of system inlet water is 350-400 mg/L, ammonia nitrogen concentration is 25-28 mg/L, total nitrogen concentration is 27-31mg/L, total phosphorus concentration is 4-6mg/L, the last 20 days, namely, sludge reduced by 13 weight percent in the worm predation and enhanced phosphorus release region is directly discharged into the MAP method phosphorus recovery reactor 19 without passing through the mud-water separation and precipitation region 35, COD removal rate is 92.7%, ammonia nitrogen removal rate is 92.4%, total nitrogen removal rate is 83.6%, total phosphorus removal rate is 81.2%, and phosphorus recovery rate is 34.2%; after 20 days, after the treatment of the sewage sludge combined treatment system for synchronous sludge reduction and phosphorus recovery, the sludge reduction effect of the whole sewage sludge combined treatment and resource recovery system is up to 89%, the COD removal rate is 93.5%, the ammonia nitrogen removal rate is 95.0%, the total nitrogen removal rate is 87.0%, the total phosphorus removal rate is 92.1%, and the phosphorus recovery rate is 41.7%. The system successfully realizes the ecological cooperative treatment of sewage and sludge and the high-efficiency recovery of phosphorus resources.

Example 2

In this example, a comparative experiment was performed by changing the form of the filler and the aeration mode, and five sets of sludge reduction and phosphorus recovery coupled sewage sludge combined treatment systems (respectively marked as SBR-WP) were used, including a porous suspended spherical filler (without a filler layer inside), a porous suspended spherical filler (polyurethane sponge filler layer), a porous suspended spherical filler (bioaffinity hydrophilic modified polypropylene filler layer 38-2), a conventional fixed plate type filler (bioaffinity hydrophilic modified polypropylene filler layer 38-2), and a common tubular aeration system (respectively marked as SBR-WP)₁-MAP、SBR-WP₂-MAP、SBR-WP₃-MAP、SBR-WP₄-MAP、SBR-WP₅MAP process) and the system was operated continuously for 20d, the results of the experiment are shown in Table 1.

TABLE 1 Experimental results of five sets of sewage and sludge combined treatment systems

From the results of the comparative experiments, SBR-WP₃The MAP phosphate precipitation process has the best sewage and sludge treatment effect, namely the synchronous sludge reduction and phosphorus recovery sewage and sludge combined treatment system has obvious synergistic effect of the filler arrangement form and the aeration mode, and the synergistic effect is not obvious. The sewage sludge combined treatment system for synchronous sludge reduction and phosphorus recovery successfully realizes ecological cooperative treatment of sewage sludge and efficient recovery of phosphorus resources.

Example 3

The sewage-sludge combined treatment system for synchronous sludge reduction and phosphorus recovery of the present embodiment is described with reference to fig. 3-7, and comprises a membrane biological sewage treatment device, a second regulating valve 10, a first sludge discharge pump 11, a sludge reduction device, a fifth regulating valve 25, a second sludge discharge pump 26, a third regulating valve 16, a first sewage pump 17, a phosphate precipitation phosphorus recovery device, a fourth regulating valve 22, and a second sewage pump 23;

the membrane biological sewage treatment device consists of a membrane bioreactor 2, a first water inlet pipe 1, a first sludge inlet pipe 27, a first sludge discharge pipe 9, a membrane component 39 and first aeration equipment; the first aeration equipment consists of an aeration head 3, a first regulating valve 4, a first air inlet pipe 5, a first air compressor 6, a first lead 7 and a first time relay 8;

the first water inlet pipe 1 is communicated with the upper end side wall of the membrane bioreactor 2, the first sludge inlet pipe 27 is communicated with the bottom wall of the membrane bioreactor 2, the first sludge discharge pipe 9 is communicated with the lower end side wall of the membrane bioreactor 2, the aeration head 3 is installed at the bottom in the membrane bioreactor 2, the aeration head 3 is communicated with a first air compressor 6 outside the membrane bioreactor 2 through a first air inlet pipe 5, the first regulating valve 4 is installed on the first air inlet pipe 5, the first time relay 8 is connected with the first air compressor 6 through a first lead 7, and the membrane module 39 is arranged in the middle of the membrane bioreactor 2;

the second sludge inlet pipe 12 is communicated with the side wall at the lower end of the worm predation and enhanced phosphorus release region 13 of the sludge reduction reactor, the worm predation and enhanced phosphorus release region 13 is communicated with the mud-water separation and precipitation region 35 through an overflow weir 36 at the upper end of a side wall, the mud-water separation and precipitation region 35 is divided into two parts by a baffle 37, the second sludge outlet pipe 24 is communicated with a sludge hopper at the lower end of the mud-water separation and precipitation region 35, the first water outlet pipe 15 is communicated with the side wall at the upper end of the mud-water separation and precipitation region 35, the water quality multi-parameter online monitor 14 is arranged at the middle upper part inside the worm predation and enhanced phosphorus release region 13 and is used for measuring pH, temperature and dissolved oxygen water quality indexes in real time and online, the partition nets 34 are movably arranged at intervals in the worm predation and enhanced phosphorus release region 13, the porous suspension spherical filler 38 is arranged between the two partition nets 34, a plurality of variable gas outlet holes are uniformly distributed on the inner wall of the variable microporous aeration pipe 33, the aperture diameter variable range is 0.2-0.8 mm, the variable microporous aeration pipes 33 are arranged below the lowermost end separation net 34 in the worm predation and enhanced phosphorus release region 13 in a shape of a Chinese character 'mu', the variable microporous aeration pipes 33 are communicated with a second air compressor 30 outside the worm predation and enhanced phosphorus release region 13 through a second air inlet pipe 31, the automatic air flow regulator 32 is arranged on the second air inlet pipe 31, the automatic air flow regulator 32 is communicated with the water quality multi-parameter online monitor 14 through an automatic control system, after setting, the air flow entering the variable microporous aeration pipes 33 can be automatically regulated according to the dissolved oxygen concentration of sludge-water mixed liquid in the worm predation and enhanced phosphorus release region 13, so that variable aeration is realized, and the second time relay 28 is connected with the second air compressor 30 through a second lead 29;

The membrane module 39 in this example is a polyvinylidene fluoride (PVDF) hollow fiber membrane module (FP-FF 0)002, Tianjin membrane), the membrane aperture is 0.2 μm, the effective filtration area is 1.0m²；

The embodiment is described by combining fig. 3 and fig. 6, the partition nets 34 of the embodiment are movably installed in the worm predation and enhanced phosphorus release zone 13 at equal intervals in a layered manner, the porous suspension spherical filler 38 is placed between the two partition nets 34, the spherical shell 38-1 outside the porous suspension spherical filler 38 is made of polyurethane or high density polyethylene, the size of the spherical shell is 6cm x 6cm to 10cm x 10cm, the shell is provided with latticed openings, and the spherical shell 38-1 is formed by combining an upper shell and a lower shell in an inner buckle manner. So set up, moreover, the steam generator is simple in structure, it is convenient to dismantle, do not need fixed frame, but direct suspension is between two-layer separation net, and realize evenly distributed on vertical, the rivers direction is from bottom to top, but bottom variable aeration in turn, porous suspension spherical filler both can be in vertical fully contact with sewage mud, can effectively cut the bubble again, improve oxygen transfer rate and utilization ratio, and the resistance is little, the water distribution, the gas distribution performance is good, impact load is strong, the interior filler of ball is difficult for the loss, and porous suspension spherical filler freely swings under the disturbance of rivers and air current, can make the quick of ageing biomembrane and dead worm drop, prevent the worm, microorganism metabolite excessively accumulates and mud sewage intensive mixing in local area, be favorable to sewage mud's high-efficient synchronous processing.

