CN211921154U

CN211921154U - Zero-discharge treatment device for reclaimed water

Info

Publication number: CN211921154U
Application number: CN201922040579.5U
Authority: CN
Inventors: 彭文博; 罗小勇; 吴正雷; 张荟钦; 史家卿; 张泉; 周明; 王磊; 夏维辰; 范克银; 党建兵
Original assignee: Jiangsu Jiuwu Hi Tech Co Ltd
Current assignee: Jiangsu Jiuwu Hi Tech Co Ltd
Priority date: 2019-11-23
Filing date: 2019-11-23
Publication date: 2020-11-13
Anticipated expiration: 2029-11-23

Abstract

The utility model relates to a zero release processing apparatus of normal water. The method comprises the following steps: the waste water tank is used for storing reclaimed water obtained after the printing and dyeing wastewater is treated; the ultrafiltration membrane is connected with the wastewater tank and is used for carrying out ultrafiltration treatment on the reclaimed water; an ion exchange resin column connected to the ultrafiltration membrane; the first reverse osmosis membrane is connected with the ion exchange resin column and is used for concentrating the produced water of the ion exchange resin column; the carbon remover is connected to the interception side of the first reverse osmosis membrane; the nanofiltration membrane is connected with the carbon remover and is used for performing nanofiltration separation treatment on the produced water obtained by the carbon remover; the crystallizer is connected to the interception side of the nanofiltration membrane; the second reverse osmosis membrane is connected to the permeation side of the nanofiltration membrane and is used for concentrating the penetrating fluid of the nanofiltration membrane; and the high-pressure reverse osmosis membrane is connected to the concentration side of the second reverse osmosis membrane and is used for concentrating the concentrated solution of the second reverse osmosis membrane.

Description

Zero-discharge treatment device for reclaimed water

Technical Field

The utility model relates to a 'zero discharge' treatment method and a device of tail water, which belongs to the technical field of water treatment, in particular to a 'zero discharge' recovery process and a device of textile wastewater.

Background

At present, the phenomena of increasingly scarce water resources and increasingly serious water pollution in China make the recycling of waste water a necessary trend. Water for textile industry in China is discharged in the sixth place of various industries, the textile industry is one of industrial departments with large water consumption and is also a large pollution discharge household of China, and the waste water reuse rate is less than 10%. The textile wastewater is large in wastewater discharge amount and large in total pollutant amount. With the increasing demand of water in the textile industry, the relative reduction of supply, the stricter of discharge standard and the increasing of water cost, the water resource saving and the water reuse rate improvement become very important and difficult tasks in the textile dyeing and finishing industry.

The textile wastewater is mainly generated in two industries of printing and dyeing and chemical fiber. The waste water mainly contains fiber, textile pulp, various dyes, chemical additives, surfactant and finishing agent. The wastewater amount is up to 100 hundred million m. The textile not only consumes much water, but also has complex and changeable wastewater components, deep chromaticity, large alkalinity and great treatment difficulty. And each 1 ton of discharged printing and dyeing wastewater pollutes 20 tons of clean water. The wastewater is treated by methods such as physical and chemical treatment, biochemical treatment, advanced oxidation and the like. The treated wastewater can meet the industrial discharge standard.

However, the salt content of the wastewater reaches 6000-10000mg/L, if the treated wastewater is directly discharged, the ecological environment of the water body is affected, and the soil can be seriously salted. Secondly, the amount of waste water is very big, and direct emission does not conform to the principle of water resource sustainable use, also increases the burden to enterprise's incoming water. In conclusion, the effluent of the textile wastewater after the treatment of physicochemical treatment, biochemical treatment, advanced oxidation and the like is not suitable for direct discharge, and needs further advanced treatment, so that the resource utilization of the wastewater and the salt is realized.

SUMMERY OF THE UTILITY MODEL

The utility model aims at: the method solves the problem that the reclaimed water obtained after conventional physicochemical, biochemical and advanced oxidation treatment of the printing and dyeing wastewater in the prior art cannot reach the standard and be discharged.

The utility model discloses in, this technology utilizes the integration of resin, freezing crystallization and membrane technique, realizes handling the purpose of the tail water after materialization, biochemical treatment of textile industry, has realized the utilization of resources of waste water and waste salt, has reduced the emission of waste water, environmental protection.

A method for treating reclaimed water with zero emission comprises the following steps:

step 1, homogenizing the reclaimed water;

step 2, removing suspended matters in the wastewater treated in the step 1 by adopting a multi-media filter;

3, performing ultrafiltration on the wastewater treated in the step 2 to further remove suspended matters in the wastewater;

step 4, removing the hardness in the wastewater by treating the wastewater subjected to ultrafiltration filtration in the step 3 with resin;

step 5, performing primary reverse osmosis treatment on the wastewater treated in the step 4, concentrating the wastewater, recycling a clear solution of reverse osmosis, and further treating a concentrated solution;

step 6, reducing carbon dioxide in the reverse osmosis concentrated solution obtained in the step 5 by using a carbon remover;

step 7, performing nanofiltration on the concentrated water without the carbon dioxide obtained in the step 6 to separate monovalent salt and divalent salt;

step 8, freezing and crystallizing the nanofiltration concentrated solution obtained in the step 7 to obtain mirabilite;

step 9, performing second-stage reverse osmosis treatment on the nanofiltration clear liquid obtained in the step 7, concentrating the wastewater, recycling the reverse osmosis clear liquid, and further treating the concentrated liquid;

step 10, performing high-pressure reverse osmosis treatment on the reverse osmosis concentrated solution obtained in the step 9, and recycling clear liquid;

and 11, using the high-pressure reverse osmosis concentrated solution obtained in the step 10 for ash spraying treatment of a power plant.

