CN110436630B - Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor - Google Patents

Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor Download PDF

Info

Publication number
CN110436630B
CN110436630B CN201910822254.4A CN201910822254A CN110436630B CN 110436630 B CN110436630 B CN 110436630B CN 201910822254 A CN201910822254 A CN 201910822254A CN 110436630 B CN110436630 B CN 110436630B
Authority
CN
China
Prior art keywords
tank
membrane
activated sludge
nitrogen
sewage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910822254.4A
Other languages
Chinese (zh)
Other versions
CN110436630A (en
Inventor
王建新
何小娟
何立
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Water Partner Environmental Engineering Co ltd
Original Assignee
Shanghai Water Partner Environmental Engineering Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Water Partner Environmental Engineering Co ltd filed Critical Shanghai Water Partner Environmental Engineering Co ltd
Priority to CN201910822254.4A priority Critical patent/CN110436630B/en
Publication of CN110436630A publication Critical patent/CN110436630A/en
Application granted granted Critical
Publication of CN110436630B publication Critical patent/CN110436630B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/30—Aerobic and anaerobic processes
    • C02F3/302—Nitrification and denitrification treatment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/16—Nitrogen compounds, e.g. ammonia
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C02F2101/38—Organic compounds containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2203/00—Apparatus and plants for the biological treatment of water, waste water or sewage
    • C02F2203/004—Apparatus and plants for the biological treatment of water, waste water or sewage comprising a selector reactor for promoting floc-forming or other bacteria
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2203/00—Apparatus and plants for the biological treatment of water, waste water or sewage
    • C02F2203/006—Apparatus and plants for the biological treatment of water, waste water or sewage details of construction, e.g. specially adapted seals, modules, connections
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/11—Turbidity
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/14—NH3-N
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/16—Total nitrogen (tkN-N)
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/22—O2
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2301/00—General aspects of water treatment
    • C02F2301/04—Flow arrangements
    • C02F2301/046—Recirculation with an external loop

Abstract

The invention relates to a coupling membrane biological treatment process and a coupling membrane biological treatment reactor for toxic and high-nitrogen-content chemical sewage. The process and the reactor have high removal efficiency and strong shock resistance, and the COD, ammonia nitrogen and total nitrogen of effluent can stably reach the standard; no oxidant and catalyst are used, the operation cost is low, and no secondary pollution is caused; the reactor is of an integrated structure, so that the occupied area is saved, the energy consumption required by the backflow of the mixed liquid and the sludge is reduced, and the engineering investment is low; simple treatment process, convenient operation and maintenance and the like, and can be used in the industrial production of toxic and high-nitrogen-content chemical wastewater.

Description

Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor
Technical Field
The invention belongs to the field of sewage treatment, and particularly relates to a toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor.
Background
Along with the release of industrial standards such as petrochemical industry pollutant emission standard GB31571-2015 and coking chemistry industry pollutant emission standard GB16171-2012, strict ammonia nitrogen and total nitrogen control limit values are provided for chemical wastewater emission. Nitrogen is one of main elements in chemical raw materials or products, and most of chemical sewage contains nitrogen in different forms, so that chemical enterprises are faced with the upgrading transformation of sewage treatment facilities, the removal rate of ammonia nitrogen is improved, and total nitrogen treatment facilities are increased. The secondary biochemical treatment facility with the denitrification function is added behind the existing biochemical treatment facility for upgrading and modification. The first transformation has been basically completed due to BOD in the sewage5Even if a carbon source is added, the problems of slow microbial propagation and low treatment efficiency still exist, and the problem that the total nitrogen exceeds the standard still exists in enterprises. Part of enterprises consider second round of transformation and need new technologies with high treatment efficiency and stable operation; new technologies are also needed for newly built chemical enterprises.
In most chemical wastewater, the wastewater contains contaminants toxic to microorganisms, such as acrylonitrile, cyanide, acetonitrile, phenols, pyridine, etc. These contaminants are themselves biochemically degradable, but when treated biologically, these toxic substances inhibit the growth and reproduction of microorganisms, or even render them non-viable. It can be found in Wuxi kang editions and the 'treatment technology for wastewater difficult to degrade' published by the Chinese light industry Press that the concentrations of toxicity generated by acrylonitrile, phenol, pyridine and the like to aerobic degradation microorganisms are 53mg/L, 64mg/L and 340mg/L respectively. In a nitrification and denitrification treatment system for nitrogen-containing organic sewage, autotrophic nitrifying bacteria are more sensitive to toxic substances, generate inhibition effect at lower concentration, and the nitrification rate can be rapidly reduced along with the increase of the concentration of the toxic substances. Such as: the experiment that the Li Juan Ying 3 months in 2007 "Shanghai university school newspaper" published the inhibition of phenol on the biological nitrification process of wastewater "shows that: as the phenol concentration increased from 0 to 4.72mg/L, the inhibition of phenol to the maximum specific substrate utilization rate increased from 0 to 65%. The doctor of Wang Hanyu, the research on the biological nitrification inhibition by 2-chloro-5-chloromethylpyridine in imidacloprid wastewater, shows that the nitrification inhibition strength is increased along with the increase of the concentration of 2-chloro-5-chloromethylpyridine (CCMP), when the concentration of CCMP is increased from 2.0mg/L to 25.0mg/L, the fastest degradation rate of ammonia nitrogen is reduced from 7.90mg/(gMLSS h) to 0.02mg/(gMLSS h), and the nitrification inhibition rate is increased to 99.38%. In industrial application, the sewage discharge is influenced by production load adjustment and device operation conditions, the water quality fluctuation range is large, and the actually bearable toxic substance concentration of a biological treatment system is far lower than the value obtained by experimental research. Therefore, one of the difficulties in the treatment of toxic and high-nitrogen-content chemical wastewater is how to remove the toxicity of the wastewater. In the prior art, an advanced oxidation method is generally adopted for pretreatment, and after the concentration of toxic pollutants is reduced, biological treatment is carried out. Such as:
chinese patent CN201511005767 discloses an electrocatalytic oxidation reaction device for treating toxic organic wastewater, which is used for treating the toxic organic wastewater, solves the problems of low treatment efficiency and poor treatment effect of the traditional electrode reaction equipment, reduces the power consumption and the treatment cost (20 kWh/m)3Sewage).
Chinese patent CN201510010373 discloses an acrylic fiber wastewater treatment system, which adopts a treatment process comprising: the method comprises the steps of a regulating tank, a wastewater enhanced air flotation tank, an ozone catalytic sedimentation tank, a baffled anoxic anaerobic reaction tank, an aerobic contact oxidation tank, a secondary sedimentation tank and a sand filter tank, wherein the ozone catalytic sedimentation tank is used for reducing the concentration of toxic substances such as acrylonitrile, acetonitrile, cyanide and the like in acrylic fiber wastewater, and then the treatment is carried out by adopting an anaerobic-aerobic biological method.
Chinese patent CN201410743068 discloses a method for treating acrylonitrile and two-step wet acrylic fiber wastewater, which comprises the steps of dividing the wet acrylic fiber production wastewater into acrylonitrile wastewater, polymerization wastewater, spinning wastewater, acid wastewater and other wastewater, pretreating the polymerization wastewater and the acrylonitrile wastewater by a Fenton oxidation process to reduce the concentration of acrylonitrile and cyanide, and then carrying out anaerobic-aerobic or anoxic-aerobic biological treatment.
Chinese patent CN201110031791 discloses a high-concentration pyridine wastewater treatment process and equipment, wherein the treatment process comprises electrocatalytic oxidation, micro-electrolysis, coagulating sedimentation, anaerobic hydrolysis and pressurized contact oxidation, and the electrocatalytic oxidation-micro-electrolysis process is used for reducing the toxicity of pyridine substances in sewage.
The hydroxyl free radical (OH) generated by the advanced oxidation system has strong oxidation capability, can oxidize and decompose a plurality of organic matters which are difficult to be biologically degraded and oxidized by a common chemical oxidation method, and has good removal effect on toxic and difficult-to-degrade organic matters. However, it has the following disadvantages: (1) because the advanced oxidation has no selectivity for removing organic matters, when the advanced oxidation is used as a pretreatment measure, a large amount of easily biodegradable organic matters in the wastewater are simultaneously decomposed, and a large amount of oxidant, catalyst or electric energy is consumed, so the operation cost is very high; (2) the pH value of the sewage is generally controlled in an acidic range in the advanced oxidation reaction, for example, the pH value is 2-4 in the Fenton oxidation reaction, and the pH value is 3-5 in the electrocatalytic oxidation reaction. Before entering a pretreatment facility, the sewage needs to be added with acid to be adjusted to be acidic, and after pretreatment, alkali is added to neutralize the sewage to 7.0-8.1 so as to meet the requirement of subsequent biochemical treatment. The addition of acid-base agents not only generates extra cost, but also has high corrosivity on equipment and pipelines, needs expensive materials and has high investment and maintenance cost; (3) the catalyst added in the advanced oxidation reaction generates a large amount of sludge, belongs to hazardous waste, and increases the environmental burden of enterprises; (4) the advanced oxidation reaction is sensitive to conditions and has higher control requirements.
The method for treating the organic sewage by adopting the biological method has the advantages of low capital cost, low treatment cost, simple operation and the like, but has limitations. The difficulty of adopting a biological method to treat toxic and high-nitrogen chemical wastewater is as follows: how to reduce the toxicity of the sewage and enable the biological treatment system to stably operate; and (II) how to improve the denitrification rate and ensure that the ammonia nitrogen and the total nitrogen in the effluent can reach the standard. In order to solve the problem of increasing the denitrification rate, the principle of biological denitrification needs to be analyzed. The principle of biological denitrification is as follows: firstly, ammoniating organic nitrogen to generate ammonia nitrogen; under aerobic conditions, autotrophic nitrifying bacteria utilize inorganic carbon as a carbon source to carry out nitrification reaction on ammonia nitrogen to generate nitrate nitrogen; and then, under the anoxic condition, the heterotrophic denitrifying bacteria utilize organic matters in the sewage as electron donors and nitrate nitrogen as electron acceptors to reduce the nitrate nitrogen into nitrogen, and finally realize the denitrification of the sewage. In order to realize high-efficiency denitrification, in addition to controlling common factors influencing the nitrification and denitrification processes, such as temperature, nutrient ratio, toxic substance concentration, sludge age and the like, it must be recognized that the conditions required for the nitrification and denitrification reactions are different: (1) the nitration reaction requires sufficient Dissolved Oxygen (DO), and the higher the DO, the higher the nitration rate, generally controlled above 2 mg/L. DO has an inhibitory effect on denitrification, mainly because oxygen competes with nitrate for an electron donor, and molecular oxygen also inhibits the synthesis and activity of nitrate reductase. Therefore, the lower the DO, the higher the denitrification rate; when the dissolved oxygen is 0, if the carbon source is sufficient, the removal rate of the nitrate nitrogen can reach 100 percent theoretically. Because the interior of the sludge floc can still present an anoxic or anaerobic state, DO of the anoxic tank is controlled to be less than 0.5mg/L in industrial application. (2) Inorganic carbon is used as a carbon source in the nitration process, the reaction is carried out under the alkalescent condition, and the proper pH value is 7.5-8.5; a small amount of alkalinity can be released in the denitrification process, and the proper pH value is 7.0-7.5; (3) the ratio of the nitrifying bacteria existing in the aerobic reaction system depends on the ratio of the carbon-containing substances and the Kjeldahl nitrogen in the sewage. The higher the carbon-nitrogen ratio, the higher the activity of heterotrophic oxidizing bacteria, and the rate of oxygen dissolution for mass propagationFast, so that nitrobacteria can not survive and compete; conversely, if the carbon-nitrogen ratio is lower, the proliferation of nitrifying bacteria is promoted. Summer-red is recorded in a Master thesis 'study on the influence of carbon-nitrogen ratio on nitrified sludge extracellular polymers and sludge characteristics', the carbon-nitrogen ratio (C/N) has a remarkable influence on the growth of activated sludge, and under the condition that a carbon source is sufficient, heterotrophic microorganisms multiply to compete with nitrifying bacteria, so that damages such as sludge floating and sludge bulking can be caused. When the carbon source is insufficient, autotrophic nitrifying bacteria are cultured, and the activated sludge grows slowly. In a system with sufficient carbon source, the nitrification performance and sludge-water separation effect of the nitrified sludge are obviously influenced by high C/N, and even if the C/N of inlet water is reduced, the inlet water is difficult to recover. When the C/N reaches 10, the sludge is subjected to viscous expansion caused by non-filamentous bacteria, and the removal effect of the reactor on ammonia nitrogen is poor. According to the data, if the BOD is in the system5If the concentration is more than 20mg/l, the nitrobacteria can be inhibited. Therefore, when the COD of the influent water is high, the organic matter needs to be removed first to keep the COD at a low level, aeration is continued, and sufficient growth time and dissolved oxygen are given to the nitrifying bacteria. (4) The denitrification process requires a sufficient carbon source to complete, but not all COD can be used as a carbon source for denitrification. The "influence of carbon source on biological denitrification" was published in "Industrial Water supply and drainage" in 1996 month 7: the type of the carbon source has great influence on the denitrification effect, and the denitrification rate is fastest when soluble organic matters which are easy to biodegrade, such as methanol, ethanol, glucose and the like, are taken as the carbon source; when various organic matters in the mixed sewage are used as a carbon source, the carbon source is sufficient in the initial stage, the denitrification rate is high, and the carbon source is gradually reduced in the later stage; the carbon source property is also an important factor influencing the denitrification effect, COD/NH3N cannot be used as the sole basis for determining whether the carbon-nitrogen ratio is sufficient. Thus, in order to achieve a higher denitrification rate, the nitrification and denitrification processes should be accomplished in two different reactors.
