Method for treating dimethyl phthalate in sewage by using algal-bacterial symbiotic sludge

Abstract

The invention provides a method for treating dimethyl phthalate in sewage by using algal-bacterial symbiotic sludge. The method comprises the following steps: carrying out biodegradation treatment on sewage by utilizing an algal-bacterial symbiotic sludge system; wherein the sewage comprises dimethyl phthalate. The bacteria-algae symbiotic sludge system provided by the invention can improve the removal rate of dimethyl phthalate and other pollutants in sewage.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a method for treating dimethyl phthalate in sewage by using bacteria-algae symbiotic sludge. Background Art

[0002] With the development of science and technology, pollutants in domestic sewage tend to be diversified. New pollutants, as chemical substances with environmental persistence, bioaccumulation and biotoxicity, have increasingly prominent impacts on the environment. Among them, dimethyl phthalate, as a common plasticizer, has the characteristics of low solubility and low volatility, and is widely used in plastic manufacturing and processing industries. As an endocrine disruptor among new pollutants, dimethyl phthalate will disrupt normal hormone responses and has the characteristics of "teratogenicity, carcinogenicity, and mutagenicity". Its hydrolysis half-life is more than 3 years. It is quite stable in the water environment and is listed as a priority pollutant by the US Environmental Protection Agency. Therefore, strict treatment and control of new pollutants in water bodies is imperative.

[0003] Microbial degradation is one of the most effective, green and cost-friendly methods for removing pollutants and is widely used in the sewage treatment industry. However, the target pollutants of the traditional activated sludge method and membrane biological treatment process implemented in sewage treatment plants are not new pollutants and cannot completely degrade these compounds. Therefore, it is urgent to seek an efficient and energy-saving biological treatment technology. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for treating dimethyl phthalate in sewage by using bacteria-algae symbiotic sludge.

[0005] In a first aspect, the present invention provides a method for treating dimethyl phthalate in sewage by using bacteria-algae symbiotic sludge, comprising: using a bacteria-algae symbiotic sludge system to perform biodegradation treatment on the sewage; wherein the sewage comprises dimethyl phthalate.

[0006] The algae-microbial symbiotic technology has the advantages of low energy demand, cost-effectiveness and potential resource recovery. Microalgae and bacteria form a symbiotic relationship in the algae-microbial symbiotic system, which significantly improves the removal efficiency of nitrogen and phosphorus in the system. At the same time, activated sludge and microalgae have good biodegradation ability for dimethyl phthalate. Microalgae absorb carbon dioxide and nutrients in water released by bacteria when treating organic matter, and then produce oxygen for further use by bacteria, thereby promoting the degradation of organic matter and helping to reduce aeration energy consumption in the system to meet green treatment standards.

[0007] In some embodiments, the concentration of dimethyl phthalate (DMP) in the sewage is 1-30 mg / L; for example, 1 mg / L, 3 mg / L, 5 mg / L, 8 mg / L, 10 mg / L, 13 mg / L, 20 mg / L, 25 mg / L, 30 mg / L or any value therebetween.

[0008] In some embodiments, the concentration of dimethyl phthalate (DMP) in the wastewater is 5-30 mg / L.

[0009] In some embodiments, the concentration of dimethyl phthalate (DMP) in the wastewater is 5-25 mg / L.

[0010] In some embodiments, the concentration of dimethyl phthalate (DMP) in the wastewater is 10-25 mg / L.

[0011] In some embodiments, the sewage also includes ammonia nitrogen, COD, phosphorus and other pollutants.

[0012] In some embodiments, other contaminants include magnesium ions, calcium ions, and potassium ions.

[0013] In some embodiments, the method comprises:

[0014] (1) Construct a bacteria-algae symbiotic sludge system;

[0015] (2) The bacteria-algae symbiotic sludge system is inoculated into a photobioreactor, and then sewage is introduced for biodegradation treatment.

[0016] In some embodiments, the bacteria-algae symbiotic sludge system comprises microalgae and domesticated activated sludge.

[0017] In some embodiments, constructing a bacteria-algae symbiotic sludge system comprises the following steps: expanding the culture of microalgae and then inoculating them into the suspended solids of the acclimated activated sludge mixed liquor.

[0018] The present invention uses microalgae and activated sludge to form a bacteria-algae symbiotic sludge system. Through the adsorption of the bacteria-algae symbiotic sludge system and the degradation of microorganisms, the removal rate of other pollutants (such as ammonia nitrogen, COD, phosphorus, magnesium ions, calcium ions and potassium ions, etc.) and dimethyl phthalate in sewage is greatly improved, and it also has the advantages of strong impact resistance, good sedimentation performance and low carbon energy saving. The bacteria-algae symbiotic sludge has good tolerance and removal rate for pollutants of different concentrations, wherein the microalgae can absorb the carbon dioxide released during the degradation of pollutants and produce oxygen at the same time, which helps to reduce the aeration energy consumption in the system, and provides a high-efficiency, energy-saving and environmentally sustainable wastewater treatment alternative for sewage treatment plants.

[0019] The present invention utilizes microalgae and activated sludge to form a bacteria-algae symbiotic sludge system. First, the microalgae absorbs carbon dioxide and nutrients in the water released by bacteria when treating organic matter, and then produces oxygen for further use by bacteria, thereby promoting the degradation of organic matter and reducing aeration energy consumption in the system to meet the standards of green treatment. Secondly, microalgae and bacteria form a stable symbiotic relationship in the bacteria-algae symbiotic system, which significantly improves the removal efficiency of pollutants such as nitrogen, phosphorus, and dimethyl phthalate in the system. Finally, the bacteria-algae symbiotic system allows microalgae to transform from a suspended state to an attached state, solving the problems of difficulty in collecting microalgae and high levels of suspended matter in the effluent, and providing the possibility for microalgae to treat wastewater and achieve energy recovery.

[0020] In some embodiments, the concentration of mixed liquor suspended solids (MLSS) of the domesticated activated sludge is 4000±150 mg / L, for example, 3850 mg / L, 3900 mg / L, 3950 mg / L, 4000 mg / L, 4050 mg / L, 4100 mg / L, 4150 mg / L or any value therebetween.

[0021] In some embodiments, the weight ratio of the mixed liquor suspended solids (MLSS) of the microalgae and the domesticated activated sludge is 1:(4-8), for example, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8 or any value therebetween.

[0022] In some embodiments, the domesticated activated sludge is obtained by the following steps: domesticating and culturing the activated sludge with artificial synthetic sewage.

[0023] In some embodiments, the activated sludge includes activated sludge in an SBR reactor of a municipal sewage treatment plant.

[0024] In some embodiments, the initial concentration of activated sludge in the SBR reactor is 4000±150 mg / L, for example, 3850 mg / L, 3900 mg / L, 3950 mg / L, 4000 mg / L, 4050 mg / L, 4100 mg / L, 4150 mg / L or any value therebetween.

[0025] In some embodiments, the artificial synthetic domestic sewage comprises COD, dimethyl phthalate, magnesium ions, calcium ions, potassium ions, ammonia nitrogen and TP.

[0026] In some embodiments, the artificial synthetic sewage comprises: COD 200-400 mg / L, dimethyl phthalate 1-20 mg / L, magnesium ion 10-30 mg / L, calcium ion 10-30 mg / L, potassium ion 10-30 mg / L, ammonia nitrogen 20-40 mg / L and TP5-20 mg / L.

[0027] In some embodiments, the cyclic operation process of the acclimation culture includes four stages: air intake, aeration, sedimentation, and drainