CN115947480A - Industrial wastewater treatment process and system based on multistage precipitation - Google Patents
Industrial wastewater treatment process and system based on multistage precipitation Download PDFInfo
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Abstract
The invention discloses a method based onThe industrial wastewater sequentially passes through a regulating tank, an anaerobic tank, a primary sedimentation tank and an ozone contact tank, domestic sewage passes through a coarse grid and a lifting pump station and then enters a fine grid and a grit chamber, and the domestic sewage and the industrial wastewater after oxidative decomposition form mixed wastewater; the mixed wastewater sequentially enters an AAO tank, an MBR tank and a disinfection tank, passes through a metering tank and is discharged after reaching the standard; and the sludge in the primary sedimentation tank and the sludge in the MBR tank enter a sludge concentration tank for concentration and enter a sludge conditioning tank, the sludge enters a sludge dewatering machine room after being conditioned, and the dewatered sludge is transported outside. The scale of the mixed sewage treatment method can reach 5 ten thousand meters 3 D, wherein the industrial wastewater is 3.2 ten thousand meters 3 D, domestic sewage 1.8 ten thousand meters 3 And d, the effluent quality reaches the first grade A standard of pollutant discharge Standard of municipal wastewater treatment plant (GB 18918-2002).
Description
Technical Field
The invention relates to the technical field of sewage treatment, in particular to an industrial wastewater treatment process and system based on multistage sedimentation.
Background
Sewage treatment: the sewage is purified to reach the water quality requirement of being discharged into a certain water body or being reused. Sewage treatment is widely applied to various fields such as buildings, agriculture, traffic, energy, petrifaction, environmental protection, urban landscape, medical treatment, catering and the like, and is increasingly used in daily life of common people.
The sewage treatment is generally classified into production sewage treatment and domestic sewage treatment according to the sewage source. The production sewage comprises industrial sewage, agricultural sewage, medical sewage and the like, and the domestic sewage is sewage generated in daily life, and refers to complex mixtures of various forms of inorganic matters and organic matters, and comprises the following steps: (1) floating and suspended large and small solid particles; (2) colloidal and gelatinous dispersions; (3) pure solution. The sewage treatment can be divided into a physical method, a biological method and a chemical method according to the functions of the sewage treatment. (1) Physical method: mainly utilizes physical action to separate non-soluble substances in the sewage, and does not change chemical properties in the treatment process. Gravity separation, centrifugal separation, reverse osmosis, air flotation, etc. are commonly used. The physical method is simple and economical in treating the structure, and is used for the conditions of large water volume of villages and towns, strong self-purification capacity and low requirement on sewage treatment degree. (2) The biological method comprises the following steps: by utilizing the metabolism function of microorganisms, the organic matters in a dissolved or colloidal state in the sewage are decomposed and oxidized into stable inorganic substances, so that the sewage is purified. Commonly used are an activated sludge process and a biofilm process. The biological method has higher treatment degree than the physical method. (3) The chemical method comprises the following steps: the method is a method for treating or recovering dissolved substances or colloidal substances of sewage by utilizing chemical reaction, and is mainly used for industrial wastewater. Coagulation, neutralization, redox, ion exchange, and the like are generally used. The chemical treatment method has good treatment effect and high cost, is mainly used for effluent after biochemical treatment and further treatment, and improves the effluent quality. At present, three methods are combined together to treat sewage.
The existing mixed sewage treatment method is only suitable for industrial sewage and common domestic wastewater, and the existing sewage treatment system cannot effectively treat domestic sewage of residents in mining areas around an industrial area and pithead water of a coal industrial area. The patent CN110981090B discloses a domestic sewage treatment device and a method for a coal mine industrial square, which comprises a fluidized bed biological treatment unit, a fixed bed biological treatment unit and a diatomite reinforced membrane treatment unit; the fluidized bed biological treatment unit is provided with a water inlet pipe, a water outlet pipe A, an aeration pipe A, a fluidized carrier B, an upper interception net A, a middle interception net and a lower interception net A; the fixed bed biological treatment unit is provided with an aeration pipe B, a water outlet pipe B, a carbon source adding device, a fixed carrier, an upper interception net B and a lower interception net B; the diatomite strengthening membrane processing unit is provided with a membrane component, a water production pipe, an aeration pipe C, a sludge discharge pipe and a diatomite feeding device. Although the domestic sewage in mining areas can be treated, the treatment scale is small, the treatment effect on the sewage is poor, and the pit water in coal industrial areas cannot be effectively treated.
