CN214360828U

CN214360828U - Sewage treatment device for synchronously removing high-efficiency pollutants and comprehensively recycling pollutants

Info

Publication number: CN214360828U
Application number: CN202021965127.4U
Authority: CN
Inventors: 周振; 王凯冲; 余司颀; 覃阳洁; 袁瑶; 肖凯琦; 安莹; 左艺; 张茂楠; 赵晓丹; 夏庆
Original assignee: Shanghai Electric Power University
Current assignee: Shanghai University of Electric Power; Shanghai Electric Power University; University of Shanghai for Science and Technology
Priority date: 2020-09-10
Filing date: 2020-09-10
Publication date: 2021-10-08
Anticipated expiration: 2030-09-10

Abstract

The utility model relates to a sewage treatment device for synchronously removing high-efficiency pollutants and comprehensively recycling pollutants, which treats anaerobic organisms, ammonia nitrogen ion exchange/regeneration, aerobic deep decarburization and phosphate radical (PO)₄ ^3‑) The ion exchange/regeneration (ComRec) combined process is applied to the main stream sewage treatment to realize the high-efficiency pollutant removal; recovery of hardness ions-biological nitration-electrodialysis concentration-evaporative crystallization and calcium ions (Ca)²⁺) Removal of Magnesium Ammonium Phosphate (MAP) precipitate combinationsThe process is applied to the treatment of side-stream sewage and comprehensively recovers carbon, nitrogen, phosphorus, magnesium and calcium from the sewage. The utility model discloses a stable problem up to standard of pollutant under the high emission standard not only can be solved to technology, can also effectively save the transformation land used of upgrading, more can realize the enrichment recovery of nitrogen phosphorus and other element resources under the low pollutant concentration of town sewage.

Description

Sewage treatment device for synchronously removing high-efficiency pollutants and comprehensively recycling pollutants

Technical Field

The utility model belongs to the technical field of environmental protection and sewage treatment, a synchronous high-efficient pollutant is got rid of and comprehensive resource recovery's sewage treatment plant is related to.

Background

The sewage contains non-insignificant resource potential, such as organic matters, nitrogen and phosphorus, metal elements and the like with considerable content. However, although the conventional sewage treatment processes represented by the activated sludge method can effectively remove pollutants, the recovery of substances and resource recycling in the sewage are ignored. The traditional sewage treatment process converts organic pollutants into CO in an aeration oxygen supply mode₂The organic nitrogen and ammonia Nitrogen (NH) in a reduction state₄ ⁺Oxidation of-N) to Nitrate (NO)₃ ^-) Then converted into nitrogen (N) by anoxic denitrification₂) Nitrogen and phosphorus pollutants are removed in a mode of intensive input of energy and substances. The overall process employs a pollutant removal mode based on excess input of energy and materials, producing large quantities of greenhouse gases and excess sludge. The sewage with high energy consumption, high land occupation and high carbon footprintThe treatment mode is not in accordance with the sustainable development concept under the current global energy crisis and climate change background, and gradually becomes a main bottleneck restricting the development of the sewage treatment industry to circular economy, clean production, energy conservation and consumption reduction.

The recycling of sewage is always a great challenge for town sewage treatment. In recent years, a recycling technology for an end product of an activated sludge process is continuously developed. The research and development of the membrane technology realize the high-quality recycling of secondary effluent, and the Singapore develops a Newater process based on a 'double-membrane method', so that the high-quality recycling of urban sewage and drinking water is realized. Aiming at excess sludge, a great deal of research focuses on improving anaerobic digestion efficiency to realize maximum energy recycling, including pyrohydrolysis, alkali treatment, ultrasonic treatment, ozone pretreatment, efficient co-fermentation of excess sludge and kitchen waste and the like. Aiming at nutrient elements, nitrogen and phosphorus elements in the anaerobic digestion solution of the excess sludge are mainly recovered by a stripping or chemical precipitation method in the prior art. However, most of the existing sewage recycling technologies only focus on local recycling of end products (secondary effluent, excess sludge and anaerobic digestion solution) of an activated sludge process, do not perform system transformation on a sewage treatment process from the perspective of sustainable idea, do not solve the problems of carbon source loss caused by aerobic metabolism of microorganisms and unbalance of nitrogen and phosphorus ratio in a chemical precipitation method, and although the sewage recycling can be realized to a certain degree, have a certain gap from the comprehensive recycling of the sewage.

At present, experts and scholars at home and abroad are exploring the best way for comprehensively recycling sewage. According to the characteristics of sewage resource, the method mainly comprises the following classifications: (1) the representative technology is the water process of singapore, paying attention to the resource recycling of high-quality water and even pursuing the limit water quality reaching the drinking standard. The process successfully realizes the recycling of high-quality water at the drinking water level by coupling a membrane technology on the basis of the traditional aerobic activated sludge and utilizing a microfiltration-reverse osmosis double-membrane method. However, the technical route takes water recycling as a primary target, abandons the recycling of nitrogen and phosphorus elements while having high energy consumption, and does not change the limitation that the traditional sewage treatment mode pursues comprehensive resource utilization. (2) The sewage treatment process is energy-saving and consumption-reducing based on anaerobic ammonia oxidation, and the representative technology is A-section biological adsorption and mainstream anaerobic ammonia oxidation process. The process realizes the anaerobic capacity of the sludge and reduces the energy consumption by improving the sludge yield and autotrophic mainstream anaerobic ammonium oxidation denitrification, effectively improves the current situation of high energy consumption of a sewage treatment plant, and even realizes positive output of energy. However, the process lacks nitrogen element recycling and is not different from the traditional nitrification/denitrification process. (3) Regarding the utilization of carbon source and organic matter energy in sewage, the representative technology is anaerobic membrane bioreactor (AnMBR). The process combines the anaerobic technology with the membrane technology, can directly utilize the carbon source in the sewage to realize anaerobic capacity, but has limited methane production amount and no nitrogen and phosphorus removal function. (4) The nitrogen and phosphorus elements in the sewage are utilized, and the typical technology is algae cultivation. The algae absorbs nitrogen and phosphorus elements in the sewage through photosynthesis, and the harvested algae is used as feed or biomass fuel for processing. The technology has large occupied area (more than 50 times of the traditional activated sludge method), and can not meet the conventional discharge standard.

Chinese patent CN110981077A discloses NH based on side stream shortcut nitrification-anaerobic ammonia oxidation process₄ ⁺-N efficient removal systems and methods. The treatment system comprises an ammonia nitrogen ion exchange unit, a heating regeneration unit and a regeneration liquid denitrification module, wherein the ammonia nitrogen ion exchange unit comprises an ammonia nitrogen ion exchange column filled with an ammonia nitrogen ion exchanger, the heating regeneration unit comprises a regeneration liquid storage box and a regeneration liquid water inlet pump which are sequentially connected, the regeneration liquid storage box is connected with a regeneration liquid inlet of the ammonia nitrogen ion exchange column through the regeneration liquid water inlet pump, the regeneration liquid is heated in the regeneration liquid storage box through a sewage source heat pump, the regeneration liquid storage box is also connected with the ammonia nitrogen ion exchange unit and recovers the regeneration liquid flowing out of the ammonia nitrogen ion exchange column, and the regeneration liquid denitrification module is connected with the regeneration liquid storage box of the heating regeneration unit. The utility model adopts the salt solution to regenerate the adsorption material and the NH₄ ⁺Concentrating N into the regeneration liquid and realizing the recycling of the regeneration liquid by means of side stream short-cut nitrification-anaerobic ammonia oxidation, but the short-cut nitrification-anaerobic ammonia oxidation can lead NH in the regeneration liquid to be recycled₄ ⁺Reduction of-N to N₂Nitrogen recovery cannot be achieved.

Chinese patent CN107417047A discloses a device and method for complete denitrification and synchronous phosphorus recovery. The device comprises a municipal sewage raw water tank, an endogenous short-range denitrification/anaerobic ammonia oxidation integrated reactor, an intermediate water tank I, a crystallized phosphorus recovery reactor, a dosing tank, a nitration reactor and an intermediate water tank II. The method comprises the steps that municipal sewage firstly enters an endogenous short-cut denitrification/anaerobic ammonium oxidation integrated reactor, and microorganisms absorb organic matters in raw water and convert the organic matters into phosphorus-accumulating compounds and release a large amount of phosphorus; then, the sewage enters a crystallized phosphorus recovery reactor to realize the recovery of phosphorus; then, the sewage enters a nitration reactor to carry out nitration reaction; and finally, synchronously carrying out endogenous short-cut denitrification, anaerobic ammonium oxidation and denitrifying phosphorus removal reactions in the wastewater in the endogenous short-cut denitrification/anaerobic ammonium oxidation integrated reactor again. The method can realize complete denitrification and phosphorus recovery, not only economically and efficiently treats the sewage, but also fully recovers resources. The utility model realizes the recovery of phosphorus in operation, but the NH in the regenerated liquid can be recovered by short-cut nitrification-anaerobic ammonia oxidation₄ ⁺Reduction of-N to N₂Nitrogen recovery cannot be achieved, and other trace elements cannot be recovered.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a sewage treatment plant and technology that synchronous high-efficient pollutant was got rid of and comprehensive resourceization was retrieved, not only can solve the stable problem up to standard of pollutant under the high emission standard, can also effectively save the upgrading transformation land used, more can realize the enrichment recovery of nitrogen phosphorus and other element resources under the low pollutant concentration of town sewage.

