CN103848508A - Nitrogen-removing biological filter device and application thereof in treatment of micro-polluted source water - Google Patents
Nitrogen-removing biological filter device and application thereof in treatment of micro-polluted source water Download PDFInfo
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- CN103848508A CN103848508A CN201410127269.6A CN201410127269A CN103848508A CN 103848508 A CN103848508 A CN 103848508A CN 201410127269 A CN201410127269 A CN 201410127269A CN 103848508 A CN103848508 A CN 103848508A
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Abstract
The invention discloses a nitrogen-removing biological filter device and application thereof in treatment of micro-polluted source water. The nitrogen-removing biological filter device comprises an upward flow filter column, a water inlet slot, a water inlet tube, a water outlet tube and an outlet water collector, wherein a supporting plate and a biological filter material layer are arranged in the upward flow filter column from bottom to top in sequence; the lower end of the upward flow filter column is connected with the water inlet slot by the water inlet tube; the water inlet tube is arranged below the supporting plate; the upper end of the upward flow filter column is connected with the outlet water collector by the water outlet tube; the water outlet tube is arranged above the biological filter material layer; the water inlet tube is connected with a constant-flow pump. The nitrogen-removing biological filter device disclosed by the invention can realize synchronous nitrification and denitrification without the need of aeration in an ammonia nitrogen degrading process, so that the ammonia nitrogen is finally converted into a nitrogen gas, and therefore, while energy resources are greatly saved, outlet water quality indexes of the ammonia nitrogen reach standards, and total nitrogen is removed very well.
Description
Technical field
The invention belongs to water technology field, be specifically related to a kind of except nitrogen biofiltration device and in the application of processing in micro-polluted source water.
Background technology
Micro-polluted source water refers to the source water from the beginning that is subject to light contamination.China's surface water pollution situation is more serious at present, and drinking water source is subject to the pollution of all kinds of nitrogens mostly, wherein outstanding with the form of ammonia nitrogen.In former water, higher ammonia nitrogen concentration is indicating that water body is suffering to pollute.Ammonia nitrogen in tap water may cause the nitrite problem of pipe network tip and smell taste problem, thereby affects drinking water quality and HUMAN HEALTH.Use comparatively general tap water ammonia nitrogen treatment technology to mainly contain biological process, Physical and chemical method both at home and abroad.Wherein, the not climate condition impact of ion exchange method treatment effect, but exchanger needs regeneration, processing costs is increased greatly, therefore can not be used widely.Biologic treating technique enjoys favor at home and abroad because not producing by product (ammonia nitrogen is completely converted as nitrogen under microbial process).But the processing efficiency of traditional biological method (as biological filter, bio-contact oxidation etc.) is easy to be subject to the impact of various processing condition (as C/N, pH, dissolved oxygen, temperature etc.).In order to improve the removal efficiency of ammonia nitrogen, by ion exchange method and biological process coupling to bring into play both advantages simultaneously.
Zeolite is a kind of well ion-exchange material, not only has good adsorptivity and ion exchangeable, and is well suited for microbial growth breeding.Therefore, the carrier using natural zeolite as BAF has much prospect for the treatment of the ammonia nitrogen in water body.This method be by sludge seeding in natural zeolite biofilter material, strengthen biofilm, after microbial film maturation, under the condition of aeration, the ammonia nitrogen in water is carried out to absorption degradation.In recent years, there is scholar by the removal of ammonia nitrogen in the water bodys such as this method application and sanitary sewage, textile waste, landscape water, and obtained good effect.Meanwhile, also there is scholar this method to be borrowed in to the processing of drinking water resource ammonia nitrogen.Have much for the treatment of the bioprocess technology of drinking water source ammonia nitrogen processing at present, as natural zeolite BAF, active zeolite biological filter, low-density zeolite BAF etc., widely used is natural zeolite biological aerated filter process.
