CN114426369A - Biochemical treatment method and device for benzo (a) pyrene in coking wastewater - Google Patents

Biochemical treatment method and device for benzo (a) pyrene in coking wastewater Download PDF

Info

Publication number
CN114426369A
CN114426369A CN202011024697.8A CN202011024697A CN114426369A CN 114426369 A CN114426369 A CN 114426369A CN 202011024697 A CN202011024697 A CN 202011024697A CN 114426369 A CN114426369 A CN 114426369A
Authority
CN
China
Prior art keywords
effluent
treatment
coagulating sedimentation
introducing
pyrene
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.)
Pending
Application number
CN202011024697.8A
Other languages
Chinese (zh)
Inventor
王珺
孙杰
付春雨
郦和生
龚小芝
曹宗仑
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.)
Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
Original Assignee
Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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 Sinopec Beijing Research Institute of Chemical Industry, China Petroleum and Chemical Corp filed Critical Sinopec Beijing Research Institute of Chemical Industry
Priority to CN202011024697.8A priority Critical patent/CN114426369A/en
Publication of CN114426369A publication Critical patent/CN114426369A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/28—Treatment of water, waste water, or sewage by sorption
    • C02F1/283—Treatment of water, waste water, or sewage by sorption using coal, charred products, or inorganic mixtures containing them
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/40—Devices for separating or removing fatty or oily substances or similar floating material
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5281—Installations for water purification using chemical agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
    • C02F1/56—Macromolecular compounds
    • 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
    • C02F2101/32—Hydrocarbons, e.g. oil
    • C02F2101/327—Polyaromatic Hydrocarbons [PAH's]
    • 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
    • C02F2209/22—O2
    • 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
    • C02F2209/44—Time
    • 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
    • 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
    • C02F3/02—Aerobic processes
    • C02F3/12—Activated sludge processes
    • C02F3/1236—Particular type of activated sludge installations
    • C02F3/1268—Membrane bioreactor systems
    • C02F3/1273—Submerged membrane bioreactors

Abstract

The invention discloses a biochemical treatment method and device for benzo (a) pyrene in coking wastewater. The method comprises S1, introducing the coking wastewater into a homogenizing adjusting device for homogenizing adjustment to obtain first effluent; s2, introducing the first effluent obtained in the step S1 into an oil separation device for oil separation treatment to obtain second effluent; s3, introducing the second effluent obtained in the step S2 into a coagulating sedimentation device for coagulating sedimentation treatment to obtain third effluent after coagulating sedimentation treatment; s4, introducing the third effluent obtained in the step S3 into a filtering device for filtering treatment to obtain fourth effluent after filtering treatment; s5, introducing the fourth effluent obtained in the step S4 into an MBR (membrane bioreactor) for biochemical reaction to obtain fifth effluent and activated sludge after reaction; and S6, introducing the fifth effluent obtained in the step S5 into an adsorption device for adsorption treatment. The device has the advantages of high concentration of activated sludge, simplified structure and small occupied area, and can reduce the production and manufacturing cost and the use and operation cost of the sewage treatment device containing benzo (a) pyrene.

Description

Biochemical treatment method and device for benzo (a) pyrene in coking wastewater
Technical Field
The invention belongs to the technical field of chemical industry and environmental protection, and particularly relates to a biochemical treatment method and device for benzo (a) pyrene in coking wastewater.
Background
Coking wastewater is a recognized industrial wastewater difficult to biodegrade, the difficulty lies in poor biodegradability of the wastewater, the wastewater contains phenols, heterocycles such as naphthalene, pyridine and quinoline and polycyclic aromatic compounds (PAHS) besides inorganic pollutants such as ammonia, cyanogen and thiocyanogen, and is difficult to biodegrade, and in addition, high-concentration ammonia nitrogen, sulfides and cyanides have strong inhibition effect on microbial activity, and the biological denitrification effect is poor. The benzo (a) pyrene (BaP) belongs to the first pollutant strictly controlled by the state, is mainly generated by high-temperature pyrolysis, cyclization and polymerization of carbonaceous substances such as coal, petroleum, firewood and the like, has strong carcinogenicity, and can directly threaten human health while causing serious environmental pollution. The benzo (a) pyrene has strict emission control standards in wastewater, and the emission standard of the benzo (a) pyrene is lower than 0.03 mu g/L in the standards of 31570-2015 in the refining industry. Because the concentration of benzo (a) pyrene in wastewater is low, the standard discharge is difficult to realize by using the conventional method for treatment. With the national higher and higher environmental protection requirements, how to treat the coking wastewater containing benzo (a) pyrene becomes a problem to be solved urgently in the coking industry.
At present, the domestic coking wastewater treatment generally adopts a two-stage treatment process of pretreatment and biochemical treatment, but benzo (a) pyrene in the wastewater after the conventional two-stage biological treatment is difficult to reach the standard. CN200810155656.5 reports a method for deeply treating benzo (a) pyrene in a drinking water source by a biological membrane, which is characterized by fusing protoplasts of three parent strains of eukaryotic prokaryotic cells of white rot fungi, indigenous bacteria YZ and saccharomyces cerevisiae, constructing genetic engineering bacteria through gene recombination and integration, and introducing the genetic engineering bacteria into a columnar reactor filled with an activated carbon carrier to remove the benzo (a) pyrene in the drinking water source. However, the process aims at trace benzo (a) pyrene in drinking water, and industrial wastewater is difficult to treat.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a biochemical treatment method of benzo (a) pyrene in coking wastewater. According to the method, coking wastewater containing benzo (a) pyrene is subjected to homogenization, oil separation and coagulating sedimentation, then enters an MBR (membrane bioreactor) for biochemical reaction to remove most organic matters including benzo (a) pyrene, and effluent after reaction enters an adsorption tower for further adsorption to remove benzo (a) pyrene, and then reaches the standard and is discharged. The method for treating the coking wastewater containing benzo (a) pyrene can effectively ensure that the first pollutant benzo (a) pyrene at the discharge outlet of the coking device is discharged up to the standard.
According to a first aspect, the biochemical treatment method of benzo (a) pyrene in coking wastewater provided by the invention comprises the following steps:
s1, introducing the coking wastewater into a homogenizing adjusting device for homogenizing adjustment to obtain first effluent;
s2, introducing the first effluent obtained in the step S1 into an oil separation device for oil separation treatment to obtain second effluent;
s3, introducing the second effluent obtained in the step S2 into a coagulating sedimentation device for coagulating sedimentation treatment to obtain third effluent after coagulating sedimentation treatment;
s4, introducing the third effluent obtained in the step S3 into a filtering device for filtering treatment to obtain fourth effluent after filtering treatment;
s5, introducing the fourth effluent obtained in the step S4 into an MBR (membrane bioreactor) for biochemical reaction to obtain fifth effluent and activated sludge after reaction;
and S6, introducing the fifth effluent obtained in the step S5 into an adsorption device for adsorption treatment to obtain sixth effluent.
According to some embodiments of the invention, the MBR membrane bioreactor comprises a bioreactor having activated sludge disposed therein and a membrane chamber having a membrane module disposed therein.
According to some embodiments of the invention, the membrane module is selected from one or more of a flat sheet membrane and a hollow fiber membrane.
According to some embodiments of the invention, the membrane of the membrane module is selected from one or more of a microfiltration membrane and an ultrafiltration membrane.
According to some embodiments of the invention, the membrane of the membrane module has a pore size of 0.005 to 0.2 μm.
According to some embodiments of the invention, the membrane module is a hollow fiber membrane, the membrane having a pore size of 0.01 to 0.2 μm.
According to some embodiments of the invention, the MBR membrane bioreactor further comprises an aeration device, preferably the aeration device is right below the membrane module, wastewater flows upwards along with airflow, the microbial filter cake layer on the surface of the hollow fiber membrane is loose, during the sewage treatment process, the shaking of the membrane filaments can be utilized to enable macromolecular particle impurities to flow back to a wastewater system along with concentrated solution, and the small biological molecules are adsorbed on the outer surface of the membrane to grow while being intercepted.