The sewage treatment of the treatment system of the embodiment adopts an MBR (membrane bioreactor) process as follows: the sludge inoculated in the membrane bioreactor 2 is activated sludge in a sludge return pump room of a municipal sewage treatment plant, and the hydraulic retention time is controlled to be 7.06 h; the sludge retention time is controlled to be 30 days; the concentration of dissolved oxygen is 3 mg/L; the sludge concentration is 9000-10000 mg/L. Urban domestic sewage enters the membrane bioreactor 2, most organic matters in the sewage are degraded by the catabolism of microorganisms in the membrane bioreactor 2, and the treated sewage passes through the hollow fiber membrane module under the action of a vacuum pumping system to filter out water. The sewage sludge mixed liquor with high concentration in the membrane bioreactor 2 enters a worm predation and enhanced phosphorus release zone 13 in the sludge reduction device through a sludge discharge pump 11, and the sewage sludge mixed liquor treated by the worm predation and enhanced phosphorus release zone 13 in the sludge reduction device enters sludge-water separation in the sludge reduction deviceAnd (3) carrying out mud-water separation in the settling zone 35, returning the settled sludge to the membrane bioreactor 2 through a second sludge discharge pump 26, allowing the sludge supernatant to enter the MAP method phosphorus recovery device from the mud-water separation settling zone 35 through a first sewage pump 17, and allowing the treated sludge supernatant to enter a mainstream sewage treatment system through a second sewage pump 23 and the membrane bioreactor 2 by mixing water. In the operation process of the sludge reduction device, the sludge retention time is 20 days, the second air compressor 30 carries out aerobic-micro-aerobic intermittent variable aeration on the sludge reduction device, the continuous air supply quantity of the second air compressor 30 is adjusted by the automatic gas flow regulator 32, the intermittent variable aeration can be controlled by the time relay 28, on one hand, the dissolved oxygen concentration of the sludge mixed liquid is maintained at DO (dissolved oxygen concentration) with maximum worm sludge reduction, on the other hand, the aged biomembrane on the filler and the dead worms are rapidly fallen off, the worms and microbial metabolites are prevented from being excessively accumulated in a local area, and the fixation of the worms and the full mixing of sludge and sewage are facilitated; monitoring DO concentration in a worm predation and enhanced phosphorus release area 13 of the sludge reduction device by using a water quality multi-parameter online monitor 14, wherein the DO concentration is maintained at 0.5-1.0 mg/L, the temperature is 23 +/-2 ℃, and the pH is 6.5-9; adding MgCl into phosphorus recovery device by MAP method₂·6H₂O precipitant, regulating Mg²⁺、PO₄ ^3-And NH₄ ⁺The molar ratio of (1.1-1.2): 1: 1, adding a precipitator, adding NaOH solution, adjusting the pH value of the sludge supernatant to 9-10, setting the stirring speed of a mechanical stirrer 20 to be 200r/min, setting the mixing time to be 1-2 min, and setting the precipitation time to be 15 min.

Experimental results of continuous operation of the system: the system water inlet is urban domestic sewage, the water quality has certain fluctuation, the pH is 6.5-8.5, the COD and the NH are₄ ⁺The concentration ranges of the-N, TN and TP are 350-600 mg/L, 35-48mg/L, 42-47mg/L and 4-6mg/L respectively. After the treatment of the sewage sludge combined treatment system for synchronous sludge reduction and phosphorus recovery, the sludge reduction effect of the whole sewage sludge combined treatment and resource recovery system is up to 90-94%, the COD removal rate is 95.0%, the ammonia nitrogen removal rate is 98.0%, the total nitrogen removal rate is 88.7%, the total phosphorus removal rate is 94.0%, and the phosphorus recovery rate is 46.9%. Stable system operation and impact resistanceThe ecological cooperative treatment of the sewage and the sludge and the high-efficiency recovery of the phosphorus resource are successfully realized.

Example 4

In this embodiment, a comparative experiment is performed by changing the form of the filler and the aeration mode, and five sets of sewage and sludge combined treatment systems (respectively marked as MBR-WP) for synchronous sludge reduction and phosphorus recovery, such as a porous suspended spherical filler (without a filler layer inside), a porous suspended spherical filler (a polyurethane sponge filler layer), a porous suspended spherical filler (a bioaffinity hydrophilic modified polypropylene filler layer 38-2), a conventional fixed plate type filler (a bioaffinity hydrophilic modified polypropylene filler layer 38-2), and a common tubular aeration system, are adopted₁-MAP、MBR-WP₂-MAP、MBR-WP₃-MAP、MBR-WP₄-MAP、MBR-WP₅MAP Process) and the results are shown in Table 2.

TABLE 2 Experimental results of five sets of sewage and sludge combined treatment system

The result of the comparative experiment can show that the MBR-WP₃The MAP process has the best sewage and sludge treatment effect, particularly has obvious nitrogen and phosphorus removal effect and sludge reduction effect, namely the synergistic effect of the filler arrangement form and the aeration mode in the sewage and sludge combined treatment system for synchronously reducing the sludge and recovering the phosphorus is obvious and has no defect. The sewage sludge combined treatment system for synchronous sludge reduction and phosphorus recovery has stable operation and strong impact resistance, and successfully realizes ecological cooperative treatment of sewage sludge and efficient recovery of phosphorus resources.

Claims

1. A sewage and sludge combined treatment system based on biological predation synchronous sludge reduction and phosphorus recovery comprises an activated sludge process biological sewage treatment device, a second regulating valve (10), a first sludge pump (11), a sludge reduction device, a fifth regulating valve (25), a second sludge pump (26), a third regulating valve (16), a first sewage pump (17), a phosphate precipitation process phosphorus recovery device, a fourth regulating valve (22) and a second sewage pump (23); the method is characterized in that:

the activated sludge process biological sewage treatment device consists of an activated sludge process bioreactor (2), a first water inlet pipe (1), a first sludge inlet pipe (27) and a first sludge discharge pipe (9);

the sludge reduction device consists of a sludge reduction reactor, a separation net (34), a porous suspended spherical filler (38), a water quality multi-parameter online monitor (14), a second aeration device, a second sludge inlet pipe (12), a second sludge discharge pipe (24) and a first sludge discharge pipe (15); the sludge reduction reactor consists of a worm predation and enhanced phosphorus release area (13), a baffle (37) and a mud-water separation and precipitation area (35); the second aeration equipment is a variable aeration device and consists of a second time relay (28), a second lead (29), a second air compressor (30), a second air inlet pipe (31), an automatic gas flow regulator (32) and a variable microporous aeration pipe (33); the porous suspension spherical packing (38) consists of a spherical shell (38-1), a packing layer (38-2) filled in the spherical shell (38-1) and a packing (38-3) which is crosswise woven outside the spherical shell (38-1);

the phosphate precipitation method phosphorus recovery device consists of a phosphate precipitation method phosphorus recovery reactor (19), a mechanical stirrer (20), a second water inlet pipe (18) and a second water discharge pipe (21);

the first water inlet pipe (1) is communicated with the upper part of the activated sludge process bioreactor (2), the first sludge inlet pipe (27) is communicated with the lower part of the activated sludge process bioreactor (2), and the first sludge discharge pipe (9) is communicated with the bottom of the activated sludge process bioreactor (2);

the second sludge inlet pipe (12) is communicated with the lower part of the worm predation and enhanced phosphorus release area (13), the worm predation and enhanced phosphorus release area (13) is communicated with a mud-water separation and precipitation area (35) through an overflow weir (36) at the upper end of a side wall, the mud-water separation and precipitation area (35) is divided into two parts by a baffle (37), the second sludge discharge pipe (24) is communicated with a sludge hopper at the bottom of the mud-water separation and precipitation area (35), the first water discharge pipe (15) is communicated with the upper part of the mud-water separation and precipitation area (35), the water quality multi-parameter online monitor (14) is arranged at the middle upper part inside the worm predation and enhanced phosphorus release area (13), the separation nets (34) are movably arranged in the worm predation and enhanced phosphorus release area (13) at equal intervals in a layered manner, the porous suspension spherical filler (38) is arranged between two adjacent separation nets (34), and a plurality of variable air outlet holes are uniformly distributed on the variable microporous aeration pipe (33), the variable range of the pore diameter is 0.5-3.0 mm, the variable pore aeration pipe (33) is arranged at the bottom of the worm predation and intensified phosphorus release area (13) in a shape like a Chinese character 'mu', the variable pore aeration pipe is communicated with a second air compressor (30) outside the worm predation and intensified phosphorus release area (13) through a second air inlet pipe (31), the automatic gas flow regulator (32) is arranged on the second air inlet pipe (31), the automatic gas flow regulator (32) is electrically connected with the water quality multi-parameter online monitor (14), and the second time relay (28) is connected with the second air compressor (30) through a second lead (29);

the mechanical stirrer (20) is arranged in the phosphate precipitation method phosphorus recovery reactor (19), the second water inlet pipe (18) is communicated with the upper part of the phosphate precipitation method phosphorus recovery reactor (19), and the second water outlet pipe (21) is communicated with the lower part of the phosphate precipitation method phosphorus recovery reactor (19);

the first sludge discharge pipe (9) is communicated with the second sludge inlet pipe (12), and a first sludge discharge pump (11) is arranged between the first sludge discharge pipe and the second sludge inlet pipe; the first sludge inlet pipe (27) is communicated with the second sludge discharge pipe (24), and a second sludge discharge pump (26) is arranged between the first sludge inlet pipe and the second sludge discharge pipe; the first drainage pipe (15) is communicated with the second water inlet pipe (18), and a first sewage pump (17) is arranged between the first drainage pipe and the second water inlet pipe; the second water discharge pipe (21) is communicated with the first water inlet pipe (1), and a second sewage pump (23) is arranged between the second water discharge pipe and the first water inlet pipe; no. two governing valves (10) are installed on first mud pipe (12), No. five governing valves (25) are installed on second mud pipe (24), No. three governing valve (16) are installed on first drain pipe (15), No. four governing valve (22) are installed on second drain pipe (21).

2. The sewage sludge combined treatment system based on the biological predation synchronous sludge reduction and phosphorus recovery as claimed in claim 1, wherein the outer spherical shell (38-1) is made of polyurethane or high density polyethylene, the size is 6cm x 6 cm-10 cm x 10cm, the shell is provided with latticed openings, and the spherical shell (38-1) is formed by combining an upper shell and a lower shell in an inner buckling manner; a plurality of S-shaped bent holes with the width of 2-3 mm are uniformly distributed in the packing layer (38-2), and the S-shaped bent holes are vertically and horizontally staggered and communicated with each other.

3. The system of claim 1, wherein the activated sludge process is a sequencing batch activated sludge process, an oxidation ditch activated sludge process, A²One or more of an O activated sludge process biological sewage treatment device and an MBR activated sludge process biological sewage treatment device.

4. The method for treating sewage sludge by using the sewage sludge combined treatment system based on the biological predation synchronous sludge reduction and phosphorus recovery as claimed in claim 1 is characterized by comprising the following steps of:

when the system starts to operate, sewage to be treated is injected into the activated sludge process bioreactor (2) through the first water inlet pipe (1) for treatment, the treated sewage and sludge are led into the sludge reduction device for treatment through the first sludge discharge pump (11), sludge-water mixed liquid treated by the worm predation and enhanced phosphorus release region (13) is discharged into the sludge-water separation and sedimentation region (35), and sludge precipitated by the sludge-water separation and sedimentation region (35) is pumped into the activated sludge process bioreactor (2) through the second sludge discharge pump (26); then directly discharging the sludge supernatant obtained by the treatment of the sludge-water separation and precipitation zone (35) into a phosphate precipitation phosphorus recovery reactor (19) through a first sewage pump (17) for phosphorus resource recovery; pumping the recovered sludge supernatant into an activated sludge process bioreactor (2) through a second sewage pump (23) for the next period of operation;

wherein, during the period from one cycle of the operation of the sewage sludge combined treatment system to the end of the operation of the system: before the operation period of an activated sludge process biological sewage treatment device is finished, the activated sludge in the activated sludge process biological sewage treatment device is discharged into a worm predation and enhanced phosphorus release area (13) through a sludge discharge pump (11) at a flow rate which accounts for 5-20% of the water inlet flow rate of the activated sludge process biological sewage treatment device; before the activated sludge is discharged into the worm predation and enhanced phosphorus release zone (13), firstly, the precipitated sludge in the sludge separation and precipitation zone (35) in the sludge reduction device is discharged into the activated sludge method biological sewage treatment device through a second sludge discharge pump (26) at the flow rate of 2-7% of the water inlet flow rate of the activated sludge method biological sewage treatment device, and the sludge supernatant is discharged into a phosphate precipitation method phosphorus recovery reactor (19) at the flow rate of 3-13% of the water inlet flow rate of the activated sludge method biological sewage treatment device; before a sludge-water mixed liquid in a sludge-water separation and precipitation zone (35) in the sludge reduction device is injected into an activated sludge process biological sewage treatment device and a phosphate precipitation process phosphorus recovery reactor (19), sludge supernatant after precipitation treatment in the phosphate precipitation process phosphorus recovery reactor (19) is mixed with inlet water of the activated sludge process biological sewage treatment device through a second sewage pump (23) and enters the activated sludge process biological sewage treatment device;

during the operation of the sewage sludge combined treatment system, the water quality of the worm predation and enhanced phosphorus release area (13) is monitored by using a water quality multi-parameter online monitor (14);

the DO concentration in the enhanced phosphorus release zone (13) is maintained at 0.5-1.0 mg/L, the temperature is 20-35 ℃, and the pH is 6.5-9.

5. The method for treating sewage sludge using a combined sewage sludge treatment system based on simultaneous sludge reduction and phosphorus recovery by biofouling according to claim 4, wherein the phosphorus recovery process of the phosphate precipitation phosphorus recovery reactor (19) is any one of hydroxyapatite, aluminum phosphate, iron phosphate, vivianite or struvite phosphate precipitation.

6. A sewage and sludge combined treatment system based on biological predation synchronous sludge reduction and phosphorus recovery comprises an activated sludge process biological sewage treatment device, a second regulating valve (10), a first sludge pump (11), a sludge reduction device, a fifth regulating valve (25), a second sludge pump (26), a third regulating valve (16), a first sewage pump (17), a phosphate precipitation process phosphorus recovery device, a fourth regulating valve (22) and a second sewage pump (23); the method is characterized in that:

the activated sludge process biological sewage treatment device is a sequencing batch activated sludge process biological sewage treatment device;

the sequencing batch activated sludge process biological sewage treatment device consists of a sequencing batch activated sludge process bioreactor (2), a first water inlet pipe (1), a first sludge inlet pipe (27), a first sludge discharge pipe (9) and first aeration equipment; the first aeration equipment consists of an aeration head (3), a first regulating valve (4), a first air inlet pipe (5), a first air compressor (6), a first lead (7) and a first time relay (8);

the first water inlet pipe (1) is communicated with the upper part of the sequencing batch activated sludge process bioreactor (2), the first sludge inlet pipe (27) is communicated with the lower part of the sequencing batch activated sludge process bioreactor (2), the first sludge discharge pipe (9) is communicated with the bottom of the sequencing batch activated sludge process bioreactor (2), the aeration head (3) is installed at the bottom of the sequencing batch activated sludge process bioreactor (2), the air inlet of the aeration head (3) is communicated with the air outlet of a first air compressor (6) outside the sequencing batch activated sludge process bioreactor (2) through a first air inlet pipe (5), the first regulating valve (4) is installed on the first air inlet pipe (5), and the first time relay (8) is connected with the first air compressor (6) through a first lead (7);

the first sludge discharge pipe (9) is communicated with the second sludge inlet pipe (12), and a first sludge discharge pump (11) is arranged between the first sludge discharge pipe and the second sludge inlet pipe;

the first sludge inlet pipe (27) is communicated with the second sludge discharge pipe (24), and a second sludge discharge pump (26) is arranged between the first sludge inlet pipe and the second sludge discharge pipe; the first drainage pipe (15) is communicated with the second water inlet pipe (18), and a first sewage pump (17) is arranged between the first drainage pipe and the second water inlet pipe; the second water discharge pipe (21) is communicated with the first water inlet pipe (1), and a second sewage pump (23) is arranged between the second water discharge pipe and the first water inlet pipe; no. two governing valves (10) are installed on first mud pipe (12), No. five governing valves (25) are installed on second mud pipe (24), No. three governing valve (16) are installed on first drain pipe (15), No. four governing valve (22) are installed on second drain pipe (21).

7. The method for treating sewage sludge by using the sewage sludge combined treatment system based on the biological predation synchronous sludge reduction and phosphorus recovery as claimed in claim 6 is characterized by comprising the following steps of:

when the system starts to operate, sewage to be treated is injected into a sequencing batch activated sludge process bioreactor (2) through a first water inlet pipe (1) for treatment, the treated sewage sludge is led into a sludge reduction device for treatment through a first sludge discharge pump (11), sludge-water mixed liquid treated by a worm predation and enhanced phosphorus release region (13) is discharged into a sludge-water separation and precipitation region (35), and the sludge precipitated by the sludge-water separation and precipitation region (35) is pumped into the sequencing batch activated sludge process bioreactor (2) through a second sludge discharge pump (26); then directly discharging the sludge supernatant obtained by the treatment of the sludge-water separation and precipitation zone (35) into a phosphate precipitation method phosphorus recovery reactor (19) through a first sewage pump (17) for phosphorus resource recovery; pumping the recovered sludge supernatant into a sequencing batch activated sludge process bioreactor (2) through a second sewage pump (23) for the next cycle operation;

wherein, during the period from one cycle of the operation of the sewage sludge combined treatment system to the end of the operation of the system: before the operation cycle of a sequencing batch activated sludge process biological sewage treatment device is finished, the activated sludge in the sequencing batch activated sludge process biological sewage treatment device is discharged into a worm predation and enhanced phosphorus release area (13) through a sludge discharge pump (11) at the flow rate of 5-20% of the water inlet flow rate of the sequencing batch activated sludge process biological sewage treatment device; before the activated sludge is discharged into the worm predation and enhanced phosphorus release zone (13), firstly, the precipitated sludge in a sludge-water separation and precipitation zone (35) in the sludge reduction device is discharged into the sequencing batch activated sludge process biological sewage treatment device through a second sludge discharge pump (26) at the flow rate of 2-7% of the water inlet flow rate of the sequencing batch activated sludge process biological sewage treatment device, and the sludge supernatant is discharged into a phosphate precipitation process phosphorus recovery reactor (19) at the flow rate of 3-13% of the water inlet flow rate of the sequencing batch activated sludge process biological sewage treatment device; before sludge-water mixed liquid in a sludge reduction device and a sludge-water separation and precipitation area (35) is injected into a sequencing batch activated sludge process biological sewage treatment device and a phosphate precipitation process phosphorus recovery reactor (19), sludge supernatant after precipitation treatment in the phosphate precipitation process phosphorus recovery reactor (19) is mixed with inlet water of the sequencing batch activated sludge process biological sewage treatment device through a second sewage pump (23) and enters the sequencing batch activated sludge process biological sewage treatment device;

the DO concentration in the enhanced phosphorus release zone (13) is maintained at 0.5-1.0 mg/L, the temperature is 20-35 ℃, and the pH value is 6.5-9;

8. A sewage and sludge combined treatment system based on biological predation synchronous sludge reduction and phosphorus recovery comprises an activated sludge process biological sewage treatment device, a second regulating valve (10), a first sludge pump (11), a sludge reduction device, a fifth regulating valve (25), a second sludge pump (26), a third regulating valve (16), a first sewage pump (17), a phosphate precipitation process phosphorus recovery device, a fourth regulating valve (22) and a second sewage pump (23); the method is characterized in that:

the activated sludge process biological sewage treatment device is an MBR activated sludge process biological sewage treatment device;

the MBR activated sludge process biological sewage treatment device consists of a membrane bioreactor (2), a first water inlet pipe (1), a first sludge inlet pipe (27), a first sludge discharge pipe (9), a membrane component (39) and first aeration equipment; the first aeration equipment consists of an aeration head (3), a first regulating valve (4), a first air inlet pipe (5), a first air compressor (6), a first lead (7) and a first time relay (8);

the first water inlet pipe (1) is communicated with the upper part of the membrane bioreactor (2), the first sludge inlet pipe (27) is communicated with the bottom of the membrane bioreactor (2), the first sludge discharge pipe (9) is communicated with the lower part of the membrane bioreactor (2), the aeration head (3) is installed at the bottom in the membrane bioreactor (2), the aeration head (3) is communicated with a first air compressor (6) outside the membrane bioreactor (2) through a first air inlet pipe (5), the first regulating valve (4) is installed on the first air inlet pipe (5), the first time relay (8) is connected with the first air compressor (6) through a first lead (7), and the membrane module (39) is arranged in the middle of the membrane bioreactor (2);

the second sludge inlet pipe (12) is communicated with the lower part of a worm predation and enhanced phosphorus release region (13) of the sludge reduction reactor, the worm predation and enhanced phosphorus release region (13) is communicated with a mud-water separation and sedimentation region (35) through an overflow weir (36) at the upper end of a side wall, the mud-water separation and sedimentation region (35) is divided into two parts by a baffle (37), the second sludge discharge pipe (24) is communicated with a sludge hopper at the bottom of the mud-water separation and sedimentation region (35), the first water discharge pipe (15) is communicated with the upper part of the mud-water separation and sedimentation region (35), the water quality multi-parameter online monitor (14) is arranged at the middle upper part inside the worm predation and enhanced phosphorus release region (13), the separation nets (34) are movably arranged in the worm predation and enhanced phosphorus release region (13) at equal intervals in a layered manner, and the porous suspended spherical filler (38) is arranged between two adjacent separation nets (34), a plurality of variable air outlets are uniformly distributed on the variable microporous aerator pipe (33), the variable range of the aperture diameter is 0.5-3.0 mm, the variable microporous aerator pipe (33) is arranged at the bottom of the worm predation and intensified phosphorus release area (13) in a shape like a Chinese character 'mu', the variable microporous aerator pipe (33) is communicated with a second air compressor (30) outside the worm predation and intensified phosphorus release area (13) through a second air inlet pipe (31), the automatic gas flow regulator (32) is arranged on the second air inlet pipe (31), the automatic gas flow regulator (32) is electrically connected with the water quality multi-parameter online monitor (14), and the second time relay (28) is connected with the second air compressor (30) through a second lead (29);