Natural zeolite BAF is using natural zeolite as filter tank bio-carrier, gets active sludge or bed mud in river and carries out bacterization biofilm, obtains the microbial film containing multiple biology, under the condition of omnidistance aeration to water in ammonia nitrogen process.This method can be well nitrite nitrogen and nitric nitrogen by mineralized nitrogen, and ammonia nitrogen concentration in water is reduced greatly.But, in natural zeolite hole and passage as bio-carrier, conventionally by some tradable positively charged ion K
+, Na
+, Ca
2+, Mg
2+, Sr
2+stop up with water molecules and other impurity, hole and channel connection degree poor.This has reduced the absorption property of natural zeolite to ammonia nitrogen; Secondly, this method, using mud as biogenic, is inevitably introduced multiple-microorganism, not only can make heterotrophic microorganism and digestion flora (particularly denitrifying bacteria) compete limited organism, reduce ammonia nitrogen degradation efficiency, also can increase the risk that harmful microorganism occurs in tap water; The more important thing is, this technique is not considered the removal of total nitrogen, adopts omnidistance aeration in technique, and too high dissolved oxygen has suppressed the degraded of denitrifying bacteria to nitric nitrogen, thereby can not remove total nitrogen.Therefore,, after micro-pollution ammonia nitrogen water source being processed by the method, do not eliminate the harm of total nitrogen to HUMAN HEALTH completely.
Active zeolite biological filter and low-density zeolite BAF are all that the bio-carrier of natural zeolite biological filter is improved, though improve the removal efficiency of ammonia nitrogen, but still not using the removal efficiency of total nitrogen as research object.In addition, existing for the treatment of in drinking water source ammonia nitrogen processing method, although ammonia nitrogen conversion fast and nitrite nitrogen and nitrate nitrogen, ammonia nitrogen concentration in water is reduced greatly, but its nitrite nitrogen changing into is only the real killer of HUMAN HEALTH, and nitrate can be reduced into nitrite in stomach and saliva, when mankind's excess intake nitrite can bring out methemoglobinemia and cancer of the stomach, HUMAN HEALTH is worked the mischief, therefore only ammonia nitrogen concentration reduction does not tackle the problem at its root.Drinking Water has organism, ammonia nitrogen concentration containing low, water quality requirement high, want ammonia nitrogen in drinking water sources water finally to degrade, also need the techniques such as bio-carrier, inoculation biogenic and dissolved oxygen control to improve, in biological filter, realize high efficiency synchronous nitration denitrification.
Summary of the invention
For solving the shortcoming and defect part of prior art, it is a kind of except nitrogen biofiltration device that primary and foremost purpose of the present invention is to provide.
Another object of the present invention is to provide above-mentioned except nitrogen biofiltration device is in the application of processing in micro-polluted source water.
For achieving the above object, the present invention adopts following technical scheme:
A kind of except nitrogen biofiltration device, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.
Preferably, the described biological filter bed of material obtains by following preparation method:
(1) mixing solutions that the natural zeolite that is 2～5mm by particle diameter is placed in sodium chloride solution and hydrochloric acid soaks 10～24h, and then water rinses several times, then in 150～250 ℃ of roasting 5～24h, obtains composite modified zeolite;
(2) composite modified zeolite step (1) being obtained is cooled to room temperature and is placed in filter post, obtains modified zeolite filter post, then combination bacterium is seeded to modified zeolite filter post, and static cultivation 5～10 days, obtains the described biological filter bed of material.
Preferred, the soak time described in step (1) is 24h; Described maturing temperature is 200 ℃, and roasting time is 8h.
Preferred, the sodium-chlor described in step (1) in natural zeolite, sodium chloride solution and the mass ratio of hydrochloric acid are 20:4:2～20:2:1.
Preferred, described in step (1), the concentration of sodium chloride solution is 1～3mol/L, and the concentration of hydrochloric acid is 0.5～1.5mol/L.
Most preferred, described in step (1), the concentration of sodium chloride solution is 2mol/L, and the concentration of hydrochloric acid is 0.5mol/L.
Preferred, the mass ratio that combines bacterium and composite modified zeolite described in step (2) is 1:1000～1:3000; The described static cultivation time is 5 days.
Preferred, the combination bacterium described in step (2) is ammonia nitriding bacterium, nitrobacteria and denitrifying bacterium.
Above-mentioned except nitrogen biofiltration device is in the application of processing in micro-polluted source water, comprise the following steps:
(1) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 0.5～1.0m
3/ (m
2h);
(2) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
Preferably, described micro-polluted source water refers to that ammonia nitrogen concentration is 2～8mg/L, and nitrite nitrogen concentration is 0～0.2mg/L, the drinking water resource that nitrate is 0.5～2.5mg/L.
Principle of the present invention is: the present invention soaks rear modification by calcination by natural zeolite with sodium-chlor and hydrochloric acid mixed solution, utilize hydrochloric acid and sodium-chlor mixing solutions that some impurity in zeolite cavity are dissolved, zeolite hole and duct are dredged, utilize the sodium ion in sodium-chlor that the metal ion such as calcium, magnesium in zeolite is cemented out simultaneously, widen the duct of zeolite; Finally remove the impurity such as the water molecules in zeolite hole and duct by roasting, make duct unimpeded.The present invention is directly seeded to modified zeolite (filtrate) filter tank using combination bacterium as biogenic be to organic competition, to increase the cell density of combination bacterium in filter tank in order to reduce other microorganisms in combination bacterium and water body, realizes the fast degradation to nitrogen.The present invention, in the operational process of biological filter, does not need to carry out aeration, and by all kinds of nitrogens in micro-polluted source water, by the simultaneous nitrification and denitrification of combination bacterium, final rapid conversion is nitrogen, and nitrogen problem is really resolved.
Compared with prior art, the present invention has the following advantages and beneficial effect:
(1) in the present invention, natural zeolite is after composite modified, and specific surface area and aperture all increase that (natural zeolite specific surface area and aperture are respectively 21.25m
2/ g, 2.1nm, composite modified zeolite is 33.53m
2/ g, 3.6nm), can not only provide more appendix area for microorganism, and greatly improve its loading capacity and adsorption rate to ammonia nitrogen, can be rapidly the ammonia nitrogen of trace in water and organism be enriched on composite modified Zeolite-bio carrier as bacteriotrophy material by degradation by bacteria.
(2) the present invention inoculates as biogenic with pure combination bacterium except nitrogen biofiltration device, can in the short period of time, form highdensity nitrifying bacteria community microbial film on modified zeolite surface; Operation is convenient with management, not introducing harmful microbe simultaneously, has increased the bacterial density of nitrifier and denitrifying bacteria, has not only ensured water outlet biological safety, and has improved ability and the speed of nitrogen compound in biological degradation water.
(3) the composite modified zeolite that the present invention removes in nitrogen biofiltration device can pass through fast enriching ammonia nitrogen and organism, improve nitrifying bacteria community metabolism desired nutritional material concentration, shorten the bio-film colonization time, improve nitrification and denitrification speed, in the short period of time, realized high efficiency synchronous nitration denitrification.
(4) of the present invention except nitrogen biofiltration device, in the degradation process of ammonia nitrogen, without aeration, can realize simultaneous nitrification and denitrification, make ammonia nitrogen finally be converted into nitrogen, in save energy greatly, guarantee that ammonia nitrogen effluent quality index is up to standard, total nitrogen also obtains fine removal.Compared with BAF, not only greatly saved the energy, and significantly improved the removal effect of total nitrogen in water, improved tap water water quality, ensured HUMAN HEALTH.
Accompanying drawing explanation
Fig. 1 is that the present invention removes nitrogen biofiltration device artwork.
Fig. 2 is comparative example 4 biological aerated filter process figure.
Fig. 3 is the SEM figure of natural zeolite.
Fig. 4 is the SEM figure of the composite modified zeolite prepared of embodiment 1.
Fig. 5 is the SEM figure of the composite modified Zeolite-bio filtrate prepared of embodiment 1.
Fig. 6 is the XRD figure of the composite modified zeolite prepared of natural zeolite and embodiment 1.
Fig. 7 is the Static Adsorption curve of the composite modified zeolite prepared of natural zeolite and embodiment 1.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited to this.
Embodiment 1
Except nitrogen biofiltration device is in an application of processing in micro-polluted source water, comprise the following steps:
(1) except nitrogen biofiltration device
A kind of except nitrogen biofiltration device, as shown in Figure 1, comprise upward flow filter post 8, inlet flume 1, water inlet pipe 3, rising pipe 6 and effluent collector 7, in described upward flow filter post 8, be provided with successively supporting plate 4 and the biological filter bed of material 5 from bottom to top; Described upward flow filter post 8 lower ends are connected with inlet flume 1 by water inlet pipe 3, and described water inlet pipe 3 is positioned at the below of supporting plate 4; Described upward flow filter post 8 upper ends are connected with effluent collector 7 by rising pipe 6, and described rising pipe 6 is positioned at the biological filter bed of material 5 tops; Described water inlet pipe 3 is connected with constant flow pump 2.
Wherein, the described biological filter bed of material 5 obtains by following preparation method:
(1) get 1 mass parts natural zeolite, water rinses for several times, remove soluble impurity, then be placed in the sodium chloride solution of 1 mass parts 2mol/L and the hydrochloric acid mixed solution of 1 mass parts 0.5mol/L, soak 24h, the sodium-chlor in natural zeolite, sodium chloride solution and the mass ratio of hydrochloric acid are 20:4:2; Then water rinses for several times, then is placed in the inherent 200 ℃ of roasting 8h of retort furnace, obtains composite modified zeolite 1;
The composite modified zeolite 1 of 1 mass parts is placed in to the micro-polluted source water containing 10mg/L ammonia nitrogen, carries out static shaking table adsorption test, 25 ℃ of temperature, rotating speed 120r/min, gets supernatant liquor and measures ammonia nitrogen concentration after 24h, and result is as shown in table 1;
(2) the composite modified zeolite 11 mass parts step (1) being obtained is placed in filter post, obtains modified zeolite filter post, then combination bacterium is seeded to modified zeolite filter post, and static cultivation 5 days, obtains the described biological filter bed of material 5;
The mass ratio of described combination bacterium and composite modified zeolite is 1:1000; Described combination bacterium is ammonia nitriding bacterium, nitrobacteria and denitrifying bacterium.
(2) process micro-polluted source water
(a) open constant flow pump 2, water inlet pipe 3 and rising pipe 6, the micro-polluted source water in inlet flume 1 enters upward flow filter post 8 by water inlet pipe 3; Regulating flooding velocity by constant flow pump 2 is 0.5m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 6mg/L;
(b) micro-polluted source water is through supporting plate 4 and the biological filter bed of material 5, and the biological filter bed of material 5 contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector 7 through rising pipe 6.
The present embodiment water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 2.
Embodiment 2
Except nitrogen biofiltration device is in an application of processing in micro-polluted source water, comprise the following steps:
(1) except nitrogen biofiltration device
A kind of except nitrogen biofiltration device, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.Wherein, the described biological filter bed of material obtains by following preparation method:
(1) get 1 mass parts natural zeolite, water rinses for several times, remove soluble impurity, then be placed in the sodium chloride solution of 1 mass parts 2mol/L and the hydrochloric acid mixed solution of 1 mass parts 0.5mol/L, soak 24h, the sodium-chlor in natural zeolite, sodium chloride solution and the mass ratio of hydrochloric acid are 20:2:1.Then water rinses for several times, then is placed in the inherent 200 ℃ of roasting 8h of retort furnace, obtains composite modified zeolite 2.
The composite modified zeolite 2 of 1 mass parts is placed in to the micro-polluted source water containing 10mg/L ammonia nitrogen, carries out static shaking table adsorption test, 25 ℃ of temperature, rotating speed 120r/min, gets supernatant liquor and measures ammonia nitrogen concentration after 24h, and result is as shown in table 1;
(2) the composite modified zeolite 21 mass parts step (1) being obtained is placed in filter post, obtains modified zeolite filter post, then combination bacterium is seeded to modified zeolite filter post, and static cultivation 5 days, obtains the described biological filter bed of material;
The mass ratio of described combination bacterium and composite modified zeolite is 1:3000; Described combination bacterium is ammonia nitriding bacterium, nitrobacteria and denitrifying bacterium.
(2) process micro-polluted source water
(a) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 1.0m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 6mg/L;
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
The present embodiment water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 2.
The variation of process operation Inlet and outlet water ammonia nitrogen, nitrite nitrogen, nitric nitrogen after 5 days of pressing the present embodiment is as shown in table 3.
Except nitrogen biofiltration device is in an application of processing in micro-polluted source water, comprise the following steps:
(1) except nitrogen biofiltration device
A kind of except nitrogen biofiltration device, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.Wherein, the preparation method of the described biological filter bed of material is with embodiment 1;
(2) process micro-polluted source water
(a) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 1.0m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 2mg/L;
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
The present embodiment water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 4.
Except nitrogen biofiltration device is in an application of processing in micro-polluted source water, comprise the following steps:
(1) except nitrogen biofiltration device
A kind of except nitrogen biofiltration device, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.Wherein, the preparation method of the described biological filter bed of material is with embodiment 1;
(2) process micro-polluted source water
(a) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 1.0m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 5mg/L;
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
The present embodiment water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 4.
Embodiment 5
Except nitrogen biofiltration device is in an application of processing in micro-polluted source water, comprise the following steps:
(1) except nitrogen biofiltration device
A kind of except nitrogen biofiltration device, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.Wherein, the preparation method of the described biological filter bed of material is with embodiment 1;
(2) process micro-polluted source water
(a) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 1.0m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 8mg/L;
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
The present embodiment water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 4.
Comparative example 1
The natural zeolite of getting 1 mass parts is placed in the micro-polluted source water containing 10mg/L ammonia nitrogen, carries out static shaking table adsorption test, 25 ℃ of temperature, and rotating speed 120r/min, gets supernatant liquor and measures ammonia nitrogen concentration after 24h, and result is as shown in table 1.
Comparative example 2
Prepare sodium-chlor modified zeolite: get 1 mass parts natural zeolite, water rinses for several times, removes soluble impurity, then be placed in the sodium chloride solution of 1 mass parts 2mol/L, soak 24h, then water rinses for several times, be placed in again the inherent 200 ℃ of roasting 8h of retort furnace, obtain sodium-chlor modified zeolite.
1 mass parts sodium-chlor modified zeolite is placed in to the micro-polluted source water containing 10mg/L ammonia nitrogen, carries out static shaking table adsorption test, 25 ℃ of temperature, rotating speed 120r/min, gets supernatant liquor and measures ammonia nitrogen concentration after 24h, and result is as shown in table 1.
Comparative example 3
Prepare hydrochloric Acid Modification zeolite: get 3 mass parts natural zeolites, water rinses for several times, removes soluble impurity, then be placed in the hydrochloric acid of 1 mass parts 0.5mol/L, soak 24h, then water rinses for several times, be placed in again the inherent 200 ℃ of roasting 8h of retort furnace, obtain hydrochloric Acid Modification zeolite.
1 mass parts hydrochloric Acid Modification zeolite is placed in to the micro-polluted source water containing 10mg/L ammonia nitrogen, carries out static shaking table adsorption test, 25 ℃ of temperature, rotating speed 120r/min, gets supernatant liquor and measures ammonia nitrogen concentration after 24h, and result is as shown in table 1.
Comparative example 4
Composite modified zeolite BAF, in an application of processing in micro-polluted source water, comprises the following steps:
(1) composite modified zeolite BAF
Composite modified zeolite BAF, as shown in Figure 2, comprise upward flow filter post 9, inlet flume 10, water inlet pipe 14, rising pipe 16, effluent collector 11 and air pump 15, in described upward flow filter post 9, be provided with successively supporting plate 12 and the biological filter bed of material 13 from bottom to top; Described upward flow filter post 9 lower ends are connected with inlet flume 10 by water inlet pipe 14, and described water inlet pipe 14 is positioned at the below of supporting plate 12; Described upward flow filter post 9 upper ends are connected with effluent collector 11 by rising pipe 16, and described rising pipe 16 is positioned at the biological filter bed of material 13 tops; Described water inlet pipe 14 is connected with constant flow pump 17; Described air pump 15 is connected with upward flow filter post 9 lower ends.Wherein, the preparation method of the described biological filter bed of material 13 is with embodiment 1;
(2) process micro-polluted source water
(a) open constant flow pump 17, air pump 15, water inlet pipe 14 and rising pipe 16, the micro-polluted source water in inlet flume 10 enters upward flow filter post 9 by water inlet pipe 14; Regulating flooding velocity by constant flow pump 17 is 0.5m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 6mg/L; Pass into air by air pump 15; (flow that air passes into adopt the water surface can just emerge the minimum airshed of bubble)
(b) micro-polluted source water is through supporting plate 12 and the biological filter bed of material 13, and the biological filter bed of material 13 contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector 11 through rising pipe 16.
This comparative example water outlet ammonia nitrogen concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 2.
Comparative example 5
Composite modified zeolite BAF, in an application of processing in micro-polluted source water, comprises the following steps:
(1) composite modified zeolite BAF
Composite modified zeolite BAF, comprises upward flow filter post, inlet flume, water inlet pipe, rising pipe, effluent collector and air pump, in described upward flow filter post, is provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump; Described air pump is connected with upward flow filter post lower end.Wherein, the preparation method of the described biological filter bed of material is with embodiment 2;
(2) process micro-polluted source water
(a) open constant flow pump, air pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 1.0m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 6mg/L; Pass into air by air pump; (flow that air passes into adopt the water surface can just emerge the minimum airshed of bubble)
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
This comparative example water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 2.
According to this comparative example process operation, after 5 days, the variation of Inlet and outlet water ammonia nitrogen, nitrite nitrogen, nitric nitrogen is as shown in table 3.