According to some embodiments of the invention, in S5, the fourth effluent is treated by activated sludge and then separated by a membrane module to obtain a fifth effluent and activated sludge after reaction.
According to some embodiments of the invention, the activated sludge is selected from activated sludge conventionally used in the art, such as sedimentation tank sludge or dewatered sludge.
In the invention, the MBR membrane bioreactor is a combined bioreactor of biological treatment and membrane interception, adopts membrane filtration to replace gravity separation, realizes effective separation of HRT and SRT, relieves the sludge loss problem of the traditional activated sludge process, simultaneously strengthens the microbial degradation capability, and is convenient to operate. The retention of COD by the membrane has two main aspects: firstly, due to the limitation of the membrane aperture, the particles larger than the membrane aperture are directly intercepted; and secondly, a filter cake layer is formed on the surface of the membrane along with the prolonging of time, and the filter cake layer plays a main role in intercepting the SS. When the sludge on the surface of the membrane is deposited to a certain degree, the absolute value of the effluent pressure is increased, and the membrane needs to be cleaned when the absolute value of the effluent pressure is increased to a certain value. The MBR membrane bioreactor has long sludge age and less residual sludge, and can efficiently intercept characteristic flora with slow growth rate, thereby degrading polycyclic aromatic hydrocarbon substances such as benzo (a) pyrene and the like.
According to some embodiments of the invention, the activated sludge after the reaction in S5 is returned to the coagulating sedimentation device of S3.
According to some embodiments of the present invention, 5-30% of the reacted activated sludge in S5 is returned to the coagulator of S3, for example, 7%, 12%, 15%, 17%, 20%, 23%, 27% and any value therebetween of the reacted activated sludge is returned to the coagulator of S3.
According to some embodiments of the invention, 10-25% of the reacted activated sludge in S5 is returned to the coagulating sedimentation device of S3.
In the invention, the residual sludge of the MBR membrane bioreactor can be partially refluxed to the coagulation tank before being mixed with the raw water added with the coagulant to enhance the treatment effect. The returned sludge increases more adsorption active sites, improves the adsorption capacity of the returned sludge, and has the functions of strengthening coagulation and saving dosage after the sludge is returned. On the one hand, the number of particles in raw water is increased by the return sludge, the electric neutralization and adsorption bridging in the coagulation process are strengthened, the probability of particle collision is improved, and the flocculation core is increased, so that colloid particles are more easily destabilized, destabilized colloid can form flocs better under the actions of net catching, rolling, sweeping and the like, and organic matters such as oil in water can be adsorbed, and the COD removal effect can be strengthened. On the other hand, the microorganisms in the sludge secrete a large amount of SMP and EPS coated zoogloea, so that the microorganisms can effectively resist the adverse effects of toxic substances in the wastewater. Meanwhile, the sludge backflow process can adsorb or degrade organic matters in suspended particles, and has good removal performance on soluble organic matters, because the sludge backflow improves the floc structure, the specific surface area of the flocs is increased, and the adsorption capacity of the flocs is improved.
According to some embodiments of the present invention, in S5, the activated sludge concentration is 3000-8000mg/L and the dissolved oxygen DO concentration is 2-6mg/L based on the volume of the coking wastewater.
According to some embodiments of the invention, the retention time of the fourth effluent in the MBR membrane bioreactor is 0.5-2d in S5.
According to some embodiments of the invention, one or more swash plates are provided in the oil barrier.
According to some embodiments of the invention, the inclined plate is at an angle of 30 to 45 degrees to the horizontal.
According to some embodiments of the invention, in S2, the residence time of the first effluent in the oil separator is 10-80min, such as 15min, 25min, 30min, 40min, 50min, 65min, 70min and any value in between.
According to some embodiments of the invention, in S2, the residence time of the first effluent in the oil separator is 20-60 min.
According to some embodiments of the invention, the oil content in the second effluent is less than 3mg/L in S2.
According to some embodiments of the invention, in S3, the second effluent is introduced into a coagulating sedimentation device to be mixed with a coagulating sedimentation agent for coagulating sedimentation, and the wastewater after coagulating sedimentation is separated to obtain a third effluent.
According to some embodiments of the invention, the coagulating sedimentation agent comprises a flocculating agent and a coagulant.
According to some embodiments of the invention, the flocculating agent is selected from one or more of the polymers of aluminium.
According to some embodiments of the invention, the flocculant is selected from polyaluminium chloride (PAC).
According to some embodiments of the invention, the coagulant aid is selected from one or more of polyacrylamide coagulant aids.
According to some embodiments of the invention, the coagulant aid is selected from Polyacrylamide (PAM).
According to some embodiments of the present invention, the flocculant is present in an amount of 50 to 150mg/L, such as 55mg/L, 65mg/L, 70mg/L, 80mg/L, 90mg/L, 95mg/L, 110mg/L, 120mg/L, 130mg/L and any value therebetween, based on the volume of the coking wastewater.
According to some embodiments of the invention, the flocculant is used in an amount of 60 to 100mg/L based on the volume of the coking wastewater.