The purpose of the utility model can be realized through the following technical scheme:

on the one hand, the utility model provides a synchronous high-efficient pollutant is got rid of and comprehensive resource recovery's sewage treatment plant, include:

mainstream sewage treatment system: comprises an anaerobic bioreactor, an ammonia nitrogen ion exchange unit, an aerobic bioreactor and a phosphorus ion exchange column which are connected in sequence along the sewage treatment direction through a main stream sewage pipeline;

nitrogen recovery side stream system: the device comprises a magnesium recovery sedimentation tank, a first calcium recovery sedimentation tank, a biological nitrification reactor and a first regeneration liquid storage tank which are sequentially connected with the side part of an ammonia nitrogen ion exchange unit through pipelines, wherein the first regeneration liquid storage tank is also connected with the ammonia nitrogen ion exchange unit in a return way;

phosphorus recovery side stream system: the device comprises a second calcium recovery sedimentation tank, a phosphorus ion exchange column and a second regenerated liquid storage box which are sequentially connected with the side part of the ammonia nitrogen ion exchange unit through pipelines, wherein the second regenerated liquid storage box is also connected with the ammonia nitrogen ion exchange unit in a returning way.

Furthermore, the ammonia nitrogen ion exchange unit comprises a first ammonia nitrogen ion exchange column and a second ammonia nitrogen ion exchange column which are arranged side by side, wherein the first ammonia nitrogen ion exchange column is connected into the nitrogen recovery side flow system, and the second ammonia nitrogen ion exchange column is connected into the phosphorus recovery side flow system.

Further, the first regeneration liquid storage tank is also connected with a sewage source heat pump and is used for heating, and the heating temperature is preferably 15-50 ℃.

Further, the biological nitrification reactor is also provided with a first aeration pump; the aerobic bioreactor is also provided with a second aeration pump.

Further, along the flow direction in the nitrogen recovery side flow system, the first regenerated liquid storage tank is sequentially connected with the electrodialysis module and the evaporation crystallization module, and the electrodialysis module and the evaporation crystallization module are respectively returned and connected with the ammonia nitrogen ion exchange unit.

Furthermore, the electrodialysis module comprises an electrodialysis water inlet valve, an electrodialysis reactor and an electrodialysis fresh water reflux valve which are connected in sequence; the evaporative crystallization module comprises an evaporative crystallization water inlet valve, an evaporative crystallization device and a condensate water reflux valve which are connected in sequence. And the electrodialysis fresh water reflux valve and the condensate water reflux valve are both connected with the ammonia nitrogen ion exchange unit through pipelines.

Further, a magnesium recycling doser and a first calcium recycling doser are respectively arranged on the magnesium recycling sedimentation tank and the first calcium recycling sedimentation tank, and the magnesium recycling doser and the first calcium recycling doser are respectively arranged on the magnesium recycling sedimentation tank and the first calcium recycling sedimentation tankThe second calcium recovery sedimentation tank is provided with a second calcium recovery doser, and the second regenerated liquid storage tank is also respectively connected with a pH adjusting tank and Mg (OH)₂A dosing box.

Further, the anaerobic bioreactor can be one or more of an anaerobic contact digestion tank, an Upflow Anaerobic Sludge Blanket (UASB), an internal circulation anaerobic reactor, an anaerobic granular sludge expanded bed, an AnMBR, an anaerobic fluidized bed and an anaerobic biological rotating disc.

Further, the inoculated sludge in the anaerobic bioreactor can be one or more of excess sludge of urban sewage treatment plants, anaerobic sludge, anaerobic digested sludge and anaerobic granular sludge.

Further, the aerobic bioreactor can be one or a combination process of a Biological Aerated Filter (BAF), a membrane-bioreactor (MBR), an aerobic tank and a secondary sedimentation tank reactor. More preferably, the aerobic bioreactor has a sludge age (SRT) of 5-500 days. More preferably, the Hydraulic Retention Time (HRT) of the aerobic bioreactor is between 0.5 and 48 h.

Further, the sewage to be treated is reclaimed water or secondary effluent water treated by a sewage treatment plant.

Furthermore, the working mode of the phosphorus ion exchange column is an up-flow mode or a vertical flow mode.

On the other hand, the utility model provides a synchronous high-efficient pollutant is got rid of and comprehensive resource recovery's sewage treatment process, its adoption is implemented as above-mentioned sewage treatment plant, and this sewage treatment process includes following step:

(1) feeding the sewage to be treated into an anaerobic biological reactor for anaerobic biodegradation treatment, feeding the treated sewage into an ammonia nitrogen ion exchange unit consisting of a first ammonia nitrogen ion exchange column and a second ammonia nitrogen ion exchange column side by side to remove ammonia nitrogen, then feeding the sewage into an aerobic biological reactor for deep decarburization, and finally removing phosphorus in a phosphorus ion exchange column, namely discharging the sewage;

(2) the regeneration liquid for regenerating the ammonia nitrogen ion exchange unit is divided into two streams, wherein one stream is regeneration liquid I fed from a first regeneration liquid storage tank, the other stream is regeneration liquid II fed from a second regeneration liquid storage tank, the regeneration liquid I is fed into a nitrogen recovery side flow system after regenerating a first ammonia nitrogen ion exchange column, the regeneration liquid I sequentially enters a magnesium recovery sedimentation tank and a first calcium recovery sedimentation tank for hardness ion precipitation recovery, then enters a biological nitrification reactor for nitrification treatment, and then returns to the first regeneration liquid storage tank, one part of the regeneration liquid I in the first regeneration liquid storage tank continuously sequentially flows into an electrodialysis module and an evaporation crystallization module for treatment, a crystallized product is recovered, and the other part of the regeneration liquid I flows back to the first ammonia nitrogen ion exchange column;

(3) the regeneration liquid II is sent into a phosphorus recovery side flow system after regenerating a second ammonia nitrogen ion exchange column, firstly enters a second calcium recovery sedimentation tank for calcium ion precipitation recovery, then enters a phosphorus ion exchange column for completing phosphorus ion regeneration, finally returns to a second regeneration liquid storage tank, and is subjected to pH regulation and Mg (OH) adding in the second regeneration liquid storage tank₂And generating MAP, and realizing synchronous recovery of nitrogen and phosphorus and regeneration of the regeneration liquid II.

Further, in the step (1), the flow rate of the sewage respectively flowing into the first ammonia nitrogen ion exchange column and the second ammonia nitrogen ion exchange column is equal to the flow rate of phosphorus and NH in the sewage₄ ⁺-molar ratio of N.

Further, the ammonia nitrogen ion exchanger used in the first ammonia nitrogen ion exchange column and the second ammonia nitrogen ion exchange column is selected from one or more of natural zeolite, modified zeolite, molecular sieve, fly ash or ion exchange resin. More preferably, the regeneration mode of the ammonia nitrogen ion exchanger can be concurrent regeneration or countercurrent regeneration.

Furthermore, the phosphorus ion exchanger used in the phosphorus ion exchange column is one or more of anion exchange resin, modified zeolite, modified biochar or molecular sieve.

Further, the regeneration liquid I is a mixed solution of one or more of sodium nitrate, potassium nitrate or calcium nitrate, and the concentration of the regeneration liquid I is 0.01-100 g/L;

furthermore, the regeneration liquid II is one or a mixture of more of sodium chloride, potassium chloride, magnesium chloride, sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate, and the concentration of the regeneration liquid II is 0.01-100 g/L.

Further, the empty column residence time (EBCT) of the sewage in the first ammonia nitrogen ion exchange column and the second ammonia nitrogen ion exchange column is 1-600 min;

EBCT of the sewage in the phosphorus ion exchange column is 1-600 min.

Further, the regeneration time of the regeneration liquid I and the regeneration liquid II on the first ammonia nitrogen ion exchange column and the second ammonia nitrogen ion exchange column is 0.1-72 h.

Furthermore, the regeneration time of the regeneration liquid II on the phosphorus ion exchange column is 0.1-72 h.

Further, the pH in the second regeneration liquid storage tank is controlled to be 6.0-12.0.

Further, the calcium removing agent adopted in the first calcium recovery sedimentation tank is one or more of carbonate and bicarbonate, and the calcium recovery agent adopted in the second calcium recovery sedimentation tank is one or more of carbonate, bicarbonate and polyphosphate.

Further, the magnesium recovery agent adopted in the magnesium recovery sedimentation tank is one or more of sodium hydroxide, lime, calcium hydroxide, carbonate and bicarbonate.

Further, the biological nitration reactor can be one or a combination process of MBR, moving bed bio-membrane reactor, aerobic tank + sedimentation tank + membrane pretreatment and BAF. More preferably, the pH value of the inlet water is controlled to be 6.0-10.0, the inlet water temperature is controlled to be 15-40 ℃, and the inlet water NH is controlled₄ ⁺The concentration of N is 25-2000mg/L, and the SRT is 1-500 d. More preferably, the Dissolved Oxygen (DO) of the biological nitrification reactor is controlled to be 0.5-8 mg/L.

Furthermore, HRT of the regeneration liquid to be treated in the biological nitrification reactor is 1-48 h.

Further, the proportion of the regeneration liquid I flowing into the electrodialysis module in the first regeneration liquid storage tank can be adjusted to be 0-100% according to needs.

Further, feed water NO of electrodialysis module₃ ^-The concentration is 200-20000 mg/L.

Further, the HRT of the dilute chamber of the electrodialysis module can be 0.1-24 h; the HRT of the concentration chamber can be 0.1-24 h. Preferably, the electrode compartment electrolyte of the electrodialysis module is one or more of sodium sulfate, potassium sulfate, sodium chloride and potassium chloride.

Further, the ion exchange membrane of the electrodialysis module can be one or more of a homogeneous membrane, a heterogeneous membrane, a bipolar membrane and an electrophoresis electrolysis membrane. The flow rate ratio of the dilute and concentrate chambers can be from 1:1 to 50: 1.

Further, the evaporative crystallization unit can adopt one or more combinations of a mechanical vapor recompression evaporator (MVR), a multi-effect evaporator, a waste water evaporator, a forced circulation evaporator, a continuous crystallization evaporator, a falling film (climbing film) evaporator and a rotary wiped film evaporator.

Further, the reagent for adjusting the pH of the second regeneration liquid storage tank may be one or more of sodium hydroxide, potassium hydroxide, lime, magnesium oxide, sodium carbonate, sodium bicarbonate, magnesium hydroxide, hydrochloric acid, sulfuric acid, and the like.

The utility model provides a combined process based on anaerobic biological treatment-ammonia nitrogen ion exchange/regeneration-aerobic deep decarburization-phosphorus ion exchange/regeneration, which realizes the synchronous high-efficiency removal of sewage pollutants and the comprehensive recycling of substances.

In an anaerobic biological treatment unit (i.e., an anaerobic biological processor), complex organic matters in sewage are degraded by anaerobic biological treatment, and a large amount of methane is produced and recovered. The anaerobic condition of the reaction process can retain NH in the sewage₄ ⁺-N and hydrolysis of organic nitrogen to NH₄ ⁺-N, hydrolysis of phosphorus in organic matter to PO₄ ^3-. The process unit can convert nitrogen in the sewage into NH to the maximum extent₄ ⁺N, provides good conditions for subsequent ammonia nitrogen ion exchange.

In the ion exchange/regeneration unit (mainly ammonia nitrogen ion exchange unit), NH of the effluent of the anaerobic biological unit₄ ⁺N can be removed rapidly, and metal ions such as calcium, magnesium and the like can be trapped. In the regeneration process, the regeneration rate and efficiency are effectively improved through the heating of the sewage source heat pump, and the proper temperature of the regenerated liquid can provide a good environment for the side-stream biological nitrification unit. The regenerated liquid is divided into two paths, and the regenerated liquid I is used for recovering sodium nitrate by nitrationAnd the regenerated liquid II flows into a phosphorus recovery unit. Hardness ions in the regeneration liquid I are converted into precipitates for recycling by adding a precipitator, and Mg (OH) can be effectively recycled₂And CaCO₃And the like. Biological nitrification is carried out to remove NH in positive valence state in the regeneration liquid I to be treated₄ ⁺Conversion to NO in the negative valence state₃ ^-Skillfully accomplish NO₃ ^-Enrichment and avoidance of NH in regeneration liquid I₄ ⁺The regeneration of the ammonia nitrogen ion exchanger I is inhibited, and the recycling of the regeneration liquid I and the high-efficiency regeneration of the ammonia nitrogen ion exchanger I are realized. And a part of the regeneration liquid I flows into the electrodialysis module from the first regeneration liquid storage tank to be concentrated by the nitrate. And (3) leading the fresh room effluent of the electrodialysis module to flow back to the first regeneration liquid storage tank, leading the concentrated water to enter the evaporation crystallization unit, recovering a crystallization product, and realizing nitrogen recovery. Meanwhile, water vapor generated by evaporation crystallization is recovered, and the condensed and liquefied water vapor flows back to the first regeneration liquid storage tank.

The effluent of the ammonia nitrogen ion exchange unit mainly contains soluble COD and a small amount of NH₄ ⁺N, which can be further subjected to deep decarbonization by aerobic biological treatment and nitration of residual NH₄ ⁺-N. Due to COD and NH₄ ⁺the-N load is greatly reduced through anaerobic biological treatment and ammonia nitrogen ion exchange, the HRT required by an aerobic biological treatment unit is greatly reduced, and the occupied area of a sewage treatment process is also reduced.

And finally, removing phosphorus from the effluent of the aerobic biological treatment unit through phosphorus ion exchange/regeneration. After phosphorus removal, regeneration is carried out by using regeneration liquid II due to NH₄ ⁺-N and PO₄ ^3-The regeneration of the regeneration liquid II needs cations and anions respectively, so that the regeneration liquid II can meet the requirements of the regeneration of the cations and the anions by adopting one salt. And the regeneration liquid II enters a side flow treatment system after completing the regeneration of the phosphorus ion exchanger. In a sidestream system, Ca in regeneration liquid II²⁺And recovering the precipitator II by adding calcium to convert into precipitate for recovery. In a second regeneration liquid storage tank, the pH is adjusted and recovered Mg (OH) is added₂And generating MAP to realize synchronous recovery of nitrogen and phosphorus. At the same time, the recovery of MAP also reduces NH in the regeneration liquid II₄ ⁺And PO₄ ^3-Concentration of NH in the regeneration liquid II₄ ⁺And PO₄ ^3-The regeneration of the phosphorus ion exchanger and the ammonia nitrogen ion exchanger II (namely the material used by the second ammonia nitrogen ion exchange column) is inhibited, and the reutilization of the regeneration liquid II and the high-efficiency regeneration of the ion exchanger are realized.

The application of the technical route realizes the comprehensive recycling of substances in the sewage and simultaneously realizes the discharge of water pollutants (COD and NH)₄ ⁺The concentration of-N, Total Nitrogen (TN), Total Phosphorus (TP) and the like) can meet the requirements of the class IV water standard of the first grade A emission standard of pollutant emission standard of municipal wastewater treatment plant (GB18918-2002) and even stricter environmental quality standard of surface water (GB 3838-2002). In addition, the process has the advantages of short HRT, small occupied area, high treatment efficiency and the like, and has important practical engineering significance for upgrading and modifying a sewage treatment plant, relieving water eutrophication and comprehensively recycling sewage.

The utility model discloses an in the course of working up, the reaction principle of each processing technology step that involves is as follows:

anaerobic biological treatment unit (i.e. anaerobic bioreactor): anaerobic biological treatment is a multi-stage complex process, and mainly comprises four stages, namely hydrolysis, acidification, acetogenesis and methanation. The methanation stage takes place in the late phase of the anaerobic biological treatment, during which methanogens convert acetic acid (CH)₃COOH) and H₂、 CO₂Separately converted to methane. The sewage can be firstly treated by anaerobic organisms to convert organic matters contained in the sewage into methane, and energy recovery is realized while pollutants are removed; meanwhile, the anaerobic degradation can convert organic nitrogen in the sewage into NH₄ ⁺-N, maximization of NH in wastewater₄ ⁺-the content of N. The reactions in the methanation stage are shown in formulae (1) and (2):

2CH₃COOH→2CH₄↑+2CO₂↑ (1)

4H₂+CO₂→CH₄+2H₂O 4H₂+CO₂→CH₄+2H₂O (2)

ammonia nitrogen ion exchange unit: removing NH in sewage by solid ammonia nitrogen ion exchanger through ion exchange₄ ⁺N, enabling the effluent to meet the requirements of relevant discharge standards, and carrying out ion exchange reaction shown in formula (3):

wherein, B⁺Is surface exchangeable ions of the ammonia nitrogen ion exchanger, A^-Is an ammonia nitrogen ion exchanger structure.

An ammonia nitrogen regeneration unit (regeneration is realized by a regeneration liquid I and a regeneration liquid II which are mainly provided by a first regeneration liquid storage tank and a second regeneration liquid storage tank): the regeneration unit utilizes the positive ions in the regeneration liquid to remove ammonium (NH) on the surface of the ammonia nitrogen ion exchanger₄ ⁺) The ammonia nitrogen ion exchanger is exchanged into the regenerated liquid to realize the regeneration of the ammonia nitrogen ion exchanger, and the sewage source heat pump can be used for heating the regenerated liquid to improve the regeneration rate. The regeneration reaction is shown in formula (4):

wherein, C⁺Is NH₄ ⁺-N cations in the regeneration liquid. The regeneration process is endothermic reaction, and heating the regeneration liquid is beneficial to realizing rapid and efficient regeneration.

In the ammonia nitrogen ion exchange and regeneration (AIR) process, metal ions in the sewage also participate in the process, and finally NH₄ ⁺-N and hardness ion (Mg)²⁺、Ca²⁺) Will be enriched in the regeneration liquid. The utility model discloses the mode of planning through chemical precipitation carries out hardness ion and retrieves, avoids flowing into subsequent processing unit simultaneously, influences nitrogen and retrieves product purity, and retrieves for phosphorus and provides the magnesium source. After the hardness ions are recovered and removed, aiming at high-concentration NH in the regenerated liquid₄ ⁺And (4) recovering nitrogen by adopting a combined process of biological nitrification, electrodialysis concentration and evaporative crystallization. The principle of each unit reaction is as follows.

Hardness ion recovery unit (mainly composed ofThe magnesium recovery sedimentation tank, the first calcium recovery sedimentation tank and the second calcium recovery sedimentation tank are composed of the following components: the unit is divided into two subunits, each of which is Mg²⁺Recovery unit and first Ca²⁺And a recovery unit. By increasing Mg² ⁺Recovering the pH of the unit as Mg (OH)₂Form (2) recovering Mg²⁺. Adding the first Ca to the precipitation agent²⁺Recovery unit with CaCO₃Recovering Ca in the form of²⁺And reducing the pH flowing into the biological nitrification unit while providing alkalinity. See formulas (5), (6) and (7):

Mg²⁺+2OH^-→Mg(OH)₂↓ (5)

biological nitrification unit (mainly comprising biological nitrification reactor): NH is generated by ammonia oxidizing bacteria and nitrifying bacteria₄ ⁺Complete conversion to NO₃ ^-And simultaneously consuming alkalinity, see formulas (8) and (9):

NH₄ ⁺+2O₂+2HCO₃ ^-→NO₃ ^-+2CO₂+3H₂O (8)

biological nitrification is a mature process in town sewage treatment, and NH with positive valence is introduced into a side stream by biological nitrification₄ ⁺Conversion to NO in the negative valence state₃ ^-Avoid NH₄ ⁺The inhibition effect on the regeneration of the ion exchanger is accumulated, the recycling of the regeneration liquid is skillfully realized, and the high regeneration efficiency is maintained.

Electrodialysis concentration unit (i.e. electrodialysis module): selective permeation of NO by anion-cation exchange membrane₃ ^-And metal cations are separated from the regeneration liquid. In the light room, NO₃ ^-And the directional movement of metal cations to regenerate NO in the liquid₃ ^-And the concentration of metal cations is reduced, the concentration chambers respectively realize the concentration of anions and cations, and finally realize the NO in the concentrated solution₃ ^-And (4) enriching.