Comparative example 6
Composite modified zeolite BAF, in an application of processing in micro-polluted source water, comprises the following steps:
(1) composite modified zeolite BAF
Composite modified zeolite BAF, comprises upward flow filter post, inlet flume, water inlet pipe, rising pipe, effluent collector and air pump, in described upward flow filter post, is provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump; Described air pump is connected with upward flow filter post lower end.Wherein, the preparation method of the described biological filter bed of material is with embodiment 1;
(2) process micro-polluted source water
(a) open constant flow pump, air pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Adjusting flooding velocity is 1.1m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 6mg/L; Pass into air by air pump; (flow that air passes into adopt the water surface can just emerge the minimum airshed of bubble)
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
This comparative example water outlet ammonia nitrogen concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 2.
Comparative example 7
Except nitrogen biofiltration device is in an application of processing in micro-polluted source water, comprise the following steps:
(1) except nitrogen biofiltration device
A kind of except nitrogen biofiltration device, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.Wherein, the preparation method of the described biological filter bed of material is with embodiment 1;
(2) process micro-polluted source water
(a) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 1.1m
3/ (m
2h); In micro-polluted source water, ammonia nitrogen concentration is 6mg/L;
(b) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
This comparative example water outlet ammonia nitrogen concentration concentration, ammonia nitrogen and total nitrogen average removal rate are as shown in table 2.
The composite modified Zeolite-bio of embodiment 1 gained, the modified zeolite of comparative example 2-3 and the natural zeolite of comparative example 1 are carried out to structure and performance test:
(1) surface tissue
Natural zeolite, composite modified zeolite and composite modified Zeolite-bio filtrate are scanned by XL30ESEM type scanning electronic microscope (Dutch PHILIPS Co.) the SEM figure that Fig. 3 is natural zeolite; Fig. 4 is the SEM figure of the composite modified zeolite prepared of embodiment 1; Fig. 5 is the SEM figure of the composite modified Zeolite-bio filtrate prepared of embodiment 1; From Fig. 3 to Fig. 5, natural zeolite surface opposed flattened is closely knit; Modified zeolite surface roughen, aperture increase; The load of composite modified Zeolite-bio filter material surface a large amount of combination bacterium.
(2) crystalline structure
The crystalline structure of the composite modified zeolite of with MSALXD2 type XRD determining instrument test being prepared by natural zeolite and embodiment 1, result as shown in Figure 6.As can be seen from FIG., the composition of composite modified zeolite and natural zeolite is basic identical, but calcium ion in natural zeolite duct and hole cemented out by the sodium ion in solution, and composite modified zeolite is changed compared with natural zeolite Partial Feature peak intensity.
(3) Static Adsorption of zeolite to ammonia nitrogen
Static Adsorption: get composite modified zeolite prepared by 1 mass parts natural zeolite and 1 mass parts embodiment 1 and be placed in respectively the micro-polluted source water containing 10mg/L ammonia nitrogen, carry out static shaking table adsorption test, 25 ℃ of temperature, rotating speed 120r/min, Static Adsorption curve is as shown in Figure 7.Result shows, composite modifiedly can accelerate the adsorption rate of zeolite to ammonia nitrogen, and the equilibrium adsorption time of natural zeolite is 12h, and the equilibrium adsorption time of composite modified zeolite is 4h.
The modified zeolite of table 1 natural zeolite and embodiment 1, comparative example 2 to 3 is removed ammonia nitrogen effect
As shown in Table 1, use hydrochloric acid, sodium-chlor and the compound ammonia nitrogen absorption capacity that all can increase zeolite to natural zeolite modification thereof, wherein the present invention uses sodium chloride solution and the composite modified adsorption effect the best to ammonia nitrogen of hydrochloric acid, and ammonia nitrogen absorption capacity is up to 0.96mg/g.
The removal result of table 2 embodiment 1 to 2 and 4 to 7 pairs of ammonia nitrogens of comparative example and total nitrogen
| ? | Influent ammonium concentration | Water outlet ammonia nitrogen concentration | Ammonia nitrogen average removal rate | Total nitrogen average removal rate |
| Embodiment 1 | 6mg/L | 0.15mg/L | 96.54% | 90.03% |
| Embodiment 2 | 6mg/L | 0.28mg/L | 98.00% | 86.83% |
| Comparative example 4 | 6mg/L | 0.32mg/L | 94.09% | 62.16% |
| Comparative example 5 | 6mg/L | 0.37mg/L | 96.13% | 46.29% |
| Comparative example 6 | 6mg/L | 0.80mg/L | 90.30% | 38.80% |
| Comparative example 7 | 6mg/L | 0.63mg/L | 91.81% | 64.17% |
As shown in Table 2, under identical flooding velocity, compared to existing aeration system, the present invention not technique of aeration is more conducive to the removal of ammonia nitrogen and total nitrogen in water, is particularly conducive to the removal of total nitrogen.In addition, when flow is 0.5m
3/ (m
2and 1.0m h)
3/ (m
2h) time, under aeration condition, water outlet ammonia nitrogen concentration all can not meet tap water ammonia nitrogen water quality index request (<0.5mg/L), when flow is 1.1m
3/ (m
2h) time, water outlet ammonia nitrogen concentration is greater than 0.5mg/L, can not meet Indicator for Drinking Water Quality.Therefore, the present invention is flow 0.5～1.0m except nitrogen biofiltration device moves top condition
3/ (m
2h) and not aeration.