9. The method for treating sewage sludge by using the sewage sludge combined treatment system based on the biological predation synchronous sludge reduction and phosphorus recovery as claimed in claim 8 is characterized by comprising the following steps of:

when the system starts to operate, sewage to be treated is injected into the membrane bioreactor (2) through the first water inlet pipe (1) for treatment, the treated sewage and sludge are led into the sludge reduction device for treatment through the first sludge discharge pump (11), sludge-water mixed liquid treated by the worm predation and enhanced phosphorus release region (13) is discharged into the sludge-water separation and precipitation region (35), and the sludge precipitated by the sludge-water separation and precipitation region (35) is pumped into the membrane bioreactor (2) through the second sludge discharge pump (26); then directly discharging the sludge supernatant obtained by the treatment of the sludge-water separation and precipitation zone (35) into a phosphate precipitation method phosphorus recovery reactor (19) through a first sewage pump (17) for phosphorus resource recovery; pumping the recovered sludge supernatant into the membrane bioreactor (2) through a second sewage pump (23) and carrying out the next period operation;

wherein, during the period from one cycle of the operation of the sewage sludge combined treatment system to the end of the operation of the system: before the operation period of an MBR (membrane bioreactor) activated sludge process biological sewage treatment device is finished, the activated sludge in the MBR activated sludge process biological sewage treatment device is discharged into a worm predation and enhanced phosphorus release area (13) through a sludge discharge pump (11) at a flow rate which accounts for 5-20% of the water inlet flow rate of the MBR activated sludge process biological sewage treatment device; before the activated sludge is discharged into the worm predation and enhanced phosphorus release zone (13), firstly, the precipitated sludge in the sludge separation and precipitation zone (35) in the sludge reduction device is discharged into the MBR activated sludge process biological sewage treatment device through a second sludge discharge pump (26) at the flow rate of 2-7% of the water inlet flow rate of the MBR activated sludge process biological sewage treatment device, and the sludge supernatant is discharged into the phosphate precipitation process phosphorus recovery reactor (19) at the flow rate of 3-13% of the water inlet flow rate of the MBR activated sludge process biological sewage treatment device; before sludge-water mixed liquor in a sludge-water separation and precipitation zone (35) in the sludge reduction device is injected into an MBR (membrane bioreactor) activated sludge process biological sewage treatment device and a phosphate precipitation process phosphorus recovery reactor (19), sludge supernatant after precipitation treatment in the phosphate precipitation process phosphorus recovery reactor (19) is mixed with inlet water of the MBR activated sludge process biological sewage treatment device through a second sewage pump (23) and enters the MBR activated sludge process biological sewage treatment device;

during the operation of the system, the water quality of the worm predation and enhanced phosphorus release area (13) is monitored by using a water quality multi-parameter online monitor (14);

the DO concentration in the enhanced phosphorus release zone (13) is maintained at 0.5-1.0 mg/L, the temperature is 23 +/-2 ℃, and the pH value is 6.5-9;

wherein, in the operation process of the MBR activated sludge process biological sewage treatment device, the hydraulic retention time is controlled to be 7-8 h; the sludge retention time is controlled to be 30-35 days; the concentration of dissolved oxygen is 3-5 mg/L; the sludge concentration is 8000-10000 mg/L; and in the operation process of the sludge reduction device, the hydraulic retention time is 10-12 h.

10. The combined sewage sludge treatment system based on simultaneous sludge reduction and phosphorus recovery by biofouling and according to claim 9 wherein the phosphorus recovery process of the phosphate precipitation phosphorus recovery reactor (19) is any one of hydroxyapatite, aluminophosphate, ferric phosphate, vivianite or struvite phosphate precipitation.