An evaporation crystallization unit: and introducing the concentrated solution of the electrodialysis concentration unit, evaporating to obtain sodium nitrate crystal salt, and realizing nitrogen recovery.

And the fresh water desalted by electrodialysis and the condensate water of evaporative crystallization flow back to the regenerated liquid storage unit, so that the zero discharge of wastewater of the side flow system is realized.

Phosphorus ion exchange unit (i.e. phosphorus ion exchange column): the solid phosphorus ion exchanger removes phosphorus in the sewage through ion exchange, so that the effluent meets the requirements of relevant discharge standards, and the ion exchange reaction is shown as a formula (10):

A³⁺(D^-)₃+PO₄ ^3-→A³⁺PO₄ ^3-+3D^- (10)

wherein D is^-Is a surface exchangeable ion of a phosphorus ion exchanger, A³⁺Is a phosphorus ion exchanger structure.

A phosphorus regeneration unit: the regeneration unit exchanges phosphorus ions on the surface of the ion exchanger into the regeneration liquid by utilizing anions in the regeneration liquid to realize the regeneration of the phosphorus ion exchanger. The regeneration reaction is shown in formula (11):

A³⁺PO₄ ^3-+3E^-→A³⁺(E^-)₃+PO₄ ^3- (11)

wherein E is^-Is the anion in the phosphorus regeneration liquid.

The utility model discloses the intention adopts the homogeneous regeneration liquid, carries out the synchronous regeneration to phosphorus ion exchanger and partial ammonia nitrogen ion exchanger. Regenerated PO₄ ^3-、NH₄ ⁺And hardness ions will be inAnd enriching in the regeneration liquid. The utility model discloses plan to carry out Ca through chemical precipitation²⁺Recycling, and avoiding influencing the purity of the phosphorus recycled product due to the inflow of the phosphorus into a subsequent processing unit. Reuse of PO in regenerated liquid₄ ^3-、NH₄ ⁺、Mg² ⁺And recovered Mg (OH)₂MAP was generated and recovered. The principle of each unit reaction is as follows.

Second Ca²⁺A recovery unit: adding a precipitating agent to the second Ca²⁺Recovery unit with CaCO₃Recovering Ca in the form of²⁺. See formula (7) for a specific reaction formula.

MAP recovery unit (performed in second regeneration liquid storage tank): to regenerate NH in liquid₄ ⁺As nitrogen source, Mg²⁺And recovered Mg (OH)₂As a magnesium source, MAP was synthesized. See formula (12):

Mg²⁺+PO₄ ^3-+NH₄ ⁺+6H₂O→MgNH₄PO₄·6H₂O (12)

the utility model treats anaerobic organisms, exchanges ammonia nitrogen ions/regenerates, decarbonizes deeply and utilizes phosphate radical (PO)₄ ^3-) The ion exchange/regeneration (ComRec) combined process is applied to the main stream sewage treatment to realize the high-efficiency pollutant removal; recovery of hardness ions-biological nitration-electrodialysis concentration-evaporative crystallization and calcium ions (Ca)²⁺) The combined process of removing-Magnesium Ammonium Phosphate (MAP) precipitate is applied to the treatment of side-stream sewage, and comprehensively recovers carbon, nitrogen, phosphorus, magnesium and calcium from the sewage. The utility model provides a sewage treatment process for synchronously and efficiently removing pollutants and comprehensively recovering resources. The process can solve the problem of stable standard reaching of pollutants under high discharge standard, effectively save the land for upgrading and reconstruction, and can realize enrichment and recovery of nitrogen, phosphorus and other element resources under low pollutant concentration of town sewage.

Compared with the prior art, the utility model has the advantages of it is following:

(1) through mainstream anaerobic biological treatment, the treatment energy consumption is reduced, the methane recovery is realized, and the trend of energy conservation and emission reduction of a sewage treatment plant is met.

(2) In the process of nitrogen recovery, NH in the regeneration liquid is separated by side-stream biological nitrification₄ ⁺Conversion to NO₃ ^-Complete the valence conversion of nitrogen and avoid NH in positive valence state₄ ⁺The inhibition of the regenerated ammonia nitrogen ion exchanger realizes the reutilization of the regenerated liquid and the high-efficiency regeneration of the ammonia nitrogen ion exchanger.

(3) The overall process design of ammonia nitrogen ion exchange/regeneration-biological nitrification-electrodialysis concentration-evaporative crystallization has obvious innovation. Biological nitrification is a mature technology, the nitrate recovery from the side stream by utilizing the biological nitrification is milder, and the operation is easier than that of the existing nitrate production process. By combining ammonia nitrogen ion exchange/regeneration-biological nitrification, the problem that the high-concentration ammonia nitrogen regeneration liquid of the ammonia nitrogen ion exchanger cannot be reused is solved, and electrodialysis on low-concentration NO is avoided₃ ^-The recycling property is not suitable. Meanwhile, the biological nitrification-electrodialysis concentration-evaporative crystallization process is organically coupled, and the high-efficiency nitrogen recovery is realized in the form of nitrate on a side stream. Compared with the traditional biological denitrification and physical and chemical denitrification, the method realizes high-efficiency denitrification by the nitrogen separation and recovery method. Compare with current ammonia nitrogen ion exchange regeneration technology and mainstream recovery ammonia nitrogen technology, the utility model has the advantages of ion exchanger regeneration cost is low, high-efficient nitrogen is retrieved, accords with the theory of recycling economy and sustainable development, is favorable to the cyclic utilization of nitrogen and recycling economy's development.

(4) The regeneration can be matched to the optimum temperature for the nitration by increasing the temperature. The utility model discloses low-quality heat source in the usable sewage promotes regeneration liquid temperature, and this regeneration efficiency that has both helped improving ammonia nitrogen ion exchanger for regeneration rate provides favorable environmental condition for the growth of sidestream nitrobacteria and nitration again, has effectively reduced the sewage treatment energy consumption when improving technology operating efficiency.

(5) The nitrogen recovery side flow system adopts nitrate regeneration, so that the nitrate purity in the solution after the form conversion of nitrogen can be ensured while the regeneration rate and efficiency are ensured, and the economic value of nitrogen recovery is improved. Meanwhile, through proper salinity concentration control, the microbial activity of the sidestream nitrification unit is not inhibited, and the nitrification efficiency can be ensured.

(6) Realizing NO by biological nitrification unit effluent₃ ^-And (4) concentrating a part of effluent by electrodialysis. And (4) the concentrated solution of electrodialysis enters an evaporation crystallization unit, and the crystallization solid is recovered to realize nitrogen recovery. Meanwhile, by refluxing a part of the effluent of the biological nitrification unit, the fresh water of the electrodialysis and evaporative crystallization unit, the reuse of the regenerated liquid and the zero liquid discharge of a side stream are realized.

(7) The hardness ions are recovered by precipitation, and Mg (OH) can be recovered simultaneously₂And calcium carbonate to avoid the influence of the accumulation of hardness ions on the ion exchanger, while Mg (OH)₂May be used to recover MAP.

(8) The added carbonate and bicarbonate provide alkalinity for biological nitrification, and maintain the proper pH range of the inlet water of the biological nitrification unit. The nitrifying bacteria are autotrophic bacteria, and the nitrification efficiency of the nitrifying bacteria can be improved by maintaining proper alkalinity and pH. Meanwhile, the hardness ion recovery agent and the alkalinity supplement agent can also supplement metal cations for the regeneration liquid I, so that the concentration of the metal cations in the regeneration liquid I is maintained, and efficient regeneration is ensured.

(9) During the recovery of phosphorus, Ca is added²⁺And when the medicament is recovered, metal cations are supplemented for the regeneration liquid II, so that the concentration of the metal cations in the regeneration liquid II is maintained, and efficient regeneration is ensured.

(10) By a combination of phosphorus ion exchange/regeneration and partial ammonia nitrogen ion exchange/regeneration, and using Mg (OH) recovered from the wastewater₂The MAP recovery is realized, and the low-efficiency recovery caused by unbalanced nitrogen-phosphorus molar ratio in the sewage is avoided. Meanwhile, the recovery of MAP also effectively reduces NH in the regenerated liquid₄ ⁺And PO₄ ^3-Concentration of NH in the regeneration liquid₄ ⁺And PO₄ ^3-The regeneration of the ion exchanger is inhibited, the recycling of the regeneration liquid is realized, and the high-efficiency regeneration of the ammonia nitrogen ion exchanger and the phosphorus ion exchanger is maintained.

(11) The ComRec process is creatively integrated by coupling anaerobic biological treatment, ammonia nitrogen ion exchange, aerobic biological treatment and phosphorus ion exchange. The utility model provides a ComRec technology has realized that the high efficiency of carbon, nitrogen, phosphorus pollutant in the sewage is got rid of in coordination and the comprehensive resourceization of sewage, goes out water quality of water and can reach the most strict emission standard of present whole world, has advantages such as HRT is short, area is little, the treatment effeciency is high, the rate of recovery of resources is high, reforms transform, alleviates water eutrophication and comprehensive resourceization to sewage treatment plant's upgrading and has important actual engineering meaning.

Drawings

FIG. 1 is a schematic view of the process flow of the present invention;

FIG. 2 is a graph showing the water quality effects of the pilot test run for 30 days in example 2;

FIG. 3 is a diagram of the mass flow analysis of example 2.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In each of the following embodiments or examples,

if no specific material, equipment structure, or processing technique is used, it is intended that the conventional commercial product, conventional commercial equipment, or conventional processing technique be used.

On the one hand, the utility model provides a synchronous high-efficient pollutant is got rid of and comprehensive resource recovery's sewage treatment plant, its structure is referred to as shown in figure 1, include:

mainstream sewage treatment system: comprises an anaerobic bioreactor 1, an ammonia nitrogen ion exchange unit, an aerobic bioreactor 4 and a phosphorus ion exchange column 5 which are connected in sequence along the sewage treatment direction through a main stream sewage pipeline;

nitrogen recovery side stream system: the method comprises the steps of sequentially connecting a magnesium recovery sedimentation tank 6, a first calcium recovery sedimentation tank 7, a biological nitrification reactor 8 and a first regenerated liquid storage tank 9 on the side part of an ammonia nitrogen ion exchange unit through pipelines, wherein the first regenerated liquid storage tank 9 is also connected with the ammonia nitrogen ion exchange unit in a return way;

phosphorus recovery side stream system: the device comprises a second calcium recovery sedimentation tank 12, a phosphorus ion exchange column 5 and a second regenerated liquid storage tank 13 which are sequentially connected with the side part of the ammonia nitrogen ion exchange unit through pipelines, wherein the second regenerated liquid storage tank 13 is also connected with the ammonia nitrogen ion exchange unit in a returning way.

In a specific embodiment, the ammonia nitrogen ion exchange unit comprises a first ammonia nitrogen ion exchange column 2 and a second ammonia nitrogen ion exchange column 3 which are arranged side by side, wherein the first ammonia nitrogen ion exchange column 2 is connected into the nitrogen recovery side flow system, and the second ammonia nitrogen ion exchange column 3 is connected into the phosphorus recovery side flow system.

In a specific embodiment, the first regeneration liquid storage tank 9 is also connected to and heated by a sewage source heat pump, preferably at a temperature of 15-50 ℃.

In a specific embodiment, the biological nitrification reactor 8 is further provided with a first aeration pump; the aerobic bioreactor 4 is also provided with a second aeration pump.

In a specific embodiment, the first regeneration liquid storage tank 9 is sequentially connected with an electrodialysis module and an evaporation crystallization module along the flowing direction in the nitrogen recovery side flow system, and the electrodialysis module and the evaporation crystallization module are respectively and back connected with the ammonia nitrogen ion exchange unit.

In a specific embodiment, the magnesium recovery sedimentation tank 6 and the first calcium recovery sedimentation tank 7 are respectively provided with a magnesium recovery doser and a first calcium recovery doser, the second calcium recovery sedimentation tank 12 is provided with a second calcium recovery doser, and the second regeneration liquid storage tank 13 is further respectively connected with a pH adjusting tank and a mg (oh)₂A dosing box.

In a specific embodiment, the anaerobic bioreactor 1 may be one or more of a combination of an anaerobic contact digester, a UASB, an internal circulation anaerobic reactor, an anaerobic granular sludge expanded bed, an AnMBR, an anaerobic fluidized bed, and an anaerobic rotating biological disk.

In a specific embodiment, the inoculated sludge in the anaerobic bioreactor 1 may be one or more of excess sludge from a municipal sewage treatment plant, anaerobic sludge, anaerobically digested sludge, and anaerobic granular sludge.

In a specific embodiment, the aerobic bioreactor 4 can be one or a combination of BAF, MBR, aerobic tank + secondary sedimentation tank reactor. More preferably, the SRT of aerobic bioreactor 4 is between 5 and 500 days. More preferably, the HRT of the aerobic bioreactor 4 is 0.5-48 h.

In a specific embodiment, the wastewater to be treated is recycled water or secondary effluent water treated by a wastewater treatment plant.

In one embodiment, the phosphorous ion exchange column 5 operates in an upflow or vertical mode.

On the other hand, the utility model provides a synchronous high-efficient pollutant is got rid of and comprehensive resource recovery's sewage treatment process, its adoption is implemented as above-mentioned sewage treatment plant, specifically refer to as shown in figure 1, this sewage treatment process includes following step:

(1) the sewage to be treated is sent into an anaerobic bioreactor 1 for anaerobic biodegradation treatment, the treated sewage is sent into an ammonia nitrogen ion exchange unit consisting of a first ammonia nitrogen ion exchange column 2 and a second ammonia nitrogen ion exchange column 3 side by side to remove ammonia nitrogen, then the sewage enters an aerobic bioreactor 4 for deep decarburization, and finally the sewage is discharged after being dephosphorized in a phosphorus ion exchange column 5;

(2) the regeneration liquid for regenerating the ammonia nitrogen ion exchange unit is divided into two streams, wherein one stream is the regeneration liquid I fed from a first regeneration liquid storage tank 9, the other stream is the regeneration liquid II fed from a second regeneration liquid storage tank 13, the regeneration liquid I is fed into a nitrogen recovery side flow system after regenerating the first ammonia nitrogen ion exchange column 2, the regeneration liquid I sequentially enters a magnesium recovery sedimentation tank 6 and a first calcium recovery sedimentation tank 7 for hardness ion precipitation recovery, then enters a biological nitration reactor 8 for nitration treatment, and then returns to the first regeneration liquid storage tank 9, one part of the regeneration liquid I in the first regeneration liquid storage tank 9 continuously sequentially flows into an electrodialysis module and an evaporation crystallization module for treatment, a crystallized product is recovered, and the other part of the regeneration liquid I flows back to the first ammonia nitrogen ion exchange column 2;

(3) the regenerated liquid II is sent into a phosphorus recovery side flow system after regenerating the second ammonia nitrogen ion exchange column 3, firstly enters a second calcium recovery sedimentation tank 12 for calcium ion precipitation recovery, then enters a phosphorus ion exchange column 5 for completing phosphorus ion regeneration, finally returns to a second regenerated liquid storage box 13, and is added with Mg (OH) in the second regenerated liquid storage box 13 by adjusting pH₂And generating MAP, and realizing synchronous recovery of nitrogen and phosphorus and regeneration of the regeneration liquid II.

In a specific embodiment, in the step (1), the flow rate ratio of the sewage respectively flowing into the first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ion exchange column 3 is equal to the phosphorus and NH in the sewage₄ ⁺-molar ratio of N.

In a specific embodiment, the ammonia nitrogen ion exchanger used in the first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ion exchange column 3 is selected from one or more of natural zeolite, modified zeolite, molecular sieve, fly ash or ion exchange resin. More preferably, the regeneration mode of the ammonia nitrogen ion exchanger can be concurrent regeneration or countercurrent regeneration.

In a specific embodiment, the phosphorus ion exchanger used in the phosphorus ion exchange column 5 is one or more of anion exchange resin, modified zeolite, modified biochar or molecular sieve.

In a specific embodiment, the regeneration liquid I is a mixed solution of one or more of sodium nitrate, potassium nitrate or calcium nitrate, and the concentration of the mixed solution is 0.01-100 g/L;

in a specific embodiment, the regeneration liquid II is a mixed solution of one or more of sodium chloride, potassium chloride, magnesium chloride, sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate, and the concentration of the mixed solution is 0.01-100 g/L.

In a specific embodiment, the empty column residence time (EBCT) of the sewage in the first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ion exchange column 3 is 1-600 min;

the EBCT of the sewage in the phosphorus ion exchange column 5 is 1-600 min.

In a specific embodiment, the regeneration liquid I and the regeneration liquid II respectively regenerate the first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ion exchange column 3 for 0.1-72 h.

In a specific embodiment, the regeneration liquid II is regenerated for 0.1 to 72 hours on the phosphorus ion exchange column 5.

In a specific embodiment, the pH in second regenerant liquid reservoir tank 13 is controlled to be 6.0-12.0.

In a specific embodiment, the calcium removing agent used in the first calcium recovery and precipitation tank 7 is one or more of carbonate and bicarbonate, and the calcium recovery agent used in the second calcium recovery and precipitation tank 12 is one or more of carbonate, bicarbonate and polyphosphate.

In a specific embodiment, the magnesium recovery agent used in the magnesium recovery and precipitation tank 6 is one or more of sodium hydroxide, lime, calcium hydroxide, carbonate and bicarbonate.

In a specific embodiment, the biological nitrification reactor 8 can be one or a combination of MBR, moving bed biofilm reactor, aerobic tank + sedimentation tank + membrane pretreatment, BAF. More preferably, the pH value of the inlet water is controlled to be 6.0-10.0, the inlet water temperature is controlled to be 15-40 ℃, and the inlet water NH is controlled₄ ⁺The concentration of N is 25-2000mg/L, and the SRT is 1-500 d. More preferably, the DO of the biological nitrification reactor 8 is controlled to be 0.5 to 8 mg/L.

In a particular embodiment, the HRT of the regeneration liquid to be treated in the biological nitrification reactor 8 is 1-48 h.

In a specific embodiment, the ratio of the regeneration liquid I in the first regeneration liquid storage tank 9 flowing into the electrodialysis module can be adjusted to 0-100% as required.

In a specific embodiment, electricityFeed water NO for dialysis module₃The concentration is 200-20000 mg/L.

In a particular embodiment, the HRT of the dilute chamber of the electrodialysis module can be between 0.1 and 24 h; the HRT of the concentration chamber can be 0.1-24 h. Preferably, the electrode compartment electrolyte of the electrodialysis module is one or more of sodium sulfate, potassium sulfate, sodium chloride and potassium chloride.

In a specific embodiment, the ion exchange membrane of the electrodialysis module can be one or more of a homogeneous membrane, a heterogeneous membrane, a bipolar membrane, and an electrophoretic electrolyte membrane. The flow rate ratio of the dilute and concentrate chambers can be from 1:1 to 50: 1.

In a specific embodiment, the evaporative crystallization unit may employ one or more combinations of Mechanical Vapor Recompression (MVR) evaporator, multiple effect evaporator, waste water evaporator, forced circulation evaporator, continuous crystallization evaporator, falling film evaporator, rotating wiped film evaporator.

In a specific embodiment, the reagent for adjusting the pH of the second regeneration liquid storage tank 13 may be one or more of sodium hydroxide, potassium hydroxide, lime, magnesium oxide, sodium carbonate, sodium bicarbonate, magnesium hydroxide, hydrochloric acid, sulfuric acid, and the like.

The above embodiments may be implemented individually, or in any combination of two or more.

The above embodiments will be described in more detail with reference to specific examples.

Example 1

A sewage treatment process for synchronously and efficiently removing pollutants and fully recovering resources is shown in a process flow chart of figure 1, and a main flow process comprises the working procedures of anaerobic biological reaction, ammonia nitrogen ion exchange/regeneration, aerobic biological reaction treatment, phosphorus ion exchange/regeneration and the like. The sidestream nitrogen recovery process comprises the working procedures of first ammonia nitrogen regeneration, hardness ion recovery, biological nitrification, electrodialysis concentration, evaporative crystallization and the like. The side stream phosphorus recovery process comprises secondary ammonia nitrogen regeneration and Ca²⁺Recovery, phosphorus regeneration, MAP precipitation recovery and the like.

In the mainstream process, the anaerobic bioreactor unit comprises a sewage inlet pump 20, a sewage inlet valve 24, an anaerobic bioreactor 1, a gas collecting valve 25 and a gas collecting tank 14 which are connected in sequence. The ammonia nitrogen ion exchange unit comprises a first ammonia nitrogen ion exchange column 2 and a second ammonia nitrogen ion exchange column 3 which are arranged side by side and filled with ammonia nitrogen ion exchangers, and a first ammonia nitrogen ion exchange column water inlet valve 26 and a second ammonia nitrogen ion exchange column water inlet valve 27 which are respectively arranged at the water inlet positions of the first ammonia nitrogen ion exchange column and the second ammonia nitrogen ion exchange column. The aerobic biological reaction treatment is mainly carried out in the aerobic biological reactor 4, and the bottom of the aerobic biological reactor is also provided with a second aeration pump 29. In addition, the apparatus for performing the phosphorus ion exchange includes a phosphorus ion exchange column feed valve 30 and a phosphorus ion exchange column 5 packed with a phosphorus ion exchanger.

In the sidestream nitrogen recovery process, the regeneration liquid I in the first regeneration liquid storage box 9 sequentially passes through the storage box water outlet valve 40, the regeneration liquid I inlet pump 22 and the first nitrogen recovery regeneration liquid inlet valve 45 and enters the first ammonia nitrogen ion exchange column 2. The first regenerated liquid storage tank 9 is also connected to a source of sewage heat pump 46. Then, the regeneration liquid I to be treated coming out of the first ammonia nitrogen ion exchange column 2 sequentially enters a subsequent hardness ion recovery unit and the like for treatment. The hardness ion recovery unit comprises a magnesium recovery sedimentation tank water inlet valve 35, a magnesium recovery sedimentation tank 6, a first calcium recovery sedimentation tank water inlet valve 36 and a first calcium recovery sedimentation tank 7 which are connected in sequence. The magnesium recovery sedimentation tank 6 and the calcium recovery sedimentation tank 7 are also respectively connected with a magnesium recovery doser 15 and a first calcium recovery doser 16.

The biological nitrification unit comprises a biological nitrification reactor water inlet valve 37 and a biological nitrification reactor 8 which are connected in sequence. The biological nitrification reactor 8 is also connected with a first aeration pump 38. The electrodialysis unit comprises an electrodialysis water inlet valve 41, an electrodialysis reactor 10 and an electrodialysis fresh water outlet valve 11 which are connected in sequence. The evaporative crystallization unit comprises an evaporative crystallization water inlet valve 43, an evaporative crystallization device 11 and an evaporative crystallization fresh water outlet valve 44 which are connected in sequence.

In the sidestream phosphorus recovery process, the regeneration liquid II in the second regeneration liquid storage tank 13 sequentially passes through the regeneration liquid II water inlet pump 23 and the regeneration liquid II water inlet valve 34 to enter the second ammonia nitrogen ion exchange column 3, the regeneration liquid II to be treated flows out from the side part of the second ammonia nitrogen ion exchange column 3 through the regeneration liquid II water outlet valve 31 and then enters the second calcium recovery unit, namely the second calcium recovery sedimentation tank 12, and a second calcium recovery sedimentation tank water outlet valve 32 is further arranged between the second calcium recovery sedimentation tank 12 and the phosphorus ion exchange column 5. The second calcium recovery sedimentation tank 12 is also connected with a second calcium recovery doser 17.

A water outlet valve 33 of the regeneration liquid II of the phosphorus ion exchange column is arranged behind the phosphorus ion exchange column 5 and is connected with a second regeneration liquid storage tank 13. The MAP precipitation reaction is carried out in a second regeneration liquid storage tank 13, and the second regeneration liquid storage tank 13 is connected with a pH adjusting tank 18 and a magnesium source doser 19.

The method comprises the following specific steps: the domestic sewage to be treated is pumped into the anaerobic bioreactor 1 by a sewage inlet pump 20 through a sewage inlet valve 24, a gas collecting valve 25 is opened, and the sewage enters the first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ion exchange column 3 after anaerobic treatment. After the ammonia nitrogen ion exchanger rapidly captures ammonia nitrogen in the sewage, the sewage enters the aerobic bioreactor 4 through an aerobic bioreactor water inlet valve 28. After aerobic decarburization and nitrification, the sewage enters the final phosphorus ion exchange column 5, phosphorus in the sewage is rapidly captured by the phosphorus ion exchanger, and then water is discharged.

And after the set ion exchange time is reached, the sewage inlet pump 20 is closed, and the first ammonia nitrogen ion exchange column 2, the second ammonia nitrogen ion exchange column 3 and the phosphorus ion exchange column 5 are emptied for regeneration.

During regeneration, the regeneration liquid I in the first regeneration liquid storage tank 9 is heated by the sewage source heat pump 46 and pumped into the first ammonia nitrogen ion exchange column 2 by the regeneration liquid I inlet pump 22. The regenerated liquid II in the second regenerated liquid storage tank 13 passes through a regenerated liquid II inlet pump 22, sequentially enters the second ammonia nitrogen ion exchange column 3 and the phosphorus ion exchange column 5 through a regenerated liquid II inlet valve 34, and then flows back into the second regenerated liquid storage tank 13 through a phosphorus ion exchange column regenerated liquid II outlet valve 33 to form a cyclic regeneration treatment system. And (3) closing the regeneration liquid I water inlet pump 22 and the regeneration liquid II water inlet pump 23 after the regeneration is finished, allowing the regeneration liquid I and the regeneration liquid II to completely flow back to the first regeneration liquid storage tank 9 and the second regeneration liquid II storage tank 13, completing the regeneration, and standing the first ammonia nitrogen ion exchange column 2, the second ammonia nitrogen ion exchange column 3 and the phosphorus ion exchange column 5 until the next operation.

The regenerated liquid I flows out of the first ammonia nitrogen ion exchange column 2 and enters a magnesium recovery sedimentation tank 6 through a water inlet valve 35 of the magnesium recovery sedimentation tank. Adding a magnesium recovery precipitator into the magnesium recovery sedimentation tank 6 through a magnesium recovery doser 15, stirring, settling after full reaction, and finally discharging the precipitate through a mud bucket. The supernatant flows out of the magnesium recovery sedimentation tank 6 and enters the calcium recovery sedimentation tank 7 through a first calcium recovery sedimentation tank water inlet valve 36. And a calcium recovery dosing device 16 is used for dosing a calcium recovery precipitator into the calcium recovery sedimentation tank 7, stirring, settling after full reaction, and finally discharging the precipitate through a mud bucket. The regenerated liquid enters the biological nitrification reactor 9 through the biological nitrification reactor water inlet valve 37 after recovering the hardness ions, and after nitrification is completed, the regenerated liquid I flows back to the first regenerated liquid storage tank 9 through the regenerated liquid storage tank water inlet valve 39. Part of the regeneration liquid I is fed from the first regeneration liquid storage tank 9 to the electrodialysis reactor 10 via the electrodialysis water inlet valve 41. After the anion and cation separation of the regeneration liquid I is completed in the electrodialysis reactor 10, the fresh water flows back to the first regeneration liquid storage tank 9 through the electrodialysis fresh water backflow valve 42. The concentrated water enters the evaporative crystallization device 11 through the evaporative crystallization water inlet valve 43, and the condensed water vapor flows back to the first regenerated liquid storage tank 9 through the evaporative crystallization fresh water reflux valve 44. Fresh water of the electrodialysis reactor 10 and the evaporative crystallization device 11 is respectively converged into the outlet water of the first regeneration liquid storage tank 9 through an electrodialysis fresh water reflux valve 42 and an evaporative crystallization fresh water reflux valve 44 to be recycled. The crystalline solid from the evaporative crystallization unit 13 is a nitrogen recovery product.

The regenerated liquid II flows out of the second ammonia nitrogen ion exchange column 3 and enters the second calcium recovery sedimentation tank 12 through a regenerated liquid II water outlet valve 31. And a second calcium recovery doser 17 is used for adding a calcium recovery precipitator II into the second calcium recovery sedimentation tank 12, stirring, settling after full reaction, and finally discharging the precipitate through a mud bucket. The regeneration liquid II flows out from the phosphorus ion exchange column 5 and enters the second regeneration liquid storage tank 13 through a water outlet valve 33 of the phosphorus ion exchange column regeneration liquid II. And a pH adjusting box 18 and a magnesium source doser 19 are used for adding a pH adjusting agent into the second regenerated liquid storage box 13, supplementing a magnesium source, stirring, settling after full reaction, and finally discharging precipitates through a mud bucket. The precipitate is the phosphorus recovery product.

Example 2

COD, TN and NH of inlet water of certain sewage treatment plant₄ ⁺The concentration of-N, TP is 300, 27.5, 25.0 and 3.0mg/L respectively, and the treated product needs to reach GB18918-2002 first grade A standard (COD)<50mg/L，NH₄ ⁺-N< 5mg/L，TP<0.5 mg/L). A ComRec process is adopted for pilot plant research, and the pilot plant water treatment amount is 2 tons/day and the duration is 30 days.