The process operation of table 3 embodiment 2 and comparative example 5 after 5 days to various nitrogen removal effects
As shown in Table 3, aeration and aeration is not little to ammonia nitrogen removal influential effect in short period of time, but water outlet nitrite nitrogen and nitric nitrogen all have obvious accumulation under aeration condition, nitrous concentration has exceeded the requirement (<0.5mg/L) to nitrite nitrogen in Drinking Water in China water quality.And not under aeration condition, nitrite nitrogen and nitric nitrogen go out water concentration all lower than influent concentration.This be because, the main nitration reaction that occurs in aerating system, nitration reaction can produce proton, and pH is declined, and is unfavorable for that conversely nitration reaction carries out, thereby makes the ammonia nitrogen that accumulates in zeolite more and more, a little less than the adsorptive power of ammonia nitrogen is also just turned gradually; On the contrary, in system, nitrification and denitrification does not all occur when aeration, and anti-nitration reaction can make up the basicity of nitration reaction, maintains suitable pH environment, is conducive to the long-time running of system.
3 to 5 pairs of ammonia nitrogens of table 4 embodiment and total nitrogen removal effect
| ? | Influent ammonium concentration | Water outlet ammonia nitrogen concentration | Ammonia nitrogen average removal rate | Total nitrogen average |
| Embodiment | ||||
| 3 | 2mg/L | 0.16mg/L | 89.77% | 80.11 |
| Embodiment | ||||
| 4 | 5mg/L | 0.05mg/L | 98.99% | 88.77% |
| Embodiment 5 | 8mg/L | 0.41mg/L | 94.50% | 83.23% |
The demonstration of table 4 result, under different influent ammonium concentrations, after the present invention processes except nitrogen biofiltration device, water outlet ammonia nitrogen concentration all can meet the requirement of tap water ammonia nitrogen water quality index.
Above-described embodiment is preferably embodiment of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present invention and principle, substitutes, combination, simplify; all should be equivalent substitute mode, within being included in protection scope of the present invention.
Claims (10)
1. except a nitrogen biofiltration device, it is characterized in that, comprise upward flow filter post, inlet flume, water inlet pipe, rising pipe and effluent collector, in described upward flow filter post, be provided with successively supporting plate and the biological filter bed of material from bottom to top; Described upward flow filter post lower end is connected with inlet flume by water inlet pipe, and described water inlet pipe is positioned at the below of supporting plate; Described upward flow filter post upper end is connected with effluent collector by rising pipe, and described rising pipe is positioned at biological filter bed of material top; Described water inlet pipe is connected with constant flow pump.
2. the nitrogen biofiltration device that removes according to claim 1, is characterized in that, the described biological filter bed of material obtains by following preparation method:
(1) natural zeolite that is 2～5mm by particle diameter is placed in sodium chloride solution and hydrochloric acid mixed solution soaks 10～24h, and then water rinses several times, then in 150～250 ℃ of roasting 5～24h, obtains composite modified zeolite;
(2) composite modified zeolite step (1) being obtained is cooled to room temperature and is placed in filter post, obtains modified zeolite filter post, then combination bacterium is seeded to modified zeolite filter post, and static cultivation 5～10 days, obtains the described biological filter bed of material.
3. the nitrogen biofiltration device that removes according to claim 2, is characterized in that, the soak time described in step (1) is 24h; Described maturing temperature is 200 ℃, and roasting time is 8h.
4. the nitrogen biofiltration device that removes according to claim 2, is characterized in that, the sodium-chlor described in step (1) in natural zeolite, sodium chloride solution and the mass ratio of hydrochloric acid are 20:4:2～20:2:1.
5. the nitrogen biofiltration device that removes according to claim 2, is characterized in that, described in step (1), the concentration of sodium chloride solution is 1～3mol/L, and the concentration of hydrochloric acid is 0.5～1.5mol/L.
6. the nitrogen biofiltration device that removes according to claim 5, is characterized in that, described in step (1), the concentration of sodium chloride solution is 2mol/L, and the concentration of hydrochloric acid is 0.5mol/L.
7. the nitrogen biofiltration device that removes according to claim 2, is characterized in that, the static cultivation time described in step (2) is 5 days.
8. the nitrogen biofiltration device that removes according to claim 2, is characterized in that, the mass ratio that combines bacterium and composite modified zeolite described in step (2) is 1:1000～1:3000; Described combination bacterium is ammonia nitriding bacterium, nitrobacteria and denitrifying bacterium.
Described in claim 1～8 any one except nitrogen biofiltration device is in the application of processing in micro-polluted source water, it is characterized in that, comprise the following steps:
(1) open constant flow pump, water inlet pipe and rising pipe, the micro-polluted source water in inlet flume enters upward flow filter post by water inlet pipe; Regulating flooding velocity by constant flow pump is 0.5～1.0m
3/ (m
2h);
(2) micro-polluted source water is through supporting plate and the biological filter bed of material, and the biological filter bed of material contacts with micro-polluted source water, removes ammonia nitrogen; The water of removing after ammonia nitrogen enters effluent collector through rising pipe.
10. application according to claim 9, is characterized in that, described micro-polluted source water refers to that ammonia nitrogen concentration is 2～8mg/L, and nitrite nitrogen concentration is 0～0.2mg/L, the drinking water resource that nitrate is 0.5～2.5mg/L.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106587407A (en) * | 2016-12-02 | 2017-04-26 | 常州大学 | Method for removing ammonia nitrogen by combined use of acid-modified zeolite and film |
| CN113511728A (en) * | 2021-07-26 | 2021-10-19 | 河北地势坤环保工程有限公司 | Constructed wetland denitrification system and sewage denitrification method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19806938A1 (en) * | 1998-02-19 | 1999-08-26 | Philipp Mueller Gmbh | Stationary bed reactor for denitrification of water, used in sewage works with biological unit |
| CN1865160A (en) * | 2005-05-20 | 2006-11-22 | 中国科学院大连化学物理研究所 | Use of modified zeolite in treating waste water of shrimp breeding |
| CN101618910A (en) * | 2009-08-14 | 2010-01-06 | 东华大学 | Process and device of novel biological aerated filter for pretreating micro-polluted source water |
| CN101774703A (en) * | 2010-03-17 | 2010-07-14 | 上海交通大学 | Method for depriving nitrogen nutritive salt in surface water |
| CN202576084U (en) * | 2012-03-29 | 2012-12-05 | 江苏商达水务有限公司 | Rural sewage denitrification device |
| CN102992437A (en) * | 2012-11-21 | 2013-03-27 | 中国核电工程有限公司 | Device, structure and process for processing ammonia-nitrogen sewage by aeration zeolite fluidized bed |
-
2014
- 2014-03-31 CN CN201410127269.6A patent/CN103848508B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19806938A1 (en) * | 1998-02-19 | 1999-08-26 | Philipp Mueller Gmbh | Stationary bed reactor for denitrification of water, used in sewage works with biological unit |
| CN1865160A (en) * | 2005-05-20 | 2006-11-22 | 中国科学院大连化学物理研究所 | Use of modified zeolite in treating waste water of shrimp breeding |
| CN101618910A (en) * | 2009-08-14 | 2010-01-06 | 东华大学 | Process and device of novel biological aerated filter for pretreating micro-polluted source water |
| CN101774703A (en) * | 2010-03-17 | 2010-07-14 | 上海交通大学 | Method for depriving nitrogen nutritive salt in surface water |
| CN202576084U (en) * | 2012-03-29 | 2012-12-05 | 江苏商达水务有限公司 | Rural sewage denitrification device |
| CN102992437A (en) * | 2012-11-21 | 2013-03-27 | 中国核电工程有限公司 | Device, structure and process for processing ammonia-nitrogen sewage by aeration zeolite fluidized bed |
Non-Patent Citations (1)
| Title |
|---|
| 魏丽娜等: "改性沸石结合组合菌去除河水中的氨氮", 《非金属矿》, vol. 32, no. 5, 30 September 2009 (2009-09-30) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106587407A (en) * | 2016-12-02 | 2017-04-26 | 常州大学 | Method for removing ammonia nitrogen by combined use of acid-modified zeolite and film |
| CN113511728A (en) * | 2021-07-26 | 2021-10-19 | 河北地势坤环保工程有限公司 | Constructed wetland denitrification system and sewage denitrification method thereof |
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