In one embodiment, in the step 2, the medium filtration is that one or a combination of more of manganese sand, activated carbon or fly ash is adopted as a filter medium; the particle size of the medium particles gradually increases from top to bottom, the particle size of the uppermost layer is 0.4-0.6 mm, the particle size of the middle layer is 0.6-1.6 mm, and the particle size of the lowermost layer is 2-4 mm.

In one embodiment, in step 3, the ultrafiltration is performed by using a ceramic ultrafiltration membrane, wherein the pore size of the membrane is in the range of 20-50 nm.

In one embodiment, in step 3, the feed to the ultrafiltration is additionally charged with a first filter aid and/or a second filter aid, which may be added in amounts of 1 to 3% by weight, respectively.

In one embodiment, the first filter aid is an aminated magnetic nano-Fe₃O₄Particles, the second filter aid is amidated magnetic nano Fe₃O₄And (3) granules.

In one embodiment, the ion exchange resin is a sodium cation exchange resin, the flow rate of the column loading liquid is 2-5 BV/h, the regeneration of the resin is realized by using hydrochloric acid and sodium hydroxide, and the regenerated liquid is returned to the homogenization treatment after being uniformly mixed.

In one embodiment, the first stage reverse osmosis and the second stage reverse osmosis are cellulose acetate membranes or polyamide based materials.

In one embodiment, in the step 5, the water recovery rate of the reverse osmosis filtration treatment of the first stage is 75-80%, and the operating pressure is in the range of 2-4 MPa.

In one embodiment, in step 7, the recovery rate of the nanofiltration membrane is 75-80%; the operating pressure is 4-8 MPa; the sodium sulfate in the nanofiltration concentrate is not less than 12 wt%.

In one embodiment, the temperature of the freezing crystallization in the step 8 is-5 to 5 ℃, the purity of the obtained sodium sulfate is 97 to 99 percent, and the yield of the sodium sulfate is not lower than 97 percent.

In one embodiment, in step 9, the reverse osmosis recovery rate is 80-85%, the operating pressure is 2-4MPa, and the salt content of the concentrate is 3-5%.

In one embodiment, the high pressure reverse osmosis has a concentrate salt content of between 8% and 10% and the concentrate is used for power plant ash injection treatment.

A device for zero discharge treatment of reclaimed water comprising:

the waste water tank is used for storing reclaimed water obtained after the printing and dyeing wastewater is treated;

the ultrafiltration membrane is connected with the wastewater tank and is used for carrying out ultrafiltration treatment on the reclaimed water;

the ion exchange resin column is connected with the ultrafiltration membrane and is used for carrying out ion exchange hardness removal treatment on penetrating fluid of the ultrafiltration membrane;

the first reverse osmosis membrane is connected with the ion exchange resin column and is used for concentrating the produced water of the ion exchange resin column;

the carbon remover is connected to the interception side of the first reverse osmosis membrane and is used for removing carbon from the concentrated solution obtained by the first reverse osmosis membrane;

the nanofiltration membrane is connected with the carbon remover and is used for performing nanofiltration separation treatment on the produced water obtained by the carbon remover;

the crystallizer is connected to the interception side of the nanofiltration membrane and is used for carrying out crystallization treatment on the concentrated solution of the nanofiltration membrane to obtain recovered mirabilite;

the second reverse osmosis membrane is connected to the permeation side of the nanofiltration membrane and is used for concentrating the penetrating fluid of the nanofiltration membrane;

and the high-pressure reverse osmosis membrane is connected to the concentration side of the second reverse osmosis membrane and is used for concentrating the concentrated solution of the second reverse osmosis membrane.

In one embodiment, the water inlet end of the ultrafiltration membrane is also provided with a medium filter, and the filler in the medium filter is selected from one of manganese sand, activated carbon or fly ash; the grain diameter of the filler in the medium filter is divided into three layers from top to bottom, the grain diameter of the uppermost layer is 0.4-0.6 mm, the grain diameter of the middle layer is 0.6-1.6 mm, and the grain diameter of the lowermost layer is 2-4 mm.

In one embodiment, the ultrafiltration membrane is a ceramic ultrafiltration membrane; the pore size of the membrane is in the range of 20-50 nm.

In one embodiment, the water inlet end of the ultrafiltration membrane is also connected with a first filter aid adding tank and/or a second filter aid adding tank which are respectively used for adding the filter aid into the inlet water of the ultrafiltration membrane; the first filter aid is aminated magnetic nano Fe₃O₄Particles, the second filter aid is amidated magnetic nano Fe₃O₄And (3) granules.

In one embodiment, the interception side of the ultrafiltration membrane is also connected with a plate and frame filter for filtering and recovering the solid in the concentrated solution of the ultrafiltration membrane.

In one embodiment, the ion exchange resin column is packed with a sodium cation exchange resin.

In one embodiment, the first reverse osmosis membrane and/or the second reverse osmosis membrane is a cellulose acetate membrane or a polyamide-based material.

In one embodiment, the high pressure reverse osmosis membrane is a disc-type high pressure reverse osmosis membrane.