For the above-mentioned sewage to be treated, the apparatus of example 1 was used for the treatment. Specifically, the anaerobic bioreactor adopts UASB, HRT is 4h, and the reaction temperature is maintained at 35 ℃. Sewage is pumped into UASB by a water inlet pump 20 through a sewage inlet valve 24, 200L of methane can be recovered every day, effluent of the UASB enters a first ammonia nitrogen ion exchange column 2 and a second ammonia nitrogen ion exchange column 3 respectively, wherein the volume of the first ammonia nitrogen ion exchange column 2 is 15L, and the total volume of the second ammonia nitrogen ion exchange column 3 is 5L. The first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ion exchange column 3 are filled with natural zeolite, EBCT is 1h, the adsorption operation time is 20h, the water treatment capacity per hour is 20L/h, and the water treatment capacity per operation is 400L. 5 groups of first ammonia nitrogen ion exchange columns 2 and second ammonia nitrogen ion exchange columns 3 are adopted to run in parallel, and 2 groups of first ammonia nitrogen ion exchange columns and second ammonia nitrogen ion exchange columns are reserved. The aerobic bioreactor 4 adopts BAF, HRT is 1h, effective volume is 50L, and two groups of aeration biological filters (i.e. BAF) are adopted to operate simultaneously. BAF effluent enters a phosphorus ion exchange column 5, anion exchange resin is filled in the phosphorus ion exchange column 5, the volume is 10L, the EBCT is 0.5h, 5 groups of phosphorus ion exchange columns are adopted to run in parallel, and 2 groups are used for standby. Average effluent COD, TN, NH of ComRec process during operation₄ ⁺The N and TP concentrations were 17.8, 1.8, 0.2 and 0.4mg/L, respectively (FIG. 2).

And after the preset running time (24h) is reached, emptying the first ammonia nitrogen exchange column 2, the second ammonia nitrogen exchange column 3 and the phosphorus ion exchange column 5, and pumping the sewage into the first ammonia nitrogen exchange column 2, the second ammonia nitrogen exchange column 3 and the phosphorus ion exchange column 5 for later use by a sewage intake pump 24 to continuously treat the sewage. The regeneration liquid I adopts a sodium nitrate solution, the concentration of sodium ions is 10g/L, and the volume of the regeneration liquid is 150L. Sodium hydroxide and sodium carbonate-sodium bicarbonate are respectively used as a magnesium recovery precipitator and a calcium recovery precipitator I to be added into a magnesium recovery precipitation tank 6 and a first calcium recovery precipitation tank 7 (the adding amount of the sodium hydroxide and the sodium carbonate-sodium bicarbonate can completely precipitate hardness ions in the regeneration liquid), 92.5g of magnesium hydroxide is recovered every day, and the recovered magnesium hydroxide meets the first-class standard of the general industry type in the industrial magnesium hydroxide (HG/T3607-2007), and the details are shown in Table 1.

TABLE 1 index comparison of recovered magnesium hydroxide and magnesium hydroxide in domestic wastewater

The supernatant of the first calcium recovery sedimentation tank 7 enters the biological nitrification reactor 8 through a biological nitrification reactor water inlet valve 26. The biological nitrification reactor 8 adopts MBR, the volume is 700L, the operation condition is HRT (high resolution) 8h, SRT (fast recovery turbine) 100d, DO (DO) is controlled at 4-5mg/L, and the inlet water temperature is controlled at 32 ℃. MBR effluent NO₃ ^-The concentration of N is 4730mg/L, MBR effluent flows into a first regeneration

liquid storage tank

9, and 5 percent of regeneration liquid I enters the electrodialysis reactor 10 from the first regeneration liquid storage tank 9. In the electrodialysis reactor 10, the total effective membrane area is 40m²The interior of the membrane is provided with 22 cation exchange membranes and 22 anion exchange membranes, and the temperature is controlled at 32 ℃. After the regeneration liquid I to be treated enters the reactor, a fresh water chamber drainage valve 42 and an evaporative crystallization water inlet valve 43 are opened. NO of concentrated water of electrodialysis reactor₃ ^-The concentration of-N is 37840mg/L, NO in fresh water₃ ^-The concentration of N is 46.2mg/L, and the nitrate removal rate is 99.0%. The electrodialysis concentrated water enters an evaporation crystallization device 11, 266g of sodium nitrate is recovered every day, and the recovered sodium nitrate meets the first-class standard of the general industry type in the industrial sodium nitrate GB/T455-2016, and the details are shown in Table 2. After the water vapor is condensed, it is returned through the evaporative crystalline fresh water return valve 44.

The regeneration liquid II adopts sodium chloride solution with the concentration of sodium ions of 10g/LThe volume was 200L. The regenerated liquid II flows out of the second ammonia nitrogen ion exchange column 3 and then enters a second calcium recovery sedimentation tank 12, and the calcium recovery medicament II is sodium carbonate. The supernatant of the second calcium recovery sedimentation tank 6 flows into a phosphorus ion exchange column 5 to regenerate anion exchange resin. After the regeneration is finished, the phosphorus concentration in the regeneration liquid II is 24.3mg/L, NH₄ ⁺-N concentration of 112.7Mg/L, Mg²⁺The concentration was 15.6 mg/L. The regeneration liquid II was poured into a second regeneration liquid reservoir tank 13, the pH was adjusted to 9.5, 82g of the recovered magnesium hydroxide was added, and 384.7g of MAP precipitate per day was recovered.

TABLE 2 index comparison of sodium nitrate recovered from domestic wastewater with sodium nitrate of the same grade

Compared with patent CN110981077A, the embodiment adopts regeneration-biological nitrification-electrodialysis concentration process at the side stream, and solves NH in the regeneration liquid₄ ⁺The main cause of-N removal is NH₄ ⁺Low N concentration causes high nitrogen recovery cost. Meanwhile, the technology also realizes efficient pollutant removal and comprehensive sewage recycling, and accords with the concepts of circular economy and sustainable development.

Example 3

For COD of 500mg/L, NH₄ ⁺The inlet water of a certain sewage treatment plant with 40mg/L of N and 5mg/L of TP reaches the IV water standard (COD) in GB3838-2002 after being treated<30mg/L，NH₄ ⁺-N<1.5 mg/L，TP<0.3 mg/L). Pilot test research is carried out by adopting ComRec process, and the water treatment amount of the pilot test is 1.0m³And d, the duration is 30 days.

This example is similar to example 2, in which an anaerobic bioreactor was used with an AnMBR, 400L volume, HRT 8 h. The first ammonia nitrogen ion exchange column 2 and the second ammonia nitrogen ionThe ammonia nitrogen ion exchanger in the exchange column 3 is cation exchange resin, 5 groups of first and second ammonia nitrogen ion exchange columns are used for parallel operation, EBCT is 45min, and 2 groups of first and second ammonia nitrogen ion exchange columns are used for standby. Aerobic bioreactor 4 adopts MBR, and the volume is 150L, and operating condition is: HRT 3h, SRT 100d, DO 3-4 mg/L. The phosphorus ion exchanger in the phosphorus ion exchange reactor 5 is anion exchange resin, EBCT is 30min, 5 groups of phosphorus ion exchange columns are adopted to run in parallel, and 2 groups are used for standby. During the pilot test, average effluent COD, TN and NH₄ ⁺The concentration of N and TP is respectively 12.8, 1.1, 0.1 and 0.2mg/L, and the standard of IV class water in GB3838-2002 is met.

The regeneration liquid I and the regeneration liquid II respectively adopt sodium nitrate and sodium chloride solutions with the sodium ion content of 7.5g/L, and the volume is 100L. The biological nitrification reactor 8 adopts MBR, effective volume is 50L, and the operating condition is: HRT 12 h, SRT 150d, DO 4-5mg/L, 32 ℃. NO in MBR effluent₃ ^-The concentration of N was 3360.6 mg/L. In the electrodialysis reactor 10, the total effective membrane area is 10m²The interior of the membrane is provided with 16 cation exchange membranes and 15 anion exchange membranes, and the temperature is controlled at 30 ℃. NO in concentrated water of electrodialysis reactor₃ ^--N is 20100.6mg/L, NO in fresh water₃ ^--N27.9 mg/L, NO₃ ^-The removal rate was 99.2%. The electrodialysis concentrated water enters an evaporation crystallization device 11, and sodium nitrate is recovered. During the pilot plant test, 127L of methane, 38.6g of magnesium hydroxide, 152.9g of sodium nitrate and 174.6g of MAP were recovered daily.

Example 4

With a treatment capacity of 50000m³For the sewage treatment plant of/d as an example, under strict emission standards, a technical-economic comparison was made between the conventional anaerobic/anoxic/aerobic (AAO) process and the corec process in example 2 by comprehensively considering factors such as floor area, early investment, treatment cost and resource recovery (table 3). The quality of inlet water of a domestic sewage treatment plant is supposed to be 350mg/L COD and BOD₅＝140mg/L，SS＝180mg/L，NH₄ ⁺35mg/L of N, 45mg/L of TN and 5.0mg/L of TP, and the effluent quality is determined to be less than or equal to 30mg/L of COD and BOD₅≤10mg/L，SS≤10mg/L，NH₄ ⁺N is less than or equal to 1.5mg/L, TN is less than or equal to 5mg/L, and TP is less than or equal to 0.3 mg/L. To meet more stringent emission standards, the AAO process is typically combined with a Coagulation Sedimentation Unit (CSU) and a denitrification filter. The ComRec process mainstream system includes an anaerobic reactor (e.g., UASB) for carbon recovery, a nitrate recovery module to treat 92.5% wastewater, NH to treat 7.5% wastewater₄ ⁺Ion exchange unit, BAF and PIE unit for oxidizing organic matter. The side flow system of the nitrate recovery module comprises two sedimentation tanks for calcium and magnesium recovery, SNR, electrodialysis and MVR units; the side-stream system of the PIE unit firstly regenerates NH of 7.5 percent sewage by adopting sodium chloride solution₄ ⁺And the ion exchange unit then flows into the PIE unit to regenerate the phosphorus ion exchanger, and finally enters a calcium removal sedimentation tank and a MAP sedimentation tank to respectively recover calcium salt and MAP.