According to some embodiments of the present invention, the coagulant aid is used in an amount of 1 to 15mg/L, such as 2mg/L, 3.5mg/L, 4mg/L, 5mg/L, 6mg/L, 7mg/L, 8mg/L, 9mg/L, 11mg/L, 12mg/L, 13mg/L and any value therebetween, based on the volume of the coking wastewater.
According to some embodiments of the present invention, the coagulant aid is used in an amount of 3 to 10mg/L based on the volume of the coking wastewater.
According to some embodiments of the invention, the adsorption unit is selected from an adsorption column having an adsorbent disposed therein.
According to some embodiments of the invention, the adsorbent is selected from activated carbon, such as powdered, granular activated carbon made from coal or coconut shells.
According to some embodiments of the invention, the residence time of the fifth effluent in the adsorption device is between 1 and 4 h.
According to the invention, the characteristics of the activated carbon, such as huge specific surface area, developed pore structure and excellent adsorption performance, are utilized to ensure that the effluent meets the discharge standard.
According to some preferred embodiments of the invention, the method comprises the following specific steps:
firstly, feeding the coking wastewater into a homogenizing and adjusting tank for homogenizing and adjusting;
secondly, the homogenized coking wastewater is introduced into an oil separation tank to remove scum and oil substances in the wastewater, and after oil separation treatment, the oil content in the wastewater is less than 3mg/L, so that the adverse effect of tar substances on subsequent biochemical units is eliminated;
thirdly, introducing the wastewater subjected to oil separation treatment into a coagulating sedimentation tank, adding a flocculating agent and a coagulant aid, mixing alum floc and return sludge, precipitating, and removing the benzo (a) pyrene adsorbed on the suspended matters by removing the suspended matters in the wastewater;
fourthly, filtering the supernatant after coagulating sedimentation, and then entering an MBR (membrane bioreactor) for biochemical reaction to remove most organic matters including benzo (a) pyrene, wherein the residual sludge can flow back to the front section of the coagulation tank to enhance the coagulation effect;
fifthly, enabling effluent of the MBR membrane bioreactor to enter an adsorption tower from the bottom, further adsorbing and removing benzo (a) pyrene by an adsorbent, and then discharging after reaching the standard.
According to some embodiments of the invention, the coking wastewater has a benzo (a) pyrene concentration of 0.04 to 90 μ g/L.
According to some embodiments of the invention, the coking wastewater has a COD concentration of 200-800 mg/L.
According to a second aspect, the present invention provides an apparatus for use in the method of the first aspect, comprising:
a homogeneity adjusting device;
the oil separation device is connected with the homogeneity adjusting device;
the coagulating sedimentation device is connected with the oil separation device;
the filtering device is connected with the coagulating sedimentation device;
the MBR membrane bioreactor is connected with the filtering device;
and the adsorption device is connected with the MBR membrane bioreactor.
According to some embodiments of the present invention, the homogeneity adjusting device is configured to perform homogeneity adjustment on the coking wastewater to obtain a first effluent after the homogeneity adjustment.
According to some embodiments of the invention, the oil separation device is configured to perform oil separation treatment on the first effluent to obtain a second effluent after the oil separation treatment.
According to some embodiments of the invention, one or more swash plates are provided in the oil barrier.
According to some embodiments of the invention, the inclined plate is at an angle of 30 to 45 degrees to the horizontal.
According to some embodiments of the present invention, the oil separation device is selected from an oil separation tank, preferably, the oil separation tank adopts an inclined plate to separate oil, and an inclined plate is additionally arranged in the horizontal flow sedimentation tank, wherein the angle of the inclined plate is 30-45 degrees.
According to some embodiments of the invention, the coagulating sedimentation device is used for coagulating sedimentation treatment of the second effluent to obtain a third effluent after coagulating sedimentation treatment.
According to some embodiments of the invention, the filtering device is configured to perform filtering treatment on the third effluent to obtain a filtered fourth effluent.
According to some embodiments of the invention, the filter device is a Y-filter.
According to some embodiments of the invention, the MBR membrane bioreactor is configured to perform biochemical treatment on the fourth effluent to obtain a treated fifth effluent.
According to some embodiments of the invention, the adsorption device is configured to perform an adsorption treatment on the fifth effluent to obtain a sixth effluent.
In some embodiments of the present invention, the apparatus comprises a homogenizing tank 1, an oil separation tank 3, a coagulating sedimentation tank 8, a Y-type filter 18, an MBR membrane bioreactor 19 and an adsorption tower 26 which are connected in sequence as shown in FIG. 1.
According to some embodiments of the invention, the MBR membrane bioreactor comprises two parts, a bioreactor chamber and a membrane chamber.
According to some embodiments of the present invention, as shown in fig. 1, the homogenizing tank 1 is connected to an inlet of a homogenizing tank lift pump 2 through a pipeline, an outlet of the homogenizing tank lift pump 2 is connected to an inlet 4 of an oil separation tank through a pipeline, an outlet 5 of the oil separation tank is connected to an inlet 9 of a coagulation sedimentation tank through a pipeline, an outlet 17 of the coagulation sedimentation tank is connected to a Y-type filter 18 through a pipeline, an outlet of the Y-type filter 18 is connected to an inlet 21 of an MBR reactor through a pipeline, and an MBR membrane group water pump 22 is connected to an inlet 27 of an adsorption tower through a pipeline.
The invention has the following beneficial effects:
(1) the membrane of the MBR membrane bioreactor has small membrane aperture, can intercept all sludge in the reactor, has good removal effect on benzo (a) pyrene attached to suspended matters, has high sludge concentration in the reactor, and improves the removal efficiency of the MBR membrane bioreactor on organic matters.
(2) The MBR membrane bioreactor can efficiently intercept characteristic flora with slow growth rate, degrade polycyclic aromatic hydrocarbons such as benzo (a) pyrene and the like, and ensure good effluent quality.
(3) The MBR membrane bioreactor operates under the conditions of high volume load, low sludge load and long sludge age, has low sludge yield and good biological population diversity, and can effectively resist the impact influence.
(4) The sludge backflow strengthening coagulation effect and the backflow sludge coagulation characteristic can strengthen the coagulation treatment effect, improve the removal of pollutants by coagulation sedimentation and reduce the discharge amount of residual sludge.
(5) The MBR membrane bioreactor adopts a membrane to carry out solid-liquid separation, and is less influenced by the sludge expansion problem.
Drawings
FIG. 1 is a schematic diagram of the apparatus of the present invention:
in fig. 1, a homogenizing tank, 2, a homogenizing tank lift pump, 3, an oil separation tank, 4, an oil separation tank inlet, 5, an oil separation tank outlet, 6, a coagulating agent tank, 7, an agent metering pump, 8, a coagulating sedimentation tank, 9, a coagulating sedimentation tank inlet, 10, a coagulating area, 11, a hollow rotating shaft, 12, a stirring blade, 13, a partition plate, 14, a sedimentation area, 15, a sludge discharge port, 16, an overflow weir, 17, a coagulating sedimentation tank outlet, 18, a Y-shaped filter, 19, an MBR tank, 20, a membrane group, 21, an MBR tank inlet, 22, a water production pump, 23, a reflux liquid outlet, 24, a gas distribution pipe, 25, a gas pump, 26, an adsorption tower, 27, an adsorption tower inlet, 28, an adsorbent, 29 and an adsorption tower outlet.
Detailed Description
The invention provides a biochemical treatment method of benzo (a) pyrene in coking wastewater, which comprises the following process flows of:
after being homogenized in a homogenizing tank 1, the coking wastewater is sent to an oil separation tank 3 through a homogenizing tank lifting pump 2, tar in the wastewater is separated and removed, and scum is discharged; the water discharged from the oil separation tank 3 is sent to a coagulating sedimentation tank 8, and is mixed with a coagulating agent under the action of a stirring paddle, and alum blossom precipitate is discharged from a sludge discharge port; the effluent of the coagulation sedimentation tank 8 is discharged through an overflow weir 16, and the effluent enters an MBR (membrane bioreactor) 19 after being filtered again through a Y-shaped filter 18; the wastewater is subjected to biochemical reaction in the MBR membrane bioreactor to remove most organic matters including benzo (a) pyrene, the effluent after reaction is discharged through the water production pump 22, the effluent enters the adsorption tower 26, and after the benzo (a) pyrene in the wastewater is further removed through adsorption of the adsorbent, the wastewater is discharged after reaching the standard.
The invention provides a biochemical treatment device for benzo (a) pyrene in coking wastewater, which comprises a homogenizing tank 1, an oil separation tank 3, a coagulating sedimentation tank 8, a Y-shaped filter 18, an MBR (membrane bioreactor) 19 and an adsorption tower 26 which are sequentially connected as shown in figure 1. Homogeneity pond 1 passes through the pipe connection with 2 imports of homogeneity pond elevator pump, 2 exports of homogeneity pond elevator pump and oil interceptor import 4 passes through the tube coupling, oil interceptor export 5 passes through the tube coupling through pipeline and coagulating sedimentation tank import 9, coagulating sedimentation tank export 17 passes through the tube coupling with Y type filter 18, Y type filter 18 goes out water and passes through the tube coupling with MBR membrane bioreactor import 21, and MBR membrane group product water pump 22 passes through the tube coupling with adsorption tower import 27.
The present invention is further illustrated by the following examples, which are intended to be purely exemplary of the invention and are not to be construed as limiting the invention in any way.
The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
The first embodiment is as follows: in a certain refinery, the concentration of benzo (a) pyrene in a discharge port of a coking device is 60 mug/L, COD to be 600mg/L, and in order to meet the requirement that the concentration of benzo (a) pyrene in the discharge port of the device is less than 0.03 mug/L, the biochemical process is adopted for treatment, the final effluent concentration of benzo (a) pyrene is 0.03 mug/L, and the COD effluent concentration is 50 mg/L.
The process flow is as follows:
(1) after being homogenized in a homogenizing tank 1, the coking wastewater is sent to an oil separation tank 3 through a homogenizing tank lifting pump 2, tar in the wastewater is separated and removed, and scum is discharged;
(2) the water discharged from the oil separation tank 3 is sent to a coagulating sedimentation tank 8, and is mixed with a coagulating agent under the action of a stirring paddle, and alum blossom precipitate is discharged from a sludge discharge port; the effluent of the coagulation sedimentation tank 8 is discharged through an overflow weir 16,
(3) the effluent is filtered again by the Y-shaped filter 18 and then enters the MBR (membrane bioreactor) 19;
(4) the wastewater is subjected to biochemical reaction in an MBR (membrane bioreactor) to remove most organic matters including benzo (a) pyrene, the activated sludge after the reaction flows back to the front section of the coagulation tank, the effluent after the reaction is discharged through a water producing pump 22,
(5) and (3) the effluent enters an adsorption tower 26, and is subjected to adsorption by an adsorbent to further remove benzo (a) pyrene in the wastewater, so that the effluent is discharged after reaching the standard.
The device settings and process parameter ranges are as follows:
(1) the retention time of the oil separation tank is 40 min;
(2) the coagulating agent comprises PAC and PAM, wherein the dosage of PAC is added according to 90mg per liter of wastewater, and the dosage of PAM is added according to 10mg per liter of wastewater;
(3) the total retention time of the MBR membrane bioreactor is 1.5d, the mass concentration of the sludge is 5000mg/L, the DO is 5mg/L, the membrane group form is a hollow fiber membrane, the aperture is 0.1-0.2 mu m, and 20 percent of the activated sludge after reaction flows back to the front section of the coagulation tank;
(4) the adsorption tower is filled with powdered activated carbon, and the retention time is 1.5 h.
Comparative example one: taking certain industrial wastewater, namely benzo (a) pyrene with the concentration of 60 mu g/L and COD of 600 mg/L. The mixed wastewater is treated by the same device as in example 1, but no sludge backflow process is adopted, the mixed wastewater achieves the effect of the first example, the mixed PAC consumption is increased by 30%, and the used time is increased by 20%.
Example two: in a certain refinery, the concentration of benzo (a) pyrene in a discharge port of a coking device is 40 mug/L, COD to be 500mg/L, and in order to meet the requirement that the concentration of benzo (a) pyrene in the discharge port of the device is less than 0.03 mug/L, the biochemical process is adopted for treatment, the final effluent concentration of benzo (a) pyrene is 0.03 mug/L, and the COD effluent concentration is 40 mg/L.
The process flow is as follows:
(1) after being homogenized in a homogenizing tank 1, the coking wastewater is sent to an oil separation tank 3 through a homogenizing tank lifting pump 2, tar in the wastewater is separated and removed, and scum is discharged;
(2) the water discharged from the oil separation tank 3 is sent to a coagulating sedimentation tank 8, and is mixed with a coagulating agent under the action of a stirring paddle, and alum blossom precipitate is discharged from a sludge discharge port; the effluent of the coagulation sedimentation tank 8 is discharged through an overflow weir 16,
(3) the effluent is filtered again by the Y-shaped filter 18 and then enters the MBR (membrane bioreactor) 19;
(4) the wastewater is subjected to biochemical reaction in an MBR (membrane bioreactor) to remove most organic matters including benzo (a) pyrene, the activated sludge after the reaction flows back to the front section of the coagulation tank, the effluent after the reaction is discharged through a water producing pump 22,
(5) and (3) the effluent enters an adsorption tower 26, and is subjected to adsorption by an adsorbent to further remove benzo (a) pyrene in the wastewater, so that the effluent is discharged after reaching the standard.
The device settings and process parameter ranges are as follows:
(1) the retention time of the oil separation tank is 30 min;
(2) the coagulating agent comprises PAC and PAM, wherein the dosage of PAC is added according to 70mg per liter of wastewater, and the dosage of PAM is added according to 5mg per liter of wastewater;
(3) the total retention time of the MBR membrane bioreactor is 1d, the mass concentration of the sludge is 4000mg/L, the DO is 4mg/L, the membrane group is a hollow fiber membrane, and 10 percent of the activated sludge after reaction flows back to the front section of the coagulation tank;
(4) the adsorption tower is filled with granular activated carbon, and the retention time is 3 hours.
Comparative example two: taking certain industrial wastewater, namely benzo (a) pyrene with the concentration of 40 mu g/L and COD of 500 mg/L. Unlike example 2, the removal rate of benzo (a) pyrene was reduced by 30% without a coagulation apparatus.
Example three: taking the concentration of benzo (a) pyrene in certain industrial wastewater as 60 mu g/L, COD as 600 mg/L. Different from the embodiment 1, 22 percent of the activated sludge after reaction flows back to the front section of the coagulation tank, the benzo (a) pyrene in the treated water can be reduced from 60 mu g/L to 0.02 mu g/L, and the COD is reduced from 600mg/L to 40 mg/L.
Example four: taking the concentration of benzo (a) pyrene in certain industrial wastewater as 60 mu g/L, COD as 600 mg/L. Different from the embodiment 1, 25 percent of the activated sludge after reaction flows back to the front section of the coagulation tank, the benzo (a) pyrene in the treated water can be reduced from 60 mu g/L to 0.01 mu g/L, and the COD is reduced from 600mg/L to 35 mg/L.
Example five: taking the concentration of benzo (a) pyrene in certain industrial wastewater as 60 mu g/L, COD as 600 mg/L. Different from the example 1, 35 percent of the activated sludge after reaction flows back to the front section of the coagulation tank, the benzo (a) pyrene in the treated water can be reduced from 60 mu g/L to 0.005 mu g/L, and the COD is reduced from 600mg/L to 33 mg/L.
Any numerical value mentioned in this specification, if there is only a two unit interval between any lowest value and any highest value, includes all values from the lowest value to the highest value incremented by one unit at a time. For example, if it is stated that the amount of a component, or a value of a process variable such as temperature, pressure, time, etc., is 50 to 90, it is meant in this specification that values of 51 to 89, 52 to 88 … …, and 69 to 71, and 70 to 71, etc., are specifically enumerated. For non-integer values, units of 0.1, 0.01, 0.001, or 0.0001 may be considered as appropriate. These are only some specifically named examples. In a similar manner, all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be disclosed in this application.
It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims (10)