The reclaimed water zero-discharge treatment device is applied to treating reclaimed water obtained by treating printing and dyeing wastewater.

Advantageous effects

1. The membrane concentration is adopted, so that the wastewater discharge is greatly reduced, and the zero-discharge process of the textile wastewater has economic feasibility; 2. the reverse osmosis membrane is adopted to treat tail water in the textile industry, and the obtained reuse water has the advantages of good water quality, stable process and the like. Can be reused as production water according to the requirement; 3. and (3) performing salt separation treatment by adopting a high-pressure nanofiltration membrane, wherein the content of sodium sulfate in the concentrated solution is more than 12%. Compared with the modes of electrodialysis and the like, the method greatly reduces energy consumption and investment; 4. the purity of the sodium sulfate obtained by the zero discharge of the textile tail water is more than 97 percent, and the resource utilization of the sodium sulfate can be realized; 5. the utility model discloses be used for spraying grey with reverse osmosis's dense solution and handle, compare with the conventional adoption evaporative crystallization, greatly reduced energy consumption and investment, avoided the processing of waste salt simultaneously.

Drawings

Fig. 1 is a process flow diagram of the present invention.

Fig. 2 is a diagram of the device of the present invention.

FIG. 3 is a graph showing the flux change of an ultrafiltration membrane.

FIG. 4 is a graph of flux change for a first stage reverse osmosis membrane.

1. A wastewater tank; 2. ultrafiltration membranes; 3. ion exchange resin column; 4. a first reverse osmosis membrane; 5. a carbon remover; 6. a nanofiltration membrane; 7. a crystallizer; 8. a second reverse osmosis membrane; 9. a high pressure reverse osmosis membrane; 10. a first filter aid addition tank; 11. a second filter aid addition tank; 12. a plate frame filter.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments. It will be understood by those skilled in the art that the following examples are illustrative of the present invention only and should not be taken as limiting the scope of the invention. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

The recitation of values by ranges is to be understood in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a concentration range of "about 0.1% to about 5%" should be interpreted to include not only the explicitly recited concentration of about 0.1% to about 5%, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and sub-ranges (e.g., 0.1% to 0.5%, 1% to 2.2%, 3.3% to 4.4%) within the indicated range. The percentages in the present invention refer to weight percentages without specific reference.

Reference throughout this specification to "one embodiment," "another embodiment," "an implementation," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment described generally throughout this application. The appearances of the same phrase in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of this application to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

The percentages in the present invention refer to mass percentages unless otherwise specified.

The utility model discloses the waste water that well will be handled is the normal water that printing and dyeing wastewater obtained after having passed through conventional materialization, biochemistry and advanced oxidation treatment, and the normal water is unsuitable for direct emission because it contains higher salinity and COD etc. consequently, need carry out advanced treatment to it, realizes the zero release of waste water to retrieve the salt wherein. The waste water mainly contains fiber, textile pulp, various dyes, chemical additives, surfactant and finishing agent. The wastewater amount is up to 100 hundred million m. The textile not only consumes much water, but also has complex and changeable wastewater components, deep chromaticity, large alkalinity and great treatment difficulty. And each 1 ton of discharged printing and dyeing wastewater pollutes 20 tons of clean water. The wastewater is treated by methods such as physical and chemical treatment, biochemical treatment, advanced oxidation and the like. The treated wastewater can meet the industrial discharge standard. The salinity content of the wastewater reaches 5000-10000mg/L, if the treated wastewater is directly discharged, the ecological environment of a water body is influenced, and the soil can be seriously salted. Secondly, the amount of waste water is very big, and direct emission does not conform to the principle of water resource sustainable use, also increases the burden to enterprise's incoming water. In conclusion, the effluent of the textile wastewater after the treatment of physicochemical treatment, biochemical treatment, advanced oxidation and the like is not suitable for direct discharge, and needs further advanced treatment, so that the resource utilization of the wastewater and the salt is realized.

In a typical embodiment, the source of the neutral water in the printing and dyeing wastewater is treated by the following method:

the bleaching and dyeing wastewater obtained from the bleaching and dyeing mill has the chroma of about 8.31 and the COD of about 12000ppm, and is black brown; mixing the waste water with other cleaning waste water in a factory, diluting the waste water by about 2-3 times, adding about 300ppm of polyaluminium chloride and 40ppm of ferric trichloride into the waste water for flocculation, adjusting the pH value to be neutral, and stirring for flocculation; then after sedimentation and quartz sand filtration, NaOH and Na are added₂CO₃Precipitating calcium and magnesium ions, adding NaOH and Na₂CO₃The amounts may be converted from stoichiometric; the waste water is subjected to wet oxidation, the oxidation temperature is controlled at 180 ℃, the pressure is controlled at about 4MPa, the COD of the waste water subjected to advanced oxidation treatment is about 60mg/L, the total hardness is about 85mg/L (the precipitation reaction is usually incomplete), and the pH is about 7, so that the waste water is used as the reclaimed water obtained by the process.

In general, the medium water of the printing and dyeing wastewater after conventional physicochemical, biochemical and advanced oxidation treatment contains COD, hardness, turbidity, sodium sulfate and sodium chloride. In one embodiment, the COD in the tail water is in the range of 30-80mg/L, the total hardness is in the range of 50-200 mg/L, the turbidity is in the range of 10-30 NTU, the sodium sulfate is in the range of 4000-6000ppm, the sodium chloride is in the range of 1000-1500 ppm, and the pH is in the range of 6-8; in the utility model, the sodium sulfate in the wastewater needs to be recycled, so that other cations except sodium ions are impurity ions, such as calcium, magnesium and the like.