The early biological denitrification processes mainly comprise A/O, multistage A/O, SBR, oxidation ditches and the like, and in recent years, processes such as short-cut nitrification and denitrification, synchronous nitrification and denitrification and the like are developed and play an important role in sewage treatment. However, when the technologies are used for treating toxic and nitrogenous organic sewage, the propagation of microorganisms is inhibited by toxic substances with higher concentration, and the treatment efficiency is low; the nitrification and denitrification reaction is not carried out under the optimal condition, the denitrification is not thorough, and the total nitrogen of the effluent can not reach the standard; poor anti-pollutant impact capacity, unstable system operation and the like.
Chinese patent CN201310436432 discloses a high-toxicity coking phenol-cyanogen wastewater treatment and recycling system and a wastewater treatment and recycling method. The adopted treatment process comprises air floatation separation, an AHCR anaerobic hydrolysis reactor, a DNCR denitrification reactor, a first-stage OHCR aerobic reactor, a second-stage OHCR aerobic reactor, a secondary sedimentation tank, a high-efficiency sedimentation tank and an advanced oxidation reactor, wherein suspension of the second-stage OHCR aerobic reactor flows back to the DNCR denitrification reactor, coking phenol-cyanogen high-toxicity wastewater containing about 400mg/L of sulfur and about 700mg/L of total nitrogen can be treated and recycled, effluent suspended matters are 59mg/L, COD65mg/L and effluent suspended matters are 2.7mg/L, and the total nitrogen concentration of effluent is not provided. The invention has the following problems: (1) in the air floatation reaction separator, part of volatile phenol and hydrocyanic acid are blown off to the atmosphere by mechanical stirring and air aeration, so that the aim of reducing the toxicity of the sewage is fulfilled. The stripping belongs to pollutant transfer, phenol and cyanogen are difficult to remove when entering a gas phase, and the exhaust gas is overproof. (2) The air stripping has a good removal rate on high-concentration wastewater, is generally used for material recovery in a production process, and cannot reduce the concentration of phenol and cyanogen below a microbial toxicity value by air flotation. (3) The invention only uses the primary pre-denitrification as a facility for removing nitrate nitrogen in the whole process. The pre-denitrification has the advantages of utilizing the carbon source in the inlet water, reducing the additional carbon source and lowering the operation cost. The defect is that the total nitrogen of the effluent from the aerobic biochemical tank can not reach the standard. Since the nitrate nitrogen concentration in the effluent is the same as the suspension returned to the DNCR denitrification reactor. In order to increase the denitrification rate and reduce the nitrate nitrogen content in the effluent, the reflux ratio of the mixed liquor needs to be increased. And the increase of the reflux ratio of the mixed liquor causes the increase of energy consumption on one hand and the increase of DO in the anoxic tank on the other hand, thereby influencing the denitrification rate. Therefore, the highest total denitrification rate of the primary anoxic/aerobic method is about 75%.
Chinese patent CN201310003283 discloses a biochemical treatment method of pyridine-containing sewage, which adopts a water inlet mixing zone, a synchronous nitrification and denitrification tank, an anoxic tank and a membrane biological reaction tank to treat the pyridine-containing sewage. In the invention, high-concentration pyridine-containing sewage is mixed with sludge-water mixed liquor returned from the tail end of the synchronous nitrification-denitrification tank in the water inlet mixing zone, so that the pyridine concentration of the water outlet of the mixing zone is less than or equal to 200 mg/L. The reflux liquid after biochemical treatment is used for diluting the inlet water, so that the effect of reducing the toxicity of the pyridine is achieved, and compared with pretreatment by an advanced oxidation method or dilution by industrial water, the treatment cost is greatly reduced. However, the method adopts the synchronous nitrification and denitrification tank as the measure for ammoniating and nitrifying the refractory nitrogenous organic matters in the pyridine, and the DO is controlled to be 0.3-0.5 mg/L. Has the advantages of reduced energy consumption and external carbon source, and has the disadvantages that DO does not satisfy the optimal condition of nitration reaction, the nitration rate is low, and the total denitrification rate is also low. In addition, pyridine is a non-degradable organic substance, and low DO is not beneficial to the degradation.
Disclosure of Invention
The invention aims to solve the problems that: 1) in the prior treatment technology, advanced oxidation is adopted as pretreatment, a large amount of chemical agents and catalysts are required to be added, the operation cost is high, and a large amount of sludge is generated; 2) in the existing biological treatment technology, the propagation of microorganisms is inhibited by toxic substances with higher concentration, and the treatment efficiency is low; the nitrification and denitrification reaction is not carried out under the optimal condition, the denitrification is not thorough, and the total nitrogen of the effluent can not reach the standard; poor anti-pollutant impact capacity, unstable system operation and the like. The invention provides a coupled biological treatment process and a reactor for toxic and high-nitrogen chemical wastewater, and has the advantages of high removal efficiency, and standard COD, ammonia nitrogen and total nitrogen of effluent; the integrated structure saves the occupied area, and the energy consumption required by the backflow of the mixed liquid and the sludge is low; no oxidant and catalyst are used, and the operation cost is low.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment process and a reactor comprise the following components in series connection in sequence:
the biological selection pool is used for adaptively screening microorganisms in the sewage and carrying out primary treatment on the sewage;
the suspended filler oxidation pond is used for enabling beneficial microorganisms to be implanted and propagated, and degrading characteristic pollutants in the sewage treated by the biological selection pond;
an aerobic activated sludge tank, which degrades organic matters and nitrifies ammonia nitrogen in the sewage treated by the suspended filler oxidation tank;
the anoxic activated sludge tank enables denitrifying bacteria to quickly convert nitrate nitrogen into N2 to escape;
the membrane tank is used for separating sludge and water, discharging the sludge and the water respectively and playing a role in degrading the denitrification residual carbon source;
the biological selection tank is communicated with the suspended filler oxidation tank, the aerobic activated sludge tank and the anoxic activated sludge tank, the biological selection tank is coupled with the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the Membrane tank to form an integrated Membrane bioreactor (Combination of Carrier and Membrane Bio-Reactor, abbreviated as CCMBR), and after the toxic and high-nitrogen chemical wastewater is treated by the coupled Membrane bioreactor (CCMBR), effluent meeting the discharge standard is obtained.
As a preferred scheme, the toxic and high-nitrogen chemical wastewater firstly enters the biological selection tank, and is fully mixed with a suspension liquid which flows back from the tail end of the aerobic activated sludge tank or the anoxic activated sludge tank and a medicament which is added according to needs; wherein the reflux ratio of the sewage to the suspension is 2-10, so that the toxicity concentration, the pH value and the nutrient content of the mixed sewage meet the requirements of biological treatment.
As a preferred scheme, the effluent of the biological selection tank enters a suspended filler oxidation tank, a suspended filler with a large specific surface area is filled in the tank, and the surface of the suspended filler is favorable for the implantation and propagation of dominant microorganisms for degrading characteristic pollutants; the bottom of the pool is provided with a mesopore aerator, the Dissolved Oxygen (DO) is controlled to be more than 4mg/L, so that the filler is in a fluidized state, sufficient oxygen is provided for the propagation of microorganisms, easily degradable organic matters are degraded in a short time, organic nitrogen is aminated, and the situation that oxygen is contended for by the subsequent aerobic pool and nitration reaction is avoided. And a filler intercepting grid is arranged at the outlet of the suspended filler oxidation pond, and the size of the gap of the grid is smaller than the minimum size of the filler.
As a preferred scheme, the effluent of the suspended filler oxidation tank enters an aerobic activated sludge tank and is mixed with activated sludge refluxed from a membrane tank, the reflux ratio can be 50-100%, and the sludge concentration of the aerobic activated sludge tank is controlled to be 5-8 g/L; the return sludge is rich in nitrifying bacteria with long period and dominant bacteria capable of degrading characteristic pollutants, and can accelerate the degradation of refractory organic matters and the nitrification of ammonia nitrogen; and a microporous aerator is arranged at the bottom of the tank, and DO is controlled to be 2-3 mg/L, so that the ammonia nitrogen is fully nitrified.
As a preferred scheme, the nitrate state liquid at the tail end of the aerobic activated sludge tank enters an anoxic activated sludge tank, and a carbon source is added according to 4 times of the total nitrogen concentration in the nitrate state liquid, wherein the carbon source adopts methanol or sodium acetate or glucose and the like which are easy to biodegrade; controlling DO to be less than 0.5 mg/L; a submersible mixer is arranged in the pool to accelerate the mixing of the nitrate liquid and the carbon source and prevent sludge from settling, so that denitrifying bacteria can quickly convert nitrate nitrogen into N2And (4) escaping.
As a preferred scheme, the effluent of the anoxic activated sludge tank enters a membrane tank, an immersed ultrafiltration membrane component is arranged in the membrane tank, aerators are arranged at the bottom of the membrane tank and the bottom of the membrane component, and aerated air not only washes the surface of the membrane and prevents the membrane from being blocked, but also plays a role in degrading denitrification residual carbon sources; the treated effluent is pumped out from the water outlet of the membrane module by a water outlet pump, and the effluent meets the requirements of discharge standards. Activated sludge is completely intercepted in the membrane tank and is refluxed to the aerobic activated sludge tank and/or the suspended filler oxidation tank by a sludge reflux pump, and part of residual sludge is discharged out of the system.
Preferably, the integrated membrane bioreactor (CCMBR) can be a co-constructed reinforced concrete water tank or a steel water tank.