1. A biochemical treatment method of benzo (a) pyrene in coking wastewater comprises the following steps:
s1, introducing the coking wastewater into a homogenizing adjusting device for homogenizing adjustment to obtain first effluent;
s2, introducing the first effluent obtained in the step S1 into an oil separation device for oil separation treatment to obtain second effluent;
s3, introducing the second effluent obtained in the step S2 into a coagulating sedimentation device for coagulating sedimentation treatment to obtain third effluent after coagulating sedimentation treatment;
s4, introducing the third effluent obtained in the step S3 into a filtering device for filtering treatment to obtain fourth effluent after filtering treatment;
s5, introducing the fourth effluent obtained in the step S4 into an MBR (membrane bioreactor) for biochemical reaction to obtain fifth effluent and activated sludge after reaction;
and S6, introducing the fifth effluent obtained in the step S5 into an adsorption device for adsorption treatment to obtain sixth effluent.
2. The method according to claim 1, wherein in S5, the MBR membrane bioreactor comprises a bioreactor and a membrane chamber, the bioreactor is provided with activated sludge, and the membrane chamber is provided with a membrane module;
preferably, the membrane module is selected from one or more of flat sheet membranes and hollow fiber membranes, preferably the membrane of the membrane module is selected from one or more of microfiltration membranes and ultrafiltration membranes, and/or the pore size of the membrane module is 0.005-0.2 μm.
3. The method according to claim 2, wherein in S5, the fourth effluent is treated by activated sludge and then separated by a membrane module to obtain fifth effluent and reacted activated sludge, preferably, the reacted activated sludge in S5 is returned to the coagulating sedimentation device of S3, preferably, 5-30%, preferably 10-25% of the reacted activated sludge is returned to the coagulating sedimentation device of S3.
4. The method according to claim 2 or 3, wherein in S5, the concentration of the activated sludge is 3000-8000mg/L and the DO concentration is 2-6mg/L based on the volume of the coking wastewater;
and/or the retention time of the fourth effluent in the MBR membrane bioreactor is 0.5-2 d.
5. The method according to any one of claims 1 to 4, wherein in S2, one or more inclined plates are arranged in the oil separator, preferably the inclined plates are at an angle of 30-45 degrees with the horizontal direction;
and/or the residence time of the first effluent in the oil separator is 10-80min, preferably 20-60 min; and/or the oil content in the second effluent is less than 3 mg/L.
6. The method according to any one of claims 1 to 5, wherein in S3, the second effluent is introduced into a coagulating sedimentation device to be mixed with a coagulating sedimentation agent for coagulating sedimentation, and the wastewater after coagulating sedimentation is separated to obtain a third effluent;
preferably, the coagulating sedimentation agent comprises a flocculating agent and a coagulant, more preferably, the flocculating agent is selected from one or more of polymers of aluminium, preferably from polyaluminium chloride, and/or the coagulant aid is selected from one or more of polyacrylamide coagulant aids, preferably from polyacrylamide;
further preferably, the dosage of the flocculating agent is 50-150mg/L, preferably 60-100mg/L and/or the dosage of the coagulant aid is 1-15mg/L, preferably 3-10mg/L based on the volume of the coking wastewater.
7. The method according to any one of claims 1 to 6, wherein in S6, the adsorption device is selected from an adsorption tower, an adsorbent is arranged in the adsorption tower, and preferably, the adsorbent is selected from activated carbon;
and/or the retention time of the fifth effluent in the adsorption device is 1-4 h.
8. The method according to any one of claims 1 to 7, wherein the coking wastewater has a benzo (a) pyrene concentration of 0.04 to 90 μ g/L and a COD concentration of 200 to 800 mg/L.
9. An apparatus for use in the method of any one of claims 1-8, comprising:
a homogeneity adjusting device;
the oil separation device is connected with the homogeneity adjusting device;
the coagulating sedimentation device is connected with the oil separation device;
the filtering device is connected with the coagulating sedimentation device;
the MBR membrane bioreactor is connected with the filtering device;
and the adsorption device is connected with the MBR membrane bioreactor.
10. The device of claim 9, wherein the homogeneity adjusting device is used for carrying out homogeneity adjustment on the coking wastewater to obtain first effluent after the homogeneity adjustment;
the oil separation device is used for carrying out oil separation treatment on the first effluent to obtain second effluent after the oil separation treatment;
the coagulating sedimentation device is used for carrying out coagulating sedimentation treatment on the second effluent to obtain third effluent after coagulating sedimentation treatment;
the filtering device is used for filtering the third effluent to obtain filtered fourth effluent;
the MBR membrane bioreactor is used for performing biochemical treatment on the fourth effluent to obtain treated fifth effluent;
and the adsorption device is used for carrying out adsorption treatment on the fifth effluent to obtain sixth effluent.
CN202011024697.8A 2020-09-25 2020-09-25 Biochemical treatment method and device for benzo (a) pyrene in coking wastewater Pending CN114426369A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011024697.8A CN114426369A (en) 2020-09-25 2020-09-25 Biochemical treatment method and device for benzo (a) pyrene in coking wastewater

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011024697.8A CN114426369A (en) 2020-09-25 2020-09-25 Biochemical treatment method and device for benzo (a) pyrene in coking wastewater

Publications (1)

Publication Number Publication Date
CN114426369A true CN114426369A (en) 2022-05-03

Family

ID=81309453

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011024697.8A Pending CN114426369A (en) 2020-09-25 2020-09-25 Biochemical treatment method and device for benzo (a) pyrene in coking wastewater

Country Status (1)

Country Link
CN (1) CN114426369A (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101624252A (en) * 2009-08-06 2010-01-13 江苏省环境科学研究院 Efficient treatment process for printing and dyeing waste water
CN103304095A (en) * 2013-05-27 2013-09-18 内蒙古包钢钢联股份有限公司 Treatment method for improving removal rate of benzo (a) pyrene in coking wastewater
CN105836966A (en) * 2016-05-11 2016-08-10 北京迅世达环保科技有限公司 High-concentration organic wastewater treatment process technology
CN206607129U (en) * 2017-03-22 2017-11-03 云南省环境科学研究院(中国昆明高原湖泊国际研究中心) A kind of apparatus for treating carbonized waste water
CN108373247A (en) * 2018-05-14 2018-08-07 北京赛科康仑环保科技有限公司 One kind being used for coking wastewater deep treatment reuse technology
CN209010346U (en) * 2018-10-17 2019-06-21 山西金承环境工程有限公司 A kind of in line processing equipment of coking wastewater

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101624252A (en) * 2009-08-06 2010-01-13 江苏省环境科学研究院 Efficient treatment process for printing and dyeing waste water
CN103304095A (en) * 2013-05-27 2013-09-18 内蒙古包钢钢联股份有限公司 Treatment method for improving removal rate of benzo (a) pyrene in coking wastewater
CN105836966A (en) * 2016-05-11 2016-08-10 北京迅世达环保科技有限公司 High-concentration organic wastewater treatment process technology
CN206607129U (en) * 2017-03-22 2017-11-03 云南省环境科学研究院(中国昆明高原湖泊国际研究中心) A kind of apparatus for treating carbonized waste water
CN108373247A (en) * 2018-05-14 2018-08-07 北京赛科康仑环保科技有限公司 One kind being used for coking wastewater deep treatment reuse technology
CN209010346U (en) * 2018-10-17 2019-06-21 山西金承环境工程有限公司 A kind of in line processing equipment of coking wastewater

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
尹儿琴等, 中国海洋大学出版社 *

Similar Documents

Publication Publication Date Title
WO2009124426A1 (en) A method for treating pharmaceutical mixed wastewater in chemical industry park
CN202322568U (en) Deep treatment system of high-concentration percolate of integrated garbage treatment site
CN102503046A (en) Advanced treatment system and method for high-concentration percolate in comprehensive garbage disposal plant
CN1792894A (en) Process for treating yellow ginger saponin waste water by hydrochloric acid method
KR100957851B1 (en) Method of water treatment
CN101880103A (en) Printing-dying wastewater recycling treatment process
CN111233285A (en) Integrated sewage purification and upgrading process
CN101746920A (en) Process for recycling and processing expandable polystyrene wastewater
KR20080051863A (en) Waste water of food treatment apparatus and using the method
CN113277684A (en) Method for removing organic matters in shale gas wastewater
CN216236438U (en) Pretreatment system for garbage extrusion leachate
CN111892235A (en) High-efficient degradation waste water zero discharge system
CN216808506U (en) Kitchen and kitchen garbage and wastewater treatment system
CN110540337A (en) novel efficient treatment method for landfill leachate
CN114426369A (en) Biochemical treatment method and device for benzo (a) pyrene in coking wastewater
CN211445406U (en) Landfill leachate treatment device
CN112960857A (en) Treatment process of landfill leachate
CN117088579B (en) Non-membrane method full-quantization treatment method for landfill leachate
CN216236576U (en) Efficient treatment system for garbage squeezing water
CN220845729U (en) Graphene oxide reinforced membrane bioreactor
CN214829766U (en) Traditional Chinese medicine wastewater treatment system difficult to biochemically treat
CN214360834U (en) Sewage treatment system and landfill leachate treatment integrated system
CN220335004U (en) Lithium iron phosphate production wastewater treatment system
CN219752071U (en) Biochemical tail water denitrification disinfection integration equipment of plant
CN112520911B (en) Landfill leachate concentrated water treatment method

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
RJ01 Rejection of invention patent application after publication

Application publication date: 20220503

RJ01 Rejection of invention patent application after publication