The main steps of the utility model can be as follows:

step 1, homogenizing water; the function is to make the water quality of the waste water more uniform;

step 2, removing suspended matters in the wastewater treated in the step 1 by adopting a multi-media filter; some larger suspended matters in the wastewater can be removed by the step; in one embodiment, the medium filtration refers to the adoption of one or a combination of more of manganese sand, activated carbon or fly ash as a filter medium; the particle size of the medium particles gradually increases from top to bottom, the particle size of the uppermost layer is 0.4-0.6 mm, the particle size of the middle layer is 0.6-1.6 mm, and the particle size of the lowermost layer is 2-4 mm;

3, performing ultrafiltration on the wastewater treated in the step 2 to further remove suspended matters in the wastewater; the wastewater also contains some smaller particles and colloids, and can be removed through the ultrafiltration membrane in the step; the ultrafiltration membrane used in the method can be a ceramic ultrafiltration membrane, and because the printing and dyeing wastewater has the characteristic of high hardness and is subjected to reverse osmosis filtration subsequently, calcium and magnesium ions which are not removed in the precipitation reaction can be influenced in the subsequent reverse osmosis process to form scale on the surface of the reverse osmosis membrane; in the process of ultrafiltration, the fine colloid blocks the membrane pores of the ultrafiltration membrane, so that the pollution of the membrane is generated and the filtration flux of the membrane is reduced; a certain amount of ferroferric oxide nano-particles with aminated surfaces or amidated magnetic nano-Fe can be added into the feed for ultrafiltration₃O₄The granule (the preparation method can refer to the prior technical documents of Zhou hong, Zhu Ming, Pan Shi right, etc.. the synthesis and the characterization of the functionalized ferroferric oxide and the adsorption of the functionalized ferroferric oxide to calcium ions [ J]Wuhan engineering university journal, 2013, 35(4):14-20, Yongchang, Yangjun, Huping et al₃O₄Application of particles to treatment of heavy metals in wastewater [ J]Application chemical, 2017 (6); because the ammonia chemical on the surface of the magnetic ferroferric oxide can form a coordinate bond with heavy metal ions, on one hand, the magnetic ferroferric oxide can adsorb the residual heavy metal ions in the wastewater, on the other hand, the particles also play a role of a filter aid, and a protective filter cake layer is formed on the surface of the ultrafiltration membrane, so that colloidal impurities are prevented from blocking the pores of the ultrafiltration membrane, and the recovery of the flux of the ultrafiltration membrane is facilitated; presence of magnetic particlesIn the concentrated solution of ultrafiltration, the concentrated solution can be recovered by subsequent plate-and-frame filtration, and can be recovered by magnetic materials due to its magnetism for reuse. Likewise, amidated magnetic nano-Fe₃O₄The particles can also form a coordination reaction with calcium ions, can adsorb the calcium ions, and can reduce the scaling of the nanofiltration membrane.

Step 4, removing the hardness in the wastewater by treating the wastewater subjected to ultrafiltration filtration in the step 3 with resin; because the printing and dyeing wastewater has the characteristic of high hardness and contains a large amount of calcium and magnesium ions, the calcium and magnesium cannot be completely eliminated even through the double-alkali precipitation treatment, and therefore, the untreated calcium and magnesium ions can be deeply removed through the ion exchange resin. The adopted ion exchange resin is sodium type cation exchange resin, the flow rate of the column loading liquid is 2-5 BV/h, the resin regeneration adopts a method of regenerating hydrochloric acid and sodium hydroxide, and the regenerated liquid is returned to the homogenization treatment after being uniformly mixed;

5, performing primary reverse osmosis treatment on the wastewater treated in the step 4 to realize ion separation, recycling a reverse osmosis clear solution and further treating a concentrated solution; through the advanced treatment, the filtration of the ultrafiltration membrane and the treatment of the ion exchange resin, part of COD and hardness are eliminated, the wastewater is reduced through the action of the first-stage reverse osmosis, the salt in the wastewater can be concentrated, and the load pressure of the subsequent nanofiltration membrane is reduced;

step 6, reducing carbon dioxide in the reverse osmosis concentrated solution obtained in the step 5 by using a carbon remover; the equipment for removing the free carbon dioxide in water by using a blast degassing mode is characterized in that water is introduced from the upper part of the equipment, flows through the surface of a packing layer through a spraying device, and air enters from a lower air port and reversely passes through the packing layer. Free carbon dioxide in the water is rapidly desorbed into the air and discharged from the top. The water treatment process is generally arranged behind a hydrogen ion exchanger and a reverse osmosis device, and under the normal preparation condition, carbon dioxide remained in water after being degassed by a carbon remover is not more than 5 mg/L. The recovery rate of reverse osmosis filtration treatment water is 75-80%, and the operating pressure range is 2-4 MPa;

and 7, carrying out salt separation on the concentrated water without the carbon dioxide obtained in the step 6 by adopting nanofiltration. Respectively treating the clear liquid and the concentrated liquid after nanofiltration; in this step, a divalent salt (sodium sulfate) and a monovalent salt (sodium chloride) in the wastewater can be separated. The recovery rate of the nanofiltration membrane is 75-80%; the operating pressure is 4-8 MPa; sodium sulfate in the nanofiltration concentrated solution is not less than 12 wt%;

step 8, freezing and crystallizing the nanofiltration concentrated solution obtained in the step 7 to obtain high-purity mirabilite, and recycling the mother solution of frozen crystallization to a nanofiltration membrane system; after the nanofiltration membrane intercepts divalent salt, the concentrated solution at the interception side is cooled and crystallized, and mirabilite can be obtained. In the step 8, the temperature of the freezing crystallization is-5 ℃, the purity of the obtained sodium sulfate is 97-99%, and the yield of the sodium sulfate is not lower than 97%;

step 9, performing second-stage reverse osmosis treatment on the nanofiltration clear liquid obtained in the step 7 to realize ion separation, recycling the reverse osmosis clear liquid and further treating the concentrated liquid; the nanofiltration clear liquid is mainly monovalent salt, and the purpose of the reverse osmosis treatment in the second stage is to further concentrate the monovalent salt. The first section of reverse osmosis and the second section of reverse osmosis are cellulose acetate membranes or polyamide materials; the recovery rate of reverse osmosis is 80-85%, the operating pressure range is 2-4MPa, and the salt content range of the concentrated solution is 3% -5%;

step 10, performing high-pressure reverse osmosis treatment on the reverse osmosis concentrated solution obtained in the step 9; the high-pressure reverse osmosis adopts disc type high-pressure reverse osmosis, and the operating pressure is 8-12 MPa;

11, using the high-pressure reverse osmosis concentrated solution obtained in the step 10 for ash spraying treatment of a power plant; the salt content of the high-pressure reverse osmosis concentrated solution is 8-10%, and the concentrated solution is used for ash spraying treatment of a power plant;

12, mixing the high-pressure reverse osmosis clear liquid obtained in the step 10 with the first-stage reverse osmosis clear liquid and the second-stage reverse osmosis clear liquid for recycling;

based on the above method, the utility model also provides the following treatment facility, as shown in fig. 2:

the waste water tank 1 is used for storing reclaimed water obtained after the printing and dyeing wastewater is treated;

the ultrafiltration membrane 2 is connected to the wastewater tank 1 and is used for carrying out ultrafiltration treatment on reclaimed water;

the ion exchange resin column 3 is connected with the ultrafiltration membrane 2 and is used for carrying out ion exchange hardness removal treatment on the penetrating fluid of the ultrafiltration membrane 2;

the first reverse osmosis membrane 4 is connected with the ion exchange resin column 3 and is used for concentrating the produced water of the ion exchange resin column 3;

the carbon remover 5 is connected to the interception side of the first reverse osmosis membrane 4 and is used for removing carbon from the concentrated solution obtained by the first reverse osmosis membrane 4;

the nanofiltration membrane 6 is connected with the carbon remover 5 and is used for carrying out nanofiltration separation treatment on the produced water obtained by the carbon remover 5;

the crystallizer 7 is connected to the interception side of the nanofiltration membrane 6 and is used for carrying out crystallization treatment on the concentrated solution of the nanofiltration membrane 6 to obtain recovered mirabilite;

the second reverse osmosis membrane 8 is connected to the permeation side of the nanofiltration membrane 6 and is used for concentrating the penetrating fluid of the nanofiltration membrane 6;

and a high-pressure reverse osmosis membrane 9 connected to the concentration side of the second reverse osmosis membrane 8 for further concentration treatment of the concentrated solution of the second reverse osmosis membrane 8.

In one embodiment, the water inlet end of the ultrafiltration membrane 2 is also provided with a medium filter, and the filler in the medium filter is selected from one of manganese sand, activated carbon or fly ash; the grain diameter of the filler in the medium filter is divided into three layers from top to bottom, the grain diameter of the uppermost layer is 0.4-0.6 mm, the grain diameter of the middle layer is 0.6-1.6 mm, and the grain diameter of the lowermost layer is 2-4 mm.

In one embodiment, ultrafiltration membrane 2 is a ceramic ultrafiltration membrane; the pore size of the membrane is in the range of 20-50 nm.

In one embodiment, the water inlet end of the ultrafiltration membrane 2 is also connected with a first filter aid adding tank 10 and/or a second filter aid adding tank 11 which are respectively used for adding the filter aid into the inlet water of the ultrafiltration membrane 2; the first filter aid is aminated magnetic nano Fe₃O₄Particles, the second filter aid is amidated magnetic nano Fe₃O₄And (3) granules.

In one embodiment, a plate and frame filter 12 is further connected to the retentate side of the ultrafiltration membrane 2 for filtering and recovering the solids in the concentrated solution of the ultrafiltration membrane 2.

In one embodiment, the ion exchange resin column 3 is packed with a sodium cation exchange resin.

In one embodiment, the first reverse osmosis membrane 4 and/or the second reverse osmosis membrane 8 is a cellulose acetate membrane or a polyamide-based material.

In one embodiment, the high pressure reverse osmosis membrane 9 is a disc-type high pressure reverse osmosis membrane.

Example 1

The water quality of the reclaimed water obtained after the printing and dyeing wastewater is subjected to the dilution, flocculation, precipitation and hardness removal and wet oxidation treatment is as follows: water amount is 250m for dry harvest, COD is 60mg/L, total hardness is 100mg/L, turbidity is 30NTU, intake water TDS is 6577mg/L, sodium sulfate is 5177mg/L, sodium chloride is 1400mg/L, cadmium is 0.06ppm, pH is 6.5, and iron ion concentration is 1.6 mg/L.

After the multi-medium filtration, the iron ion concentration in the wastewater is 0.2mg/L, and the turbidity is 0.5 NTU. The multi-medium effluent is filtered by a ceramic ultrafiltration membrane, the membrane aperture is 50nm, and the stability of the ceramic membrane in the operation process is maintained at 154L/m²H, the operating pressure is 0.1MPa, the recovery rate is 93 percent, the effluent turbidity is 0.1NTU, and the effluent SDI 3. And removing hardness of the ultrafiltration effluent by using a sodium type cation exchange resin, wherein the water removal hardness of the resin is 5 mg/L. The resin effluent enters a first stage reverse osmosis operation system, the reverse osmosis operation pressure is 3.5MPa, and the recovery rate is 80%. The TDS of the first section of reverse osmosis clear liquid is 177mg/L, the clear liquid is recycled, and the TDS of the concentrated solution is 28544 mg/L. And the alkalinity of the concentrated solution of the first-stage reverse osmosis is reduced by a carbon remover. The effluent of the carbon remover enters a nanofiltration membrane, the recovery rate of the nanofiltration membrane is 80%, the operating pressure is 7MPa, the sulfate radical content of the concentrated solution is 116758mg/L, the TDS is 178454mg/L, and the TDS of the nanofiltration clear solution is 6830 mg/L. And crystallizing the nanofiltration membrane concentrated solution by freezing. The operation temperature is controlled between-5 ℃ and 0 ℃, and the amount of the obtained mirabilite is 2.2t/h and the water content is about 1 t; the purity of the sodium sulfate is 98 percent, and the whiteness is 82; producing about 10m of wet/h of mother liquor to reflux to the nanofiltration system. The nanofiltration clear solution is further desalted by reverse osmosis of a second section. The recovery rate of reverse osmosis in the second stage is 85 percent, the operating pressure is 3.8MPa, and the second stageTDS of the clear solution of the second-stage reverse osmosis is 205mg/L, the clear solution is recycled, TDS of the concentrated solution of the second-stage reverse osmosis is 44365mg/L, and water quantity of the concentrated solution is 7.2m for carrying out plantation/h. And (3) further concentrating the concentrated solution of the second-stage reverse osmosis by using high-pressure reverse osmosis, wherein the operation pressure is 10MPa, the salt content of the concentrated solution is 101410mg/L, the concentrated solution for 3.1m carrying out power plant ash spraying, the TDS of the clear solution is 1310mg/L, and the clear solution for 4.1m carrying out power plant ash spraying. And mixing all the clear liquid after reverse osmosis for recycling, wherein the water amount is 245 m/h, and the salt content is 200 mg/L.

Example 2

The water quality of the reclaimed water obtained after the printing and dyeing wastewater is subjected to the dilution, flocculation, precipitation and hardness removal and wet oxidation treatment is as follows: water quantity is 300m for double cropping, COD is 50mg/L, total hardness is 150mg/L, turbidity is 20NTU, intake water TDS is 5859mg/L, sodium sulfate is 4682mg/L, sodium chloride is 1178mg/L, cadmium is 0.06ppm, pH range is 6.5, and iron ion concentration is 1.3 mg/L. After the multi-medium filtration, the iron ion concentration in the wastewater is 0.3mg/L, and the turbidity is 0.7 NTU. The multi-medium effluent is filtered by a ceramic ultrafiltration membrane, the membrane aperture is 50nm, and the stability of the ceramic membrane in the operation process is maintained at 158L/m²H, the operating pressure is 0.1MPa, the recovery rate is 92%, the effluent turbidity is 0.1NTU, and the effluent SDI is 2.5. And removing hardness of the ultrafiltration effluent by using a sodium type cation exchange resin, wherein the water removal hardness of the resin is 9 mg/L. The resin effluent enters a first-stage reverse osmosis operation system, the reverse osmosis operation pressure is 3.0MPa, and the recovery rate is 80%. The TDS of the first section of reverse osmosis clear liquid is 200mg/L, the clear liquid is recycled, and the TDS of the concentrated solution is 28590 mg/L. And the alkalinity of the concentrated solution of the first-stage reverse osmosis is reduced by a carbon remover. The effluent of the carbon remover enters a nanofiltration membrane, the recovery rate of the nanofiltration membrane is 80%, the operation pressure is 7MPa, the sulfate radical content of the concentrated solution is 105200mg/L, the TDS is 161360mg/L, and the TDS of the nanofiltration clear solution is 6820 mg/L. And crystallizing the nanofiltration membrane concentrated solution by freezing. The operation temperature is controlled between-5 ℃ and 0 ℃, and the amount of the obtained mirabilite is 2.2t/h and the water content is about 1 t; the purity of the sodium sulfate is 98 percent, and the whiteness is 82; producing about 10m of wet/h of mother liquor to reflux to the nanofiltration system. The nanofiltration clear solution is further desalted by reverse osmosis of a second section. The recovery rate of the second-stage reverse osmosis is 85 percent, the operation pressure is 3.5MPa, the TDS of the clear solution of the second-stage reverse osmosis is 200mg/L, the clear solution is recycled, and the TDS of the concentrated solution of the second-stage reverse osmosis is43671mg/L, and water amount of concentrated solution 8.4 m/h. And (3) further concentrating the concentrated solution of the second-stage reverse osmosis by using high-pressure reverse osmosis, wherein the operation pressure is 10MPa, the salt content of the concentrated solution is 99824mg/L, the concentrated solution for 3.6m high speed planting is sent to a power plant for ash spraying, the TDS of the clear solution is 1310mg/L, and the clear solution for 4.8m high speed planting. And mixing all the clear liquids of the reverse osmosis for recycling, wherein the water amount is 292 m/h, and the salt content is 198 mg/L.

Example 3

After the multi-medium filtration, the iron ion concentration in the wastewater is 0.2mg/L, and the turbidity is 0.5 NTU. Adding 1wt% of ferroferric oxide nano particles with aminated surfaces into multimedia effluent, filtering by using a ceramic ultrafiltration membrane, wherein the membrane aperture is 50nm, and the stability of the ceramic membrane in the operation process is maintained at 179L/m²H, the operating pressure is 0.1MPa, the recovery rate is 94%, the effluent turbidity is 0.1NTU, the effluent SDI is 2.5, and the cadmium is reduced to 0.02 ppm. After the ultrafiltration concentrated solution is subjected to solid-liquid separation by adopting a plate-and-frame filter, magnetic particles in the ultrafiltration concentrated solution are separated by utilizing a magnet and recycled; and removing hardness of the ultrafiltration effluent by using a sodium type cation exchange resin, wherein the water removal hardness of the resin is 4 mg/L. The resin effluent enters a first stage reverse osmosis operation system, the reverse osmosis operation pressure is 3.5MPa, and the recovery rate is 85%. The TDS of the first section of reverse osmosis clear liquid is 166mg/L, the clear liquid is recycled, and the TDS of the concentrated solution is 28437 mg/L. And the alkalinity of the concentrated solution of the first-stage reverse osmosis is reduced by a carbon remover. The effluent of the carbon remover enters a nanofiltration membrane, the recovery rate of the nanofiltration membrane is 80%, the operation pressure is 7MPa, the sulfate radical content of the concentrated solution is 116443mg/L, the TDS is 17864mg/L, and the TDS of the nanofiltration clear solution is 6810 mg/L. And crystallizing the nanofiltration membrane concentrated solution by freezing. The operation temperature is controlled between-5 ℃ and 0 ℃, and the amount of the obtained mirabilite is 2.2t/h and the water content is about 1 t; the purity of the sodium sulfate is 98 percent, and the whiteness is 84; producing about 10m of wet/h of mother liquor to reflux to the nanofiltration system. The nanofiltration clear solution is further desalted by reverse osmosis of a second section. Second stage isThe recovery rate of permeation is 85%, the operation pressure is 3.5MPa, the TDS of the second-stage reverse osmosis clear solution is 186mg/L, the clear solution is recycled, the TDS of the second-stage reverse osmosis concentrated solution is 44128mg/L, and the water quantity of the concentrated solution is 7.5m for thin film plantation/h. And (3) further concentrating the concentrated solution of the second-stage reverse osmosis by using high-pressure reverse osmosis, wherein the operation pressure is 10MPa, the salt content of the concentrated solution is 101365mg/L, the concentrated solution for 3.2m topdressing/h is sent to a power plant for ash spraying, the TDS of the clear solution is 1289mg/L, and the clear solution for 4.0m topdressing/h. And mixing all the clear liquids of the reverse osmosis for recycling, wherein the water amount is 248 m/h, and the salt content is 196 mg/L. Comparing the example 3 with the example 1, it can be seen that, on one hand, heavy metal ions in water can be adsorbed by the aid of the filtration aid effect of the surface aminated ferroferric oxide nanoparticles as the ceramic ultrafiltration membrane, so that the load of subsequent ion exchange resin is reduced, and on the other hand, a protective filter cake layer is formed on the surface of the ultrafiltration membrane, so that the attenuation of membrane flux is reduced.

Example 4

The water quality of the reclaimed water obtained after the printing and dyeing wastewater is subjected to the dilution, flocculation, precipitation and hardness removal and wet oxidation treatment is as follows: water quantity is 300m for double cropping, COD is 50mg/L, total hardness is 150mg/L, turbidity is 20NTU, intake water TDS is 5859mg/L, sodium sulfate is 4682mg/L, sodium chloride is 1178mg/L, cadmium is 0.06ppm, pH range is 6.5, and iron ion concentration is 1.3 mg/L. After the multi-medium filtration, the iron ion concentration in the wastewater is 0.3mg/L, and the turbidity is 0.7 NTU. Adding 1wt% of amidated magnetic nano Fe into multi-medium water outlet₃O₄Filtering with ceramic ultrafiltration membrane with membrane aperture of 50nm, and maintaining the stability of ceramic membrane at 183L/m during operation²H, the operating pressure is 0.1MPa, the recovery rate is 94%, the effluent turbidity is 0.1NTU, the effluent SDI is 2.5, and the total hardness is reduced to 135 mg/L. After the ultrafiltration concentrated solution is subjected to solid-liquid separation by adopting a plate-and-frame filter, magnetic particles in the ultrafiltration concentrated solution are separated by utilizing a magnet and recycled; and removing hardness of the ultrafiltration effluent by using a sodium type cation exchange resin, wherein the water removal hardness of the resin is 2 mg/L. The resin effluent enters a first stage reverse osmosis operation system, the reverse osmosis operation pressure is 3.0MPa, and the recovery rate is 83 percent. The TDS of the first section of reverse osmosis clear liquid is 180mg/L, the clear liquid is recycled, and the TDS of the concentrated solution is 28110 mg/L. The first stage reverse osmosis uses the carbon remover to reduce the alkalinity in the concentrate. The effluent of the carbon remover enters a nanofiltration membrane, the recovery rate of the nanofiltration membrane is 80%, the operation pressure is 7MPa, the sulfate radical content of the concentrated solution is 103350mg/L, the TDS is 156750mg/L, and the TDS of the nanofiltration clear solution is 6760 mg/L. And crystallizing the nanofiltration membrane concentrated solution by freezing. The operation temperature is controlled between-5 ℃ and 0 ℃, and the amount of the obtained mirabilite is 2.4t/h and the water content is about 1 t; the purity of the sodium sulfate is 98.5 percent, and the whiteness is 84; producing about 10m of wet/h of mother liquor to reflux to the nanofiltration system. The nanofiltration clear solution is further desalted by reverse osmosis of a second section. The recovery rate of the second-stage reverse osmosis is 85%, the operation pressure is 3.0MPa, the TDS of the clear solution of the second-stage reverse osmosis is 180mg/L, the clear solution is recycled, the TDS of the concentrated solution of the second-stage reverse osmosis is 43447mg/L, and the water quantity of the concentrated solution is 8.2m for carrying out thin film growing. And (3) further concentrating the concentrated solution of the second stage of reverse osmosis by using high-pressure reverse osmosis, wherein the operation pressure is 10MPa, the salt content of the concentrated solution is 99423mg/L, the concentrated solution for 3.5m high power plant ash spraying is carried out, the TDS of the clear solution is 1267mg/L, and the clear solution for 4.8m high power plant ash spraying is carried out. All the clear liquids after reverse osmosis are mixed and recycled, the water content is 288 m/h, and the salt content is 179 mg/L. Comparing example 4 with example 2, it can be seen that magnetic nano-Fe is amidated₃O₄The particles are used as the filter aid of the ceramic ultrafiltration membrane, so that on one hand, calcium ions in water can be adsorbed, the hardness of wastewater is reduced, and the subsequent surface scaling phenomenon of a nanofiltration membrane can be reduced, on the other hand, a protective filter cake layer is formed on the surface of the ultrafiltration membrane, the attenuation of membrane flux is reduced, and the change of the ultrafiltration membrane flux and the change of the first section of reverse osmosis membrane flux are respectively shown in fig. 3 and fig. 4.

Claims

1. A device for treating the water with zero discharge, comprising:

the waste water tank (1) is used for storing reclaimed water obtained after the printing and dyeing wastewater is treated;

the ultrafiltration membrane (2) is connected to the wastewater tank (1) and is used for carrying out ultrafiltration treatment on reclaimed water;

an ion exchange resin column (3) connected to the ultrafiltration membrane (2) and used for carrying out ion exchange hardness removal treatment on the penetrating fluid of the ultrafiltration membrane (2);

the first reverse osmosis membrane (4) is connected with the ion exchange resin column (3) and is used for concentrating the produced water of the ion exchange resin column (3);

the carbon remover (5) is connected to the interception side of the first reverse osmosis membrane (4) and is used for removing carbon from the concentrated solution obtained by the first reverse osmosis membrane (4);

the nanofiltration membrane (6) is connected with the carbon remover (5) and is used for carrying out nanofiltration separation treatment on the produced water obtained by the carbon remover (5);

the crystallizer (7) is connected to the interception side of the nanofiltration membrane (6) and is used for carrying out crystallization treatment on the concentrated solution of the nanofiltration membrane (6) to obtain recovered mirabilite;

the second reverse osmosis membrane (8) is connected to the permeation side of the nanofiltration membrane (6) and is used for concentrating the permeation liquid of the nanofiltration membrane (6);

and a high-pressure reverse osmosis membrane (9) which is connected to the concentration side of the second reverse osmosis membrane (8) and is used for concentrating the concentrated solution of the second reverse osmosis membrane (8).

2. The reclaimed water zero-emission treatment device according to claim 1, wherein the ultrafiltration membrane (2) is a ceramic ultrafiltration membrane; the pore size of the membrane is in the range of 20-50 nm.

3. The reclaimed water zero-discharge treatment device according to claim 1, characterized in that the water inlet end of the ultrafiltration membrane (2) is further connected with a first filter aid addition tank (10) and/or a second filter aid addition tank (11) for respectively adding the filter aid to the inlet water of the ultrafiltration membrane (2).

4. The reclaimed water zero-emission treatment device according to claim 1, characterized in that a plate and frame filter (12) is connected to the interception side of the ultrafiltration membrane (2) and used for filtering and recovering the solid in the concentrated solution of the ultrafiltration membrane (2).

5. The apparatus for the treatment with zero discharge of recycled water according to claim 1, characterized in that the ion exchange resin column (3) is filled with a sodium cation exchange resin.

6. The reclaimed water zero-emission treatment device according to claim 1, wherein the first reverse osmosis membrane (4) and/or the second reverse osmosis membrane (8) is made of cellulose acetate or polyamide.

7. The apparatus for the treatment with zero discharge of reclaimed water according to claim 1, wherein the high pressure reverse osmosis membrane (9) is a disc type high pressure reverse osmosis membrane.