Preferably, the biological selection tank can be used as a pre-aeration tank or a hydrolysis acidification tank; when the aerobic activated sludge is used as a pre-aeration tank, suspension liquid is refluxed from the tail end of the aerobic activated sludge tank, and a reflux device can adopt an air lifter, a submersible water impeller or a sewage pump; when the anaerobic activated sludge is used as a hydrolysis acidification tank, suspension liquid is refluxed from the tail end of the anaerobic activated sludge tank, and a reflux device can adopt a submersible water impeller or a sewage pump.
Preferably, the ultrafiltration membrane component can adopt a hollow membrane or a flat membrane.
The discharge standard of the effluent water treated by the method of the invention refers to the discharge limit value of a general area in petrochemical industry pollutant discharge standard GB31571-2015 or coking chemistry industry pollutant discharge standard GB 16171-2012. If the user has higher requirements, the ammonia nitrogen and the total nitrogen can meet the condition that the ammonia nitrogen is less than 5mg/L and the total nitrogen is less than 15mg/L after the parameters of the aerobic activated sludge tank and the anoxic activated sludge tank are controlled; in addition, by adding an ozone catalytic oxidation facility behind the reactor, part of the COD which is not biochemically degradable is removed, so that the COD of the effluent is less than 50mg/L, and the turbidity of the effluent of the ultrafiltration membrane is less than 5NTU, so that the extra ozone consumption is not increased.
In the method, the toxic and high-nitrogen chemical wastewater firstly enters a biological selection tank, is mixed with a suspension liquid which flows back from the tail end of an aerobic activated sludge tank or an anoxic activated sludge tank and a medicament which is added according to needs, and is subjected to adaptive screening on microorganisms; after the toxic sewage is treated by the biological selection tank, the suspended filler oxidation tank and the aerobic activated sludge tank in the method, toxic pollutants are basically removed, so that the concentration of toxic substances in the inflow water can be diluted by the backflow of the suspension liquid, and the inhibiting effect on heterotrophic microorganisms and autotrophic nitrifying bacteria in a subsequent biological treatment system is reduced; the reflux amount of the suspension depends on the concentration of toxic pollutants in the sewage, and the reflux ratio is 2-10, so that the dilution requirement of the chemical sewage can be basically met; the adding of the medicament is mainly used for adjusting the pH value and supplementing nutrient components such as P, Fe, Ca and the like required by the propagation of microorganisms, and is determined according to the nature of sewage. The effluent of the biological selection tank enters a suspended filler oxidation tank, suspended fillers with large specific surface area are filled in the tank, the filling ratio of the suspended fillers can be 20-60%, and the specific surface area is 200-1200 m2/m3The true specific gravity is 0.95-1.0 g/cm3The surface of the filler is beneficial to the implantation and propagation of dominant microorganisms capable of degrading characteristic pollutants; a mesopore aerator is arranged at the bottom of the tank, and DO (dissolved oxygen) is controlled to be more than 4mg/L, so that the filler is in a fluidized state, and a biological film can grow uniformly; the hollow aerator is adopted to wash the filler, facilitate demoulding and prevent the filler from being blocked; is sufficientThe oxygen degrades easily biodegradable organic matters in the sewage in a short time, so that the ammoniation of organic nitrogen is completed, and the oxygen is prevented from being contended for by the subsequent aerobic tank and the nitration reaction; and a filler intercepting grid is arranged at the outlet of the suspended filler oxidation pond, and the gap of the grid is smaller than the size of the filler. The effluent of the suspended filler oxidation tank enters an aerobic activated sludge tank, and is mixed with sludge returned from the membrane tank, wherein the return ratio is 50-100%, and the sludge concentration of the aerobic activated sludge tank is controlled to be 5-8 g/L; the return sludge is rich in nitrifying bacteria with long generation cycle and dominant strains for degrading difficultly-degradable pollutants, so that the removal rate and removal rate of difficultly-degradable organic matters and ammonia nitrogen can be improved; a microporous aerator is arranged at the bottom of the tank, and DO is controlled to be 2-3 mg/L, so that ammonia nitrogen is fully nitrified; the micro-bubbles can prolong the retention time in the oxidation pond and improve the utilization rate of oxygen. The nitrate state liquid at the tail end of the aerobic activated sludge tank enters an anoxic activated sludge tank, and a carbon source is added according to 4 times of the total nitrogen concentration in the nitrate state liquid; in order to ensure that the denitrification process is carried out more completely and simultaneously control the COD concentration in the effluent of the anoxic activated sludge tank, a carbon source adopts methanol or sodium acetate which is easy to biodegrade; controlling DO in the anoxic tank to be less than 0.5 mg/L; in order to quickly and uniformly mix nitrate liquid and a carbon source and prevent sludge from precipitating, a submersible stirrer is arranged in the tank; under the conditions of sufficient and high-quality carbon source, proper DO and pH and the like, nitrate nitrogen can be completely denitrified and converted into N2And (4) escaping. The effluent of the anoxic activated sludge tank enters a membrane tank, an immersed ultrafiltration membrane component is arranged in the membrane tank, the aperture of the membrane is 0.08-0.5 mu m, and activated sludge flocs and microorganisms can be effectively intercepted, so that nitrobacteria with long generation cycle and dominant strains for degrading difficultly-degradable pollutants can be retained in a biological treatment system; aerators are arranged at the bottom of the membrane tank and the bottom of the membrane component, aerated air not only scours the surface of the membrane and prevents the membrane from being blocked, but also provides enough DO for microorganisms in the membrane tank so as to rapidly degrade the denitrification residual carbon source, and the residual carbon source is easily and completely degraded because the additional carbon source is methanol or sodium acetate; the treated effluent is pumped out from the water outlet of the membrane module by an effluent pump, and the effluent reaches the discharge standard of pollutants in petrochemical industry GB31571-2015 or the discharge standard of pollutants in coking chemical industry GB16171-2012 emission limit requirements for general areas; if the user has higher requirements, the ammonia nitrogen and the total nitrogen can meet the requirement that the ammonia nitrogen is less than 5mg/L and the total nitrogen is less than 15mg/L after the parameters of the aerobic activated sludge tank and the anoxic activated sludge tank are controlled.
In addition, by adding an ozone catalytic oxidation facility behind the reactor, part of non-biodegradable COD (namely hard COD) can be removed, the COD of the effluent can reach less than 50mg/L, and the turbidity of the effluent of the ultrafiltration membrane is less than 5NTU, so that the extra ozone consumption can not be increased; the intercepted activated sludge is returned to the front end of the aerobic activated sludge pool by a sludge return pump, and part of the residual sludge is discharged out of the system. The integrated membrane bioreactor (CCMBR) formed by coupling a biological selection tank, a suspended filler oxidation tank, an aerobic activated sludge tank, an anoxic activated sludge tank and a membrane tank can be determined to adopt a reinforced concrete water tank or a steel water tank according to factors such as actual size, field, investment, construction period and the like. According to the biochemical degradation characteristics of pollutants in the sewage, the biological selection tank can be used as a pre-aeration tank or a hydrolysis acidification tank; when the aerobic activated sludge is used as a pre-aeration tank, the suspension liquid is refluxed from the tail end of the aerobic activated sludge tank, DO in the suspension liquid can be recovered, and the reflux device can adopt an air lifter, a submersible water impeller or a sewage pump; when the anaerobic sludge is used as a hydrolysis acidification tank, suspension liquid is refluxed from the tail end of an anoxic activated sludge tank, so that a hydrolysis environment is easily formed, and the reflux device can not adopt an air lifter and can adopt a submersible water impeller or a sewage pump; the form of the suspension reflux device is determined by comparing the energy consumption and equipment investment required by the lifting according to the treatment scale and the reflux ratio. The ultrafiltration membrane component can adopt a hollow membrane or a flat membrane, and can play the same effect.
In the method, the suspension at the tail end of the aerobic activated sludge tank or the anoxic activated sludge tank is adopted to dilute the inlet water, so that the aim of reducing the toxicity of the sewage is fulfilled. To achieve this, only the energy required for the lift needs to be consumed, and thanks to the integrated reactor of the invention, the height and distance of the lift are minimal, as well as the energy consumption. The traditional method adopts either advanced oxidation pretreatment or dilution by industrial water or low-concentration sewage. The advanced oxidation pretreatment has the defects of high operation cost, high corrosion to equipment and pipelines, secondary pollution and the like; the dilution by using industrial water or low-concentration sewage does not conform to the national policy of energy conservation and emission reduction, the load of treatment facilities is increased, and the energy consumption of operation is increased. Compared with the traditional method, the method for reducing the toxicity of the sewage has the advantages of simple process, low equipment investment, low running cost, convenient operation and the like.
In the method, a suspended filler oxidation tank and an aerobic activated sludge tank are connected in series to serve as an aerobic biological reaction tank. The suspended filler oxidation pond combines the advantages of an activated sludge process and a biofilm process, has the characteristics of rich microbial population, enriched dominant strains, strong impact resistance and the like in the biofilm process, has the advantages of uniform microbial distribution, high pond capacity utilization rate, flexible treatment load adjustment and the like in the activated sludge process, can quickly recover the activity under the impact of overload or toxic pollutants, and ensures that the treatment effect is stable. In the method, the suspended filler oxidation tank is used as a high-load section, DO is controlled to be more than 4mg/L, most organic matters are removed, organic nitrogen is ammoniated, and oxygen contention between the aerobic activated sludge tank and a nitration reaction is avoided; most of toxic organic matters are also degraded, and the inhibition effect on nitrobacteria is reduced; the aerobic activated sludge tank is used as a low-load section, DO is controlled to be 2-3 mg/L, sludge flowing back from the membrane tank is rich in nitrobacteria with long generation cycle and dominant strains for degrading pollutants difficult to degrade, degradation of organic matters difficult to degrade and nitrification of ammonia nitrogen can be accelerated, and the reaction is more thorough. Compared with the traditional aerobic biological reaction tank or short-cut nitrification and denitrification tank, the method has the advantages of high reaction rate, high removal efficiency, strong impact resistance and the like.