Considering the reaction tank and the sedimentation tank, the HRT of the conventional process was 26.6 hours, including AAO (25.5 hours), CSU (0.7 hours), and denitrification filter (0.4 hours). Typical HRTs for mainstream UASB, AIR (EBCT), BAF and PIE reactors in the corec process are 6.0, 0.75, 2 and 0.25h, respectively. The total equivalent HRT for the sidestream nitrate recovery system (water inlet rate 92.5%) was 2.09h, with the HRTs for magnesium precipitation, calcium precipitation, SNR, and electrodialysis being 1.0, 0.5, 12, and 1h, respectively. The recommended HRT for sidestream MAP precipitation is 4h, equivalent to 0.16h for mainstream HRT. Therefore, the total HRT for the ComRec process was 11.25 h.

Treatment capacity 50000m³The occupied area of a typical AAO process sewage treatment plant is 6.78hm². The plant area of the sewage treatment plant occupies five parts including sewage treatment, greening, road and sludge treatment and building, and the proportion of the plant area occupies 39.2 percent, 35.9 percent, 14.2 percent, 3.9 percent and 6.6 percent respectively. Assuming that the occupied area of the first 3 parts is in direct proportion to the HRT of the sewage treatment process, the occupied area of the sludge treatment process is in direct proportion to the sludge yield, and the treatment processes of the building occupied area are the same. With a typical HRT of 11.25h, the first three portions of ComRec have a footprint of 2.58hm². Assuming that the sludge yield of ComRec is 10% of that of the AAO process, the occupied area of ComRec sludge treatment is about 0.03hm². Therefore, the total occupied area of the ComRec process sewage treatment plant is 3.05 hm²The reduction is 55.0 percent compared with AAO.

TABLE 3 comparison of the technical economics of the conventional AAO and ComRec processes under stringent domestic wastewater discharge standards

According to the actual engineering data, the processing capacity is 50000m³The early investment of AAO sewage treatment plant of/d is about 1.78 hundred million yuan. For the ComRec process, UASB, AIR, BAF and PIE (50000 m)³The investment of the/d) unit is 1400, 1200 and 800 ten thousand yuan respectively. In a sidestream nitrate recovery system, the upfront investments for the precipitation reactor, SNR, electrodialysis, and MVR devices are 40, 3400, 170, and 73 ten thousand yuan, respectively, while the upfront investment for the ancillary equipment, including the sewage source heat pump and the two regenerant storage tanks, is about 82 ten thousand yuan. The early investment for the sidestream nitrate recovery system and the phosphorus recovery system were 3820 (water inflow rate 92.5%) and 204 ten thousand yuan, respectively. Accordingly, 50000m³The early investment of the ComRec process sewage treatment plant of/d is 0.86 hundred million yuan.

The energy consumption of a real sewage treatment plant is usually used for transport, mixing and aeration. The conveying energy consumption is in direct proportion to the conveying amount of the sewage and sludge mixed liquor. ComRec has no sludge backflow, and the total conveying amount of the ComRec is only 25% of AAO (internal backflow 200%, external backflow 100%). Therefore, the energy consumption for conveying AAO and ComRec is 0.060 and 0.015 kWh/m respectively³. The combined energy consumption for AAO and ComRec was 0.070 (anaerobic, anoxic and CSU) and 0.047 (UASB), respectively. For the AAO process with aerobic HRT as long as 12.0h, the aeration energy consumption is 0.40kWh/m³. As the HRT of the BAF unit in the ComRec process is as short as 2.0h, the aeration energy consumption is 0.07kWh/m³. The side-stream system energy consumption of the ComRec process is converted into the main stream flow for calculation. The energy consumption of the lateral flow conveying is 0.0050 kWh/m³。Mg(OH)₂、CaCO₃The mixing energy consumption of the precipitation unit is 0.0075 and 0.0085kWh/m³. The aeration energy consumption of the SNR system is 0.185kWh/m³The electrodialytic energy consumption is 0.0054kWh/m³The MVR energy consumption is 0.0210kWh/m³. Therefore, the total energy consumption of AAO and ComRec is 0.530 and 0.358kWh/m respectively³。

Coupling the CSU and the denitrification filter with the AAO process, and adding 18.0mg/L AlCl into the CSU₃The unit price is 2800 yuan/ton and 0.4mg/L PAM (18000 yuan/ton), and the residual phosphorus and SS in the AAO effluent are removed. Adding 50mg/L methanol (the unit price is 3500 yuan/ton) into the denitrification filter tank to remove NO₃ ^-Ensure that the TN of the effluent is lower than 5.0 mg/L. Therefore, the cost of the AAO process treatment agent is 0.24 yuan/m³. In the ComRec process, 37mg/L NaOH (2400 RMB/ton unit price) was added to the side stream magnesium removal settler. 294mg/L Na is added into lateral flow regenerant₂CO₃(unit price 1150 yuan/ton) to maintain alkalinity and remove calcium. 26mg/L NaCl (25 yuan/ton unit price) is added into the phosphorus regenerant, so the cost of the ComRec process treatment agent is 0.42 yuan/m³. The domestic common sludge treatment and disposal routes are sludge concentration, anaerobic digestion, dehydration and landfill, and the treatment cost is 1800 yuan/ton dry solid (tDS). Calculated according to the apparent yield of the AAO process sludge of 0.4gSS/gCOD, the per ton water sludge yield is 0.1kgDS, and the sludge treatment and disposal cost is 0.18 yuan/m³. The ComRec process adopts anaerobic biological treatment, the per ton water sludge yield is 0.02kgDS, and the sludge treatment and disposal cost is 0.036 yuan/m³。

In the traditional process, the AAO, CSU and denitrification filter tank do not recover any resources. After the resources of the utility model are recovered, 157g NaNO is recovered from each ton of water treated by ComRec process₃(unit price is 3900 yuan/ton), 100g CaCO₃(unit price 900 yuan/ton), 20.3g Mg (OH)₂(unit price of 2100 yuan/ton) and 36.8g of magnesium ammonium phosphate (unit price of 8200 yuan/ton). The process can recover 0.03kg of CH per ton of water₄The power generation capacity was 0.154 kWh. Considering that the energy cost is 0.88 yuan/kWh, the total benefit of the ComRec process after resource recovery is 1.18 yuan/m³。

The total cost of the AAO and ComRec processes per ton of water treatment is 0.88 yuan/m and 0.81 yuan/m respectively³. After the resources are recovered, the ComRec process can be profitable, and the profit is 0.38 yuan/m³。

Considering that the annual domestic sewage treatment amount in the world is 355 hundred million tons, the application of the ComRec process can greatly save the occupied area of a sewage treatment plant, and the total area of the world is 2.65 multiplied by 10⁷hm²Corresponding to 16 times of the area of Beijing. The ComRec process not only saves a large amount of land and investment on a global scale, but also avoids subsequent complex sludge treatment and disposal. According to the actual engineering data, the early investment required by the AAO process is 1.78 billion yuan, which is 2.07 times that of the ComRec process. Because the aeration quantity required by nitrification is greatly reduced, the total energy consumption of the ComRec process is 67.6 percent of that of the AAO process. The chemical consumption of ComRec process is 0.42 yuan/m³A large part of which is the alkalinity required for SNR nitration. In the ComRec process, the sludge production is significantly reduced due to the lower anaerobic microorganism yield, and the sludge treatment and disposal cost is 20.2% of AAO. After resources are recovered, the ComRec process can obtain 0.38 yuan per ton of water, which is not only beneficial to environmental protection and resource recovery, but also provides an economically feasible and promising new process for sewage treatment for future sewage treatment plants.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims

1. The utility model provides a sewage treatment plant that synchronous high-efficient pollutant was got rid of and comprehensive resource recovery, its characterized in that includes:

2. The sewage treatment device for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 1, wherein the ammonia nitrogen ion exchange unit comprises a first ammonia nitrogen ion exchange column and a second ammonia nitrogen ion exchange column which are arranged side by side, wherein the first ammonia nitrogen ion exchange column is connected into the nitrogen recovery side flow system, and the second ammonia nitrogen ion exchange column is connected into the phosphorus recovery side flow system.

3. The sewage treatment plant for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 1, wherein along the flow direction in the nitrogen recovery side flow system, the first regeneration liquid storage tank is sequentially connected with the electrodialysis module and the evaporation crystallization module, and the electrodialysis module and the evaporation crystallization module are respectively and back-connected with the ammonia nitrogen ion exchange unit.

4. The sewage treatment device for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 3, wherein the electrodialysis module comprises an electrodialysis water inlet valve, an electrodialysis reactor and an electrodialysis fresh water return valve which are connected in sequence, wherein the electrodialysis fresh water return valve is returned and connected with the ammonia nitrogen ion exchange unit through a pipeline.

5. The sewage treatment device for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 3, wherein the evaporative crystallization module comprises an evaporative crystallization water inlet valve, an evaporative crystallization device and a condensate water return valve which are connected in sequence, wherein the condensate water return valve is returned and connected with the ammonia nitrogen ion exchange unit through a pipeline.

6. The sewage treatment device for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 1, wherein a magnesium recovery doser and a first calcium recovery doser are respectively arranged on the magnesium recovery sedimentation tank and the first calcium recovery sedimentation tank, and a second calcium recovery doser is arranged on the second calcium recovery sedimentation tank.

7. The sewage treatment plant for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 1, wherein the second regenerated liquid storage tank is further connected with a pH adjusting tank and Mg (OH)₂A dosing box.

8. The sewage treatment plant for synchronous efficient pollutant removal and comprehensive resource recovery according to claim 1, wherein the first regeneration liquid storage tank is further connected with a sewage source heat pump.

9. The sewage treatment plant with synchronous and efficient pollutant removal and comprehensive resource recovery of claim 1, wherein the biological nitrification reactor is further provided with a first aeration pump.

10. The sewage treatment plant with synchronous and efficient pollutant removal and comprehensive resource recovery of claim 1, wherein the aerobic bioreactor is further provided with a second aeration pump.