Disclosure of Invention
In view of the above prior art, the present invention aims to provide an industrial wastewater treatment process and system based on multi-stage precipitation.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides an industrial wastewater treatment process based on multistage precipitation, which comprises the following steps:
(1) Industrial wastewater enters an anaerobic tank through a regulating tank, a medicament is added into the anaerobic tank, the industrial wastewater enters a primary sedimentation tank for sedimentation after reaction, the precipitated sludge flows back to the anaerobic tank, the precipitated industrial wastewater enters an ozone contact tank, a carbon source is added into the ozone contact tank, and the industrial wastewater is subjected to oxidative decomposition;
(2) Domestic sewage passes through the coarse grid and the lifting pump station and then enters the fine grid and the grit chamber, and the domestic sewage and the oxidized and decomposed industrial wastewater form mixed wastewater;
(3) The mixed wastewater enters an AAO tank, a carbon source is added into the AAO tank, the mixed wastewater enters an MBR tank after reaction, liquid in the MBR tank flows back to the AAO tank, the mixed wastewater after reaction in the MBR tank enters a disinfection tank and is disinfected by sodium hypochlorite, and the mixed wastewater passes through a metering tank and is discharged after reaching the standard;
(4) And (3) the sludge in the primary sedimentation tank and the sludge in the MBR tank enter a sludge concentration tank for concentration, the concentrated sludge enters a sludge conditioning tank, a conditioning agent is added into the sludge conditioning tank, the conditioned sludge enters a sludge dewatering machine room, and the dewatered sludge is transported outside.
Preferably, in step (1), the agent added is Polyacrylamide (PAM) per 5000m 3 1kg of polyacrylamide was added to the wastewater.
Preferably, in the step (1), the reflux ratio of the primary sedimentation tank is 100%.
Preferably, in the step (3), the carbon source added is glucose, and 250kg of glucose is added per ton of wastewater.
Preferably, in the step (3), the reflux ratio of the MBR tank is 300%.
Preferably, in step (3), sodium hypochlorite is added in an amount of 11 to 12 tons/day.
Preferably, in step (4), the conditioning agent is polyaluminum chloride with a dosage of 5000m 3 10kg of polyaluminium chloride was added to the waste water.
The invention provides an industrial wastewater treatment system based on multistage sedimentation, which comprises an adjusting tank, an anaerobic tank, a primary sedimentation tank, an ozone contact tank, an AAO tank, an MBR tank, a disinfection tank and a metering tank which are sequentially connected, wherein the AAO tank is also sequentially connected with a sand sedimentation tank and a lifting pump station, the primary sedimentation tank and the MBR tank are connected with a sludge concentration tank, and the sludge concentration tank is sequentially connected with a sludge conditioning tank and a sludge dewatering machine room.
Preferably, the grit chamber is provided with a fine grid, and the lifting pump station is provided with a coarse grid.
The scale of the mixed sewage treatment method can reach 5 ten thousand meters 3 /d，Wherein the industrial wastewater is 3.2 ten thousand meters 3 D, domestic sewage 1.8 ten thousand meters 3 And d, the effluent quality reaches the first grade A standard of pollutant discharge Standard of municipal wastewater treatment plant (GB 18918-2002).
The industrial wastewater passes through the regulating tank to be primarily precipitated, then enters the anaerobic tank, and is added with the medicament, the hydraulic retention time of the anaerobic tank is prolonged to 25 hours, and only the water body can really achieve water body acidification, organic matter separation and harmful substance molecule cracking in the water body, and the chromophoric groups of chromaticity can be cracked and decomposed, so that a decolorant or an oxidant does not need to be additionally added at a discharge section. The method not only saves the operation cost, but also ensures that the discharged sewage has no rebound chroma at all, namely the discharged sewage does not change color even if the discharged sewage is stored for tens of days in the sun. The method has the advantages that SS in the sewage can be reduced by about 30% under anaerobic conditions, and the sludge production is reduced.
The industrial wastewater enters a primary sedimentation tank for sedimentation after the reaction in the anaerobic tank. After the anaerobic sedimentation, a primary sedimentation tank and anaerobic sludge backflow are added, anaerobic microbial flora is thoroughly separated from sludge of a subsequent AAO system, sufficient and well-grown anaerobic microbial flora is ensured in the anaerobic tank, the decomposition and removal effects of the anaerobic sedimentation on organic matters difficult to biochemically degrade are improved, the micelle sedimentation performance of the anaerobic sludge is improved, and the anaerobic sludge is intercepted in the anaerobic tank through mud-water separation. Meanwhile, a large amount of non-biochemical harmful substances and substances which are difficult to decompose biochemically in a short time exist in the sludge (SS), so that the primary sedimentation tank is arranged, the impact load on the biochemical tank is reduced, and the removal rate of the biochemical tank is improved. The settled sludge flows back to the anaerobic tank, the effluent after anaerobic settlement enters a subsequent AAO system, and the settled anaerobic sludge does not enter the biochemical tank system, so that the impact on the subsequent AAO system is reduced, and the removal rate of the biochemical tank is improved.
And (4) the precipitated industrial wastewater enters an ozone contact tank, a carbon source is added into the ozone contact tank, and the industrial wastewater is subjected to oxidative decomposition. The oxidation process in which hydroxyl radicals are the main oxidants in the water treatment process is called AOPs process, i.e. advanced oxidation technique, and the E DEG of OH is2.8eV, second only to F (2.87 eV), is the strongest oxidant existing in nature, reacts with all pollutants in the wastewater almost without selectivity, and thoroughly oxidizes the organic matters which cannot be oxidatively decomposed by the conventional oxidant, ozone and chlorine into CO 2 And H 2 O。O 3 OH is generated under the action of the catalyst, so that the degradation of pollutants is rapid and sufficient, and meanwhile, the technology does not generate secondary pollution; a single oxygen atom 3 The direct oxidation reaction has selectivity, can not thoroughly degrade all organic pollutants in the wastewater, and has incomplete degradation and unstable water outlet effect. The ozone catalytic advanced oxidation technology improves the ozone gas dissolving efficiency on the basis of the advanced oxidation technology and effectively reduces the ozone adding amount. The ozone catalytic advanced oxidation technology is verified by a plurality of large-scale engineering performances, and the ozone adding amount is reduced, so that the technology is mature, the investment is reasonable, and the operating cost is low. The high-efficiency ozone gas dissolving system of the ozone catalytic advanced oxidation technology changes the microscopic substance form of sewage molecules by utilizing the electromagnetic effect, achieves the purposes of improving the dissolving efficiency of ozone gas and effectively reducing the ozone adding amount.
(2) Domestic sewage passes through the coarse grid and the lifting pump station and then enters the fine grid and the grit chamber, and the domestic sewage and the oxidized and decomposed industrial wastewater form mixed wastewater;
(3) The mixed wastewater enters an AAO pool, a carbon source is added into the AAO pool, the mixed wastewater enters an MBR pool after reaction, the biomass of a treatment system of the AAO pool is increased in the MBR pool, and the concentration of the mixed liquor is increased from MLSS =4000mg/l designed originally to MLSS =12000mg/l, so that the constructed AAO pool can meet the requirement of biodegradation; secondly, the nano ceramic ultrafiltration membrane is adopted, so that the treatment process and the civil construction investment are simplified, and the stable standard of the effluent is ensured; thirdly, the interception effect of the nano ceramic ultrafiltration membrane on macromolecular and difficultly degraded COD is fully exerted, the content of the COD of the effluent is reduced, and the standard of the COD and the chromaticity of the effluent is ensured;
liquid in the MBR tank flows back to the AAO tank, mixed wastewater after reaction in the MBR tank enters a disinfection tank, is disinfected by sodium hypochlorite, and is discharged after reaching the standard through a metering tank;
(4) The sludge in the primary sedimentation tank and the sludge in the MBR tank enter a sludge concentration tank for concentration, the concentrated sludge enters a sludge conditioning tank, and a conditioning agent is added into the sludge conditioning tank, wherein the sludge conditioning only needs to add a PAC agent, and does not need to add lime, ferric trichloride and PAM; firstly, the difficulty of outward transportation and disposal of the sludge is improved, and secondly, the total amount of the sludge is reduced; thirdly, the sludge treatment cost is reduced; fourthly, the possibility of recycling the sludge is improved. And (4) conditioning the sludge, then entering a sludge dewatering machine room, and transporting the dewatered sludge outside.
The invention has the beneficial effects that:
the scale of the industrial wastewater treatment and system based on multistage precipitation can reach 5 ten thousand meters 3 D, wherein the industrial wastewater is 3.2 ten thousand meters 3 D, domestic sewage 1.8 ten thousand meters 3 And d, the effluent quality reaches the first grade A standard of pollutant discharge Standard of municipal wastewater treatment plant (GB 18918-2002).
The invention can decompose more COD which is difficult to be biochemically generated into easily-biochemically generated COD, reduce the energy consumption and the operation cost of the whole sewage treatment plant, reduce the content of the COD of the effluent, and ensure that the COD and the chromaticity of the effluent reach the standard.
Drawings
FIG. 1: the invention relates to a process flow chart for treating mixed sewage.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
As described in the background, the present invention provides a multistage precipitation-based industrial wastewater treatment process, comprising the steps of:
(1) Industrial wastewater enters an anaerobic tank through a regulating tank, a medicament is added into the anaerobic tank, the industrial wastewater enters a primary sedimentation tank for sedimentation after reaction, and the sedimentated sludge flows back to the anaerobic tank, wherein the reflux ratio is 100%. The precipitated industrial wastewater enters an ozone contact tank, a carbon source is added into the ozone contact tank, and the industrial wastewater is subjected to oxidative decomposition;
(2) Domestic sewage passes through the coarse grid and the lifting pump station and then enters the fine grid and the grit chamber, and the domestic sewage and the oxidized and decomposed industrial wastewater form mixed wastewater;
(3) The mixed wastewater enters an AAO pool, a carbon source is added into the AAO pool, the mixed wastewater enters an MBR pool after reaction, liquid in the MBR pool flows back to the AAO pool, the reflux ratio is 300%, the mixed wastewater after reaction in the MBR pool enters a disinfection pool and is disinfected by sodium hypochlorite, and the mixed wastewater passes through a metering tank and is discharged after reaching the standard;
(4) And (3) the sludge in the primary sedimentation tank and the sludge in the MBR tank enter a sludge concentration tank for concentration, the concentrated sludge enters a sludge conditioning tank, a conditioning agent is added into the sludge conditioning tank, the conditioned sludge enters a sludge dewatering machine room, and the dewatered sludge is transported outside.
In order to make the technical solutions of the present application more clearly understood by those skilled in the art, the technical solutions of the present application will be described in detail below with reference to specific embodiments.
The test materials used in the examples of the present invention were all conventional in the art and commercially available.
Examples
The process flow of the industrial wastewater treatment based on the multistage precipitation is shown in figure 1, and the treated wastewater is divided into two types, specifically shown in table 1.
TABLE 1
(1) Industrial waste water enters an anaerobic tank through a regulating tank, polyacrylamide is added into the anaerobic tank, and the concentration of polyacrylamide is 5000m per anaerobic tank 3 1kg of polyacrylamide was added to the wastewater. The industrial wastewater enters a primary sedimentation tank for sedimentation after reaction, and the sedimentated sludge flows back to the anaerobic tank with the reflux ratio of 100 percent. The precipitated industrial wastewater enters an ozone contact tank, a carbon source is added into the ozone contact tank, and the industrial wastewater is subjected to oxidative decomposition;
(2) Domestic sewage passes through the coarse grid and the lifting pump station and then enters the fine grid and the grit chamber, and the domestic sewage and the oxidized and decomposed industrial wastewater form mixed wastewater;
(3) The mixed wastewater enters an AAO pool, glucose is added into the AAO pool, and 250kg of glucose is added into each ton of wastewater. And (3) after reaction, the wastewater enters an MBR tank, the liquid in the MBR tank flows back to the AAO tank, the reflux ratio is 300%, the mixed wastewater after the reaction in the MBR tank enters a disinfection tank, and is disinfected by sodium hypochlorite, wherein the addition amount of the sodium hypochlorite is 12 tons/day. The mixed wastewater passes through a metering tank and is discharged after reaching the standard; the effluent quality of the wastewater is shown in Table 3.
(4) The sludge in the primary sedimentation tank and the sludge in the MBR tank enter a sludge concentration tank for concentration, the concentrated sludge enters a sludge conditioning tank, and polyaluminium chloride is added into the sludge conditioning tank every 5000m 3 10kg of polyaluminium chloride was added to the waste water. And (4) conditioning the sludge, then sending the conditioned sludge into a sludge dewatering machine room, and transporting the dewatered sludge outside.
The effluent quality reaches the first grade A standard of pollutant discharge Standard of urban Sewage treatment plant (GB 18918-2002).
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (9)
1. The industrial wastewater treatment process based on multistage precipitation is characterized by comprising the following steps:
(1) Industrial wastewater enters an anaerobic tank through a regulating tank, a medicament is added into the anaerobic tank, the industrial wastewater enters a primary sedimentation tank for sedimentation after reaction, the precipitated sludge flows back to the anaerobic tank, the precipitated industrial wastewater enters an ozone contact tank, a carbon source is added into the ozone contact tank, and the industrial wastewater is subjected to oxidative decomposition;
(2) Domestic sewage passes through the coarse grid and the lifting pump station and then enters the fine grid and the grit chamber, and the domestic sewage and the oxidized and decomposed industrial wastewater form mixed wastewater;
(3) The mixed wastewater enters an AAO tank, a carbon source is added into the AAO tank, the mixed wastewater enters an MBR tank after reaction, liquid in the MBR tank flows back to the AAO tank, the mixed wastewater after reaction in the MBR tank enters a disinfection tank and is disinfected by sodium hypochlorite, and the mixed wastewater passes through a metering tank and is discharged after reaching the standard;
(4) And (3) the sludge in the primary sedimentation tank and the sludge in the MBR tank enter a sludge concentration tank for concentration, the concentrated sludge enters a sludge conditioning tank, a conditioning agent is added into the sludge conditioning tank, the conditioned sludge enters a sludge dewatering machine room, and the dewatered sludge is transported outside.
2. The industrial wastewater treatment process based on multistage precipitation according to claim 1, wherein in step (1), the added agent is Polyacrylamide (PAA) with a dosage of 5000m 3 1kg of polyacrylamide was added to the wastewater.
3. The industrial wastewater treatment process based on multistage precipitation according to claim 1, wherein in the step (1), the reflux ratio of the primary precipitation tank is 100%.
4. The industrial wastewater treatment process based on multistage precipitation according to claim 1, wherein the carbon source added in step (3) is glucose, and 250kg of glucose is added per ton of wastewater.
5. The industrial wastewater treatment process based on multistage precipitation according to claim 1, wherein the reflux ratio of the MBR tank in the step (3) is 300%.
6. The industrial wastewater treatment process based on multistage precipitation according to claim 1, wherein the amount of sodium hypochlorite added in step (3) is 11 to 12 tons/day.
7. The multistage precipitation-based industrial wastewater treatment process according to claim 1, wherein in the step (4), the conditioning agent is polyaluminum chloride (PAC) with the concentration of every 5000m 3 10kg of polyaluminium chloride was added to the waste water.
8. The industrial wastewater treatment system based on multistage sedimentation is characterized by comprising an adjusting tank, an anaerobic tank, a primary sedimentation tank, an ozone contact tank, an AAO tank, an MBR tank, a disinfection tank and a metering tank which are sequentially connected, wherein the AAO tank is further sequentially connected with a sand sedimentation tank and a lifting pump station, the primary sedimentation tank and the MBR tank are connected with a sludge concentration tank, and the sludge concentration tank is sequentially connected with a sludge conditioning tank and a sludge dewatering machine room.
9. The industrial wastewater treatment system based on multistage sedimentation according to claim 8, wherein the grit chamber is provided with a fine grid, and the lifting pump station is provided with a coarse grid.
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