In the method, the nitrate nitrogen is removed by adopting the anoxic activated sludge tank arranged at the rear, and the nitrate liquid is subjected to denitrification treatment before being discharged out of the reactor. According to data record and pilot test, under the conditions of sufficient and high-quality carbon source, proper DO, pH and the like, the denitrification rate can reach 100% theoretically, and the total nitrogen removal rate of the reactor can reach more than 90%; the denitrification rate can reach 1.0kgNO3the-N/kgMLSS.d is several times or even tens of times of the preposed denitrification, thereby greatly reducing the retention time of the anoxic tank and saving the occupied area. Conventional pre-denitrificationThe process is that nitrate liquid at the tail end of the aerobic biochemical tank and without denitrification is directly discharged to a secondary sedimentation tank, mud and water are separated and discharged, and the concentration of nitrate nitrogen in effluent is very high. In order to improve the denitrification rate and reduce the nitrate nitrogen content in effluent, the reflux ratio of nitrate liquid needs to be improved; and the reflux ratio of the nitrate liquid is increased, so that on one hand, the energy consumption is increased, and on the other hand, the DO of the anoxic tank is increased, and the denitrification rate is influenced. Therefore, the total denitrification rate by adopting the first-level anoxic/aerobic treatment is about 75 percent at most. In order to reach the standard of the total nitrogen of the effluent, a plurality of stages of anoxic/aerobic processes are required to be connected in series, the flow is long, and the engineering investment and the site space are increased. Compared with the traditional pre-denitrification or short-cut nitrification and denitrification process, the anoxic activated sludge tank in the method has the advantages of high denitrification efficiency, simple flow, less occupied area and the like. Although the carbon source required for denitrification is totally dependent on the added carbon source, the cost is lower compared with the advanced oxidation method or the secondary anoxic/aerobic method.
The end of the reactor adopts an ultrafiltration membrane pool component, so that high-quality effluent can be obtained, the sludge concentration in the reactor can be improved, the sludge age (SRT) of the sludge is prolonged, the sludge load is lower, the propagation and enrichment of dominant strains are facilitated, and the reaction rate is improved.
The toxic and high-nitrogen chemical wastewater is treated by adopting the coupling membrane biological treatment process and the reactor, so that the removal efficiency is high, the impact resistance is strong, and COD (chemical oxygen demand), ammonia nitrogen and total nitrogen in effluent can stably reach the standard; no oxidant and catalyst are used, the operation cost is low, and no secondary pollution is caused; the reactor is of an integrated structure, so that the occupied area is saved, the energy consumption required by the backflow of the mixed liquid and the sludge is reduced, and the engineering investment is low; the method has the advantages of simple treatment process, convenient operation and maintenance and the like, has good practical value and obtains better technical effect.
Drawings
FIG. 1 is a schematic diagram of the architecture and process flow of the system of the present invention;
in the figure, A, toxic and high-nitrogen chemical wastewater: B. nutrient salt; C. a carbon source; D. treated water; E. excess sludge; 1. a sludge reflux pump; 2. a grid; 3. a suspension reflux device; 4. a submersible mixer; 5. an ultra-membrane module; 6. and (6) discharging the water pump.
Detailed Description
The structure of the biological coupling membrane bioreactor (CCMBR) in the invention is shown in figure 1: comprises the following steps of sequentially connecting in series:
the biological selection tank 7 is used for adaptively screening microorganisms in the treatment process of the toxic and high-nitrogen-content chemical wastewater A and carrying out primary treatment on the toxic and high-nitrogen-content chemical wastewater A;
the suspended filler oxidation tank 8 is used for enabling beneficial microorganisms to be implanted and propagated, and degrading characteristic pollutants in the sewage treated by the biological selection tank 7;
an aerobic activated sludge tank 9 for degrading organic matters and nitrifying ammonia nitrogen in the sewage treated by the suspended filler oxidation tank 8;
an anoxic activated sludge tank 10 for the denitrifying bacteria to rapidly convert nitrate nitrogen into N2Escaping;
in the invention, a suspension reflux device 3 is arranged in both the aerobic activated sludge tank 9 and the anoxic activated sludge tank 10.
The membrane tank 11 is used for separating sludge and water, discharging the sludge and the water respectively and playing a role in degrading the denitrification residual carbon source;
the biological selection tank 7 is communicated with the suspended filler oxidation tank 8, the aerobic activated sludge tank 9 and the anoxic activated sludge tank 10, and the biological selection tank 7 is coupled with the suspended filler oxidation tank 8, the aerobic activated sludge tank 9, the anoxic activated sludge tank 10 and the membrane tank 11 to form an integrated membrane bioreactor.
The sewage treated by the biological selection tank 7 enters a suspended filler oxidation tank 8: the suspended filler oxidation pond 8 is filled with suspended fillers with large specific surface area, a mesopore aerator is arranged at the bottom of the suspended filler oxidation pond 8, the dissolved oxygen amount is controlled to be more than 4mg/L, and a filler interception grid 2 is arranged at the outlet of the suspended filler oxidation pond 8. The sewage flowing out of the suspended filler oxidation tank 8 and the activated sludge flowing back from the membrane tank 11 are mixed according to the ratio (0.5-1): 1 is mixed in an aerobic activated sludge tank 9 provided with a microporous aerator, wherein the sludge concentration of the aerobic activated sludge tank 9 is 5-8 g/L, and the dissolved oxygen amount is 2-3 mg/L.
Nitrate state liquid discharged from the aerobic activated sludge tank 9 enters an anoxic activated sludge tank 10 provided with a submersible mixer 4, methanol or sodium acetate or glucose is added as a carbon source C according to the concentration 4 times of the total nitrogen concentration in the nitrate state liquid, and the dissolved oxygen is controlled to be less than 0.5 mg/L.
The effluent of the anoxic activated sludge tank 10 enters a membrane tank 11, an immersed ultrafiltration membrane component 5 is arranged in the membrane tank 11, and the ultrafiltration membrane component 5 is a hollow membrane or a flat membrane. The bottom of the membrane pool and the bottom of the membrane component are both provided with aerators; and pumping the treated water D out of a water outlet of the membrane component by using a water outlet pump 6, refluxing the activated sludge in the membrane tank 11 to the aerobic activated sludge tank 9 and/or the suspended filler oxidation tank 8 by using a sludge reflux pump 1, and discharging part of the residual sludge E out of the toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor.
In the invention, according to the actual situation, the nutrient salt B can be added into the biological selection pool 7 to meet the trace elements required by the propagation of the microorganisms.
Example 1
The sewage produced by certain wet acrylic fiber has the treatment capacity of 150m3H, water quality after removing suspended matters through neutralization and coagulation air flotation: COD: 1000mg/L, total nitrogen: 115mg/L, ammonia nitrogen: 15mg/L, acrylonitrile: 80mg/L, sodium thiocyanate: 100 mg/L.
The treatment process and the reactor structure are shown in figure 1, and the adopted coupled membrane bioreactor (CCMBR) is a reinforced concrete structure.
And after the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank are respectively inoculated with sludge and domesticated for 2-4 weeks, acrylic fiber sewage sequentially enters the biological selection tank, the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank, and finally discharged water is pumped out of an ultrafiltration membrane component of the membrane tank.
The biological selection tank is used as a mixing pre-aeration tank, acrylic fiber production sewage is mixed with suspension liquid returned from the tail end of an aerobic activated sludge tank, an air lifter is adopted to realize return flow, the return flow ratio is 5, and compressed air is utilized to stir and mix; and adding phosphorus salt according to the ratio of C to P of 200:1, and adding alkali liquor to prepare the aerobic activated sludge pool with the pH value of 7.5-8.1.
The effluent of the biological selection tank enters a suspended filler oxidation tank, and the suspended filler in the tank is filledThe filling rate is 35 percent, and the organic load (SALR) on the surface of the filler is 15g/m2d, specific surface area of suspended filler 500m2/m3Controlling DO at 4-5 mg/L; mixed liquor at the tail end of the suspended filler oxidation tank enters the aerobic activated sludge tank through the overflowing hole of the partition wall, and grid meshes are arranged on the overflowing hole to intercept fillers.
The mixed liquor enters an aerobic activated sludge tank and then is mixed with sludge flowing back from a membrane tank, the reflux ratio is controlled to be 75 percent, the sludge concentration is about 5gMLSS/L, the DO at the tail end is about 2mg/L, the removal load of organic matters is designed to be 0.18kgCOD/kgMLSS.d, and the nitrification load is 0.04kgNH3-N/kgMLSS.d。
Nitrate liquid at the tail end of the aerobic activated sludge tank enters an anoxic activated sludge tank, and denitrification load is 0.50kgTN/m3D, adding methanol with concentration of about 300mg/L according to 4 times of total nitrogen concentration of inlet water, controlling DO below 0.5mg/L, and installing a submersible stirrer in the pool.
The effluent of the anoxic activated sludge tank flows into a membrane tank by gravity, and an immersed hollow ultrafiltration membrane component is arranged in the membrane tank. The Hydraulic Retention Time (HRT) of the membrane pool is 2.5h, and the flux of the ultrafiltration membrane is 17L/m2H, total area of MBR ultrafiltration membrane is required to be 8823m2MBR module membrane area 1500m according to standard2Each group, 6 MBR components are needed, the MBR components are divided into 3 rows, each row has 2 MBR components, and each row is matched with one MBR component with the water yield of 75m3A/h variable frequency suction pump. The water quality of the outlet water of the ultrafiltration membrane is as follows: COD is less than or equal to 80mg/L, TN is less than or equal to 25mg/L, NH3N is less than or equal to 5mg/L, and other indexes meet the discharge requirement of pollutant discharge Standard of petrochemical industry GB 31571-2015. 2 sets of 150m3A/h sludge reflux pump and variable frequency control. And part of the residual sludge is discharged from the sludge pump outlet main pipe.
The effluent COD is basically non-biodegradable COD, and if the COD is required to be less than or equal to 60mg/L, an ozone catalytic oxidation tank can be additionally arranged behind the reactor.
The running cost statistics for this example 1 are as follows:
the cost of the nutrient salt and the alkali liquor is about 0.1 yuan/m3(ii) a The adding amount of the methanol is about 300mg/L, the unit price is 1800 yuan/ton, and the cost of the methanol is 0.54 yuan/m3(ii) a The power consumption of the aeration fan, the stirrer and the pump is about 2kW/m3The unit price of the sewage is calculated as 0.7 yuan/kWh, and the electricity charge is 1.4 yuan/m3(ii) a The MBR membrane is replaced according to a 5-year replacement period, and the replacement cost is about 0.52 yuan/m3：
Total direct operating cost 0.1+0.54+1.4+ 0.52-2.56 yuan/m3。
Example 2
The sewage produced by a certain acrylonitrile device has the treatment capacity of 50m3The water quality of inlet water is COD:
3500mg/L, total nitrogen: 280mg/L, ammonia nitrogen: 80mg/L, NO3 --N: 12mg/l, acrylonitrile: 100mg/L, pyridines: 600 mg/L.
The treatment process and the reactor structure are shown in figure 1, and the adopted coupled membrane bioreactor (CCMBR) is a reinforced concrete structure.
And after the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank are respectively inoculated with sludge and domesticated for 2-4 weeks, acrylonitrile sewage sequentially enters the biological selection tank, the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank, and finally effluent is pumped out of an ultrafiltration membrane component of the membrane tank.
The biological selection tank is used as a hydrolysis acidification tank, acrylonitrile sewage is mixed with suspension liquid refluxed from the tail end of an anoxic activated sludge tank, the reflux is realized by adopting a submersible water impeller, the reflux ratio is 3, and the HRT is 8 hours; and adding phosphorus salt according to the ratio of C to P of 200:1, and adding alkali liquor to prepare the aerobic activated sludge pool with the pH value of 7.5-8.1.
The filling rate of the suspended filler in the suspended filler oxidation pond is 50 percent, and the SALR of the filler is 15g/m2D, specific surface area of suspended filler 500m2/m3Controlling DO at 5-6 mg/L; mixed liquor at the tail end of the suspended filler oxidation tank enters the aerobic activated sludge tank through the overflowing hole of the partition wall, and a filler intercepting grid is arranged on the overflowing hole.
The mixed liquid enters an aerobic activated sludge tank and then is mixed with sludge returned from a membrane tank, and the return ratio is 100%; the sludge concentration in the control tank is about 6gMLSS/L, the DO at the tail end is about 2mg/L, the removal load of organic matters is 0.20kgCOD/kgMLVSS.d, and the nitrification load is 0.04kgNH3-N/kgMLVSS.d。
Aerobic activated sludge pool endThe nitrate liquid at the end enters an anoxic activated sludge tank, and the denitrification rate is 0.85kgTN/m3D, adding methanol with the addition amount of about 800mg/L according to 4 times of the total nitrogen concentration of the inlet water, controlling DO below 0.5mg/L, and installing a submersible stirrer in the pool.
The effluent of the anoxic activated sludge tank flows into a membrane tank by gravity, and an immersed hollow ultrafiltration membrane component is arranged in the membrane tank. The membrane pool is designed to have the HRT of 4h and the flux of the ultrafiltration membrane of 15L/m2H, total area of MBR ultrafiltration membrane needed to be 3333m2MBR module membrane area 1500m according to standard2Each group, 3 groups of MBR components are needed in total, the MBR components are divided into 3 rows, each row has 1 group of MBR components, and the water yield of each row is 25m3A/h variable frequency controlled suction pump. The water quality of the outlet water of the ultrafiltration membrane is as follows: COD is less than or equal to 100mg/L, TN is less than or equal to 40mg/L, NH3N is less than or equal to 8mg/L, and other indexes meet the requirements of discharge Standard of pollutants for petrochemical industry GB 31571-2015. Setting 250 m3A/h sludge reflux pump and variable frequency control. And part of the residual sludge is discharged from the sludge pump outlet main pipe.
The acrylonitrile sewage contains higher COD which is not biochemically degradable, and if the COD is required to be less than or equal to 60mg/L, an ozone catalytic oxidation tank can be additionally arranged behind the reactor.
The running cost statistics for this example 2 are as follows:
the cost of the nutrient salt and the alkali liquor is about 0.25 yuan/m3(ii) a The adding amount of the methanol is about 800mg/L, the unit price is 1800 yuan/ton, and the methanol cost is 1.44 yuan/m3(ii) a The power consumption of the aeration fan, the stirrer and the pump is about 3.8kW/m3The unit price of the sewage is calculated as 0.7 yuan/kWh, and the electricity charge is 2.66 yuan/m3(ii) a The MBR membrane is replaced according to a 5-year replacement period, and the replacement cost is about 0.54 yuan/m3：
The total direct operating cost is 0.25+1.44+2.66+ 0.54-4.89 yuan/m3。
Example 3
The treatment capacity of certain coking wastewater is 100m3And h, after phenol sodium salt, liquid ammonia and cyanide are pre-recovered through dephenolization, ammonia evaporation and decyanation, the sewage quality is COD: 3000mg/L, ammonia nitrogen: 300mg/L, phenol: 300mg/L, cyanide: less than 20 mg/L.
The treatment process and the reactor structure are shown in figure 1, and the adopted coupled membrane bioreactor (CCMBR) is a reinforced concrete structure.
And after the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank are respectively inoculated with sludge and domesticated for 2-4 weeks, acrylic fiber sewage sequentially enters the biological selection tank, the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank, and finally discharged water is pumped out of an ultrafiltration membrane component of the membrane tank.
The biological selection tank is used as a hydrolysis acidification tank, the coking wastewater is mixed with a suspension liquid refluxed from the tail end of the anoxic activated sludge tank, a sewage pump is adopted to realize reflux, the reflux ratio is 4, and the HRT is 6 hours; and adding phosphorus salt according to the ratio of C to P of 200:1, and adding alkali liquor to prepare the aerobic activated sludge pool with the pH value of 7.5-8.1.
The effluent of the biological selection tank enters a suspended filler oxidation tank, the filling rate of suspended fillers in the tank is 55 percent, and the SALR is 25g/m2D, specific surface area of 800m2/m3Controlling DO at 4-5 mg/L; mixed liquor at the tail end of the suspended filler oxidation tank enters the aerobic activated sludge tank through the overflowing hole of the partition wall, and grid meshes are arranged on the overflowing hole to intercept fillers.
The mixed liquor enters an aerobic activated sludge tank and then is mixed with sludge reflowing from a membrane tank, the reflux ratio is controlled to be 100 percent, the sludge concentration is about 6.5g MLSS/L, the DO at the tail end is about 2mg/L, the organic matter removal load is designed to be 0.17kg COD/kg MLSS.d, and the nitrification load is 0.05kg NH3-N/kgMLSS.d。
Nitrate liquid at the tail end of the aerobic activated sludge tank enters an anoxic activated sludge tank, and denitrification load is 0.70kgTN/m3D, adding methanol about 800mg/L according to 4 times of the total nitrogen concentration of the inlet water, controlling DO below 0.5mg/L, and installing a submersible stirrer in the pool.
The effluent of the anoxic activated sludge tank flows into a membrane tank by gravity, and an immersed hollow ultrafiltration membrane component is arranged in the membrane tank. The Hydraulic Retention Time (HRT) of the membrane pool is 4h, and the flux of the ultrafiltration membrane is 17L/m2H, total area of MBR ultrafiltration membrane required to be 5882m2MBR module membrane area 750m according to standard2Each group, which needs 8 groups of MBR components and is divided into 4 rows, each row has 2 groups of MBR components, and each row is matched with one MBR component with the water yield of 35m3Variation of/hAnd (4) frequency suction pump. The water quality of the outlet water of the ultrafiltration membrane is as follows: COD is less than or equal to 80mg/L, TN is less than or equal to 20mg/L, NH3-N is less than or equal to 10mg/L, and the emission requirements of the emission standard of pollutants for coking chemical industry GB16171-2012 are met. Setting 2 stations of 100m3A/h sludge reflux pump and variable frequency control. And part of the residual sludge is discharged from the sludge pump outlet main pipe.
The running cost statistics for this example 3 are as follows:
the cost of the nutrient salt and the alkali liquor is about 0.2 yuan/m3(ii) a The adding amount of the methanol is about 800mg/L, the unit price is 1800 yuan/ton, and the methanol cost is 1.44 yuan/m3(ii) a The power consumption of the aeration fan, the stirrer and the pump is about 3.5kW/m3The unit price of the sewage is calculated as 0.7 yuan/kWh, and the electricity charge is 2.45 yuan/m3(ii) a The MBR membrane is replaced according to a 5-year replacement period, and the replacement cost is about 0.53 yuan/m3The total direct running cost is 0.2+1.44+2.45+ 0.53-4.62 yuan/m3。
Example 4
The treatment capacity of certain coal chemical industry wastewater is 400m3The water quality of the sewage from which the petroleum and the suspended substances are removed by coagulation air flotation or coagulation sedimentation is COD: 1500mg/L, ammonia nitrogen: 120mg/L, total nitrogen: 150mg/L, phenols: 100mg/L, cyanide: less than 10 mg/L.
The coupling membrane bioreactor (CCMBR) is of a reinforced concrete structure.
And after the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank are respectively inoculated with sludge and domesticated for 2-4 weeks, sewage sequentially enters the biological selection tank, the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank, and finally discharged water is pumped out of an ultrafiltration membrane component of the membrane tank.
The biological selection tank is used as a mixing pre-aeration tank, sewage is mixed with suspension liquid refluxed from the tail end of an aerobic activated sludge tank, the reflux is realized by adopting a submersible stirrer, the reflux ratio is 10, and the mixture is stirred and mixed by utilizing compressed air; and adding phosphorus salt according to the ratio of C to P of 200:1, and adding alkali liquor to prepare the aerobic activated sludge pool with the pH value of 7.5-8.1.
The effluent of the biological selection tank enters a suspended filler oxidation tank, the filling rate of suspended fillers in the tank is 40 percent, and the SALR is 20g/m2D, specific surface area of 800m2/m3Controlling DO at 4-5 mg/L; mixed liquor at the tail end of the suspended filler oxidation tank enters the aerobic activated sludge tank through the overflowing hole of the partition wall, and grid meshes are arranged on the overflowing hole to intercept fillers.
The mixed liquor enters an aerobic activated sludge tank and then is mixed with sludge flowing back from a membrane tank, the reflux ratio is controlled to be 50 percent, the sludge concentration is about 5gMLSS/L, the DO at the tail end is about 2mg/L, the removal load of organic matters is designed to be 0.16kgCOD/kgMLSS.d, and the nitrification load is 0.04kgNH3-N/kgMLSS.d。
Nitrate liquid at the tail end of the aerobic activated sludge tank enters an anoxic activated sludge tank, and denitrification load is 0.55kgTN/m3D, adding sodium acetate about 900mg/L according to 4 times of the total nitrogen concentration of the inlet water, controlling DO below 0.5mg/L, and installing a submersible stirrer in the pool.
The effluent of the anoxic activated sludge tank flows into a membrane tank by gravity, and an immersed hollow ultrafiltration membrane component is arranged in the membrane tank. The Hydraulic Retention Time (HRT) of the membrane pool is 4.5h, and the flux of the ultrafiltration membrane is 17L/m2H, total area of MBR ultrafiltration membrane required to be 23530m2MBR module membrane area 1500m according to standard216 groups of MBR components are required for each group, the MBR components are divided into 4 rows, each row comprises 4 groups of MBR components, and each row is matched with one MBR component with the water yield of 135m3A/h variable frequency suction pump. The water quality of the outlet water of the ultrafiltration membrane is as follows: COD is less than or equal to 60mg/L, TN is less than or equal to 30mg/L, NH3-N is less than or equal to 5mg/L, and the discharge requirement of the discharge Standard of pollutants for petrochemical industry GB31571-2015 is met. Setting 2 400m3A/h sludge reflux pump and variable frequency control. And part of the residual sludge is discharged from the sludge pump outlet main pipe.
The running cost statistics for this example 4 are as follows:
the cost of the nutrient salt and the alkali liquor is about 0.16 yuan/m3(ii) a The dosage of the sodium acetate is about 900mg/L, the unit price is 2500 yuan/ton, and the cost of the sodium acetate is 2.25 yuan/m3(ii) a The power consumption of the aeration fan, the stirrer and the pump is about 1.8kW/m3The unit price of the sewage is calculated as 0.7 yuan/kWh, and the electricity charge is 1.26 yuan/m3(ii) a The MBR membrane is replaced according to a 5-year replacement period, and the replacement cost is about 0.52 yuan/m3The total direct operating cost is 0.16+2.25+1.26+ 0.52-4.19 yuan/m3。
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, i.e., the technical scope of the present invention should be equivalent to the modifications and variations of the present invention.

Claims (6)

1. The utility model provides a toxic, high nitrogenous chemical industry sewage coupling membrane biological treatment reactor which characterized in that, including establishing ties in proper order:
the biological selection pool is used for adaptively screening microorganisms in the sewage treatment process and carrying out primary treatment on the sewage;
the suspended filler oxidation pond is used for enabling beneficial microorganisms to be implanted and propagated, and degrading characteristic pollutants in the sewage treated by the biological selection pond;
an aerobic activated sludge tank, which degrades organic matters and nitrifies ammonia nitrogen in the sewage treated by the suspended filler oxidation tank; an anoxic activated sludge tank, which enables denitrifying bacteria to quickly convert nitrate nitrogen into N2Escaping;
the membrane tank is used for separating sludge and water, discharging the sludge and the water respectively and playing a role in degrading the denitrification residual carbon source;
the biological selection tank is communicated with the suspended filler oxidation tank, the aerobic activated sludge tank and the anoxic activated sludge tank, and the biological selection tank is coupled with the suspended filler oxidation tank, the aerobic activated sludge tank, the anoxic activated sludge tank and the membrane tank to form an integrated membrane bioreactor;
the toxic and high-nitrogen chemical wastewater firstly enters the biological selection tank and is fully mixed with the suspension liquid which flows back from the tail end of the aerobic activated sludge tank or the anoxic activated sludge tank and the medicament which is added according to the requirement; wherein the reflux ratio of the sewage to the suspension is 2-10;
the sewage treated by the biological selection tank enters a suspended filler oxidation tank: the suspended filler oxidation pond is filled with suspended fillers with large specific surface area, a mesopore aerator is arranged at the bottom of the suspended filler oxidation pond, the dissolved oxygen amount is controlled to be more than 4mg/L, and a filler interception grid mesh is arranged at the outlet of the suspended filler oxidation pond;
the sewage flowing out of the suspended filler oxidation tank and the activated sludge flowing back from the membrane tank are mixed according to the ratio of (0.5-1): 1, mixing the sludge in an aerobic activated sludge tank provided with a microporous aerator, wherein the sludge concentration of the aerobic activated sludge tank is 5-8 g/L, and the dissolved oxygen amount is 2-3 mg/L;
nitrate state liquid discharged from the aerobic activated sludge tank enters an anoxic activated sludge tank provided with a submersible stirrer, methanol or sodium acetate or glucose is added as a carbon source according to the concentration 4 times of the total nitrogen concentration in the nitrate state liquid, and the dissolved oxygen is controlled to be less than 0.5 mg/L.
2. The toxic and high-nitrogen chemical wastewater coupling membrane biological treatment reactor as claimed in claim 1, wherein the effluent of the anoxic activated sludge tank enters a membrane tank, an immersed hollow membrane or flat membrane ultrafiltration membrane module is arranged in the membrane tank, and aerators are arranged at the bottom of the membrane tank and the bottom of the membrane module; and pumping the treated water out of a water outlet of the membrane component by using a water outlet pump, refluxing the activated sludge in the membrane tank to the aerobic activated sludge tank and/or the suspended filler oxidation tank by using a sludge reflux pump, and discharging part of the residual sludge out of the toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor.
3. The toxic and high-nitrogen chemical wastewater coupled membrane bioreactor of claim 1, wherein the integrated membrane bioreactor is a reinforced concrete water tank or a steel water tank.
4. The toxic and high-nitrogen chemical wastewater coupled membrane biological treatment reactor as claimed in claim 1, wherein the biological selection tank is a pre-aeration tank or a hydrolysis acidification tank.
5. The toxic and high-nitrogen chemical wastewater coupled membrane biological treatment reactor as claimed in claim 4, wherein the biological selection tank is a pre-aeration tank, suspension is refluxed from the tail end of the aerobic activated sludge tank, and a reflux device adopts an air lifter, a submersible water impeller or a sewage pump.
6. The toxic and high-nitrogen chemical wastewater coupled membrane biological treatment reactor as claimed in claim 4, wherein when the biological selection tank is a hydrolysis acidification tank, suspension liquid is refluxed from the tail end of the anoxic activated sludge tank, and a reflux device adopts a submersible water impeller or a sewage pump.
CN201910822254.4A 2019-09-02 2019-09-02 Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor Active CN110436630B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910822254.4A CN110436630B (en) 2019-09-02 2019-09-02 Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910822254.4A CN110436630B (en) 2019-09-02 2019-09-02 Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor

Publications (2)

Publication Number Publication Date
CN110436630A CN110436630A (en) 2019-11-12
CN110436630B true CN110436630B (en) 2021-11-19

Family

ID=68438815

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910822254.4A Active CN110436630B (en) 2019-09-02 2019-09-02 Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor

Country Status (1)

Country Link
CN (1) CN110436630B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111732275A (en) * 2020-06-25 2020-10-02 长春黄金研究院有限公司 Advanced treatment method for high-hardness cyanide-containing wastewater
CN114105292B (en) * 2020-08-27 2023-05-12 中国石油化工股份有限公司 Wastewater denitrification device and process and application
CN113354203A (en) * 2021-06-15 2021-09-07 广东新大禹环境科技股份有限公司 Biological treatment method for electroplating comprehensive wastewater
CN113603304A (en) * 2021-08-19 2021-11-05 华南理工大学 Three-sludge aerobic-hydrolysis-aerobic-membrane bioreactor and method
CN114436473B (en) * 2022-01-26 2023-03-21 北京铭泽源环境工程有限公司 Full-flow nylon 66 salt production wastewater treatment method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1439609A (en) * 2003-03-24 2003-09-03 深圳市金达莱环保有限公司 Bio-oxidation of ammonia-nitrogen in waste water from circuit board production
CN102115297A (en) * 2011-01-14 2011-07-06 中国环境科学研究院 Double-reflux denitrification membrane-bioreactor (MBR) process for treating dry acrylic fiber waste water
CN107963719A (en) * 2017-11-28 2018-04-27 贵州锦丰矿业有限公司 A kind of processing unit and method of high concentration rhodanate waste water

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1439609A (en) * 2003-03-24 2003-09-03 深圳市金达莱环保有限公司 Bio-oxidation of ammonia-nitrogen in waste water from circuit board production
CN102115297A (en) * 2011-01-14 2011-07-06 中国环境科学研究院 Double-reflux denitrification membrane-bioreactor (MBR) process for treating dry acrylic fiber waste water
CN107963719A (en) * 2017-11-28 2018-04-27 贵州锦丰矿业有限公司 A kind of processing unit and method of high concentration rhodanate waste water

Also Published As

Publication number Publication date
CN110436630A (en) 2019-11-12

Similar Documents

Publication Publication Date Title
CN110436630B (en) Toxic and high-nitrogen-content chemical sewage coupling membrane biological treatment reactor
CN105461061B (en) A kind of municipal sewage A2/ O- biology synchronous denitrification dephosphorizing device and method
US7972513B2 (en) Process for treating nitrogenous wastewater with simultaneous autotrophic denitrification, hetertrophic denitrification and COD removal
CN102633359B (en) Method for treating total nitrogen of nitrogen-containing chemical wastewater
CN102126810B (en) Parallel A2O-MBR denitrifying phosphorus removal method
CN110092536A (en) A kind of kitchen anaerobic digestion biogas slurry combined treatment process
CN108946944A (en) The method that short-cut denitrification promotes the removal of waste water total nitrogen
CN102040315A (en) Method for treating high ammonia nitrogen wastewater by two-stage A/O process
US20170066668A1 (en) Highly effective sewage treatment based on regulation and control of directed electron flow and apparatus thereof
CN100554195C (en) A kind of waste water treatment process and purposes to high-ammonia nitrogen low C/N ratio
CN109205954A (en) Light electrolysis catalysis oxidation, biochemical treatment high-concentration waste hydraulic art
CN108117158B (en) Rapid culture method of denitrified granular sludge
CN101823814A (en) Method and system of integrated denitrifying phosphorus and nitrogen removal
CN112225397A (en) Sewage treatment system and method based on double-sludge denitrification dephosphorization and biological filter tower
CN110171904B (en) Continuous flow AAO dephosphorization and partial denitrification series-connection combined type fixed biological membrane activated sludge autotrophic denitrification device and method
CN112093890B (en) Method for treating sewage by short-cut nitrification
CN107082492B (en) Low-consumption continuous flow domestic sewage treatment reactor and nitrogen and phosphorus efficient removal method
CN115367879B (en) Method for realizing urban sewage deep denitrification by anaerobic ammonia oxidation driven carrier biological film/suspended sludge system
CN109912126A (en) A kind of pesticides waste water treatment process
CN213680271U (en) Sewage treatment system based on two sludge denitrification dephosphorization and biological filter tower
CN114409082A (en) High-ammonia-nitrogen and low-carbon-nitrogen-ratio sewage wastewater OAO coupling zero-valent iron nitrogen and phosphorus removal method
CN114477456A (en) Endogenous short-cut denitrification enhanced municipal sewage short-cut nitrification/anaerobic ammonia oxidation deep denitrification device and method
CN210457854U (en) Mainstream autotrophic nitrogen removal system based on MBBR
CN112299561A (en) Landfill leachate short-cut nitrification and denitrification treatment method
CN115477390B (en) Process for treating garbage leachate by combining biological treatment and membrane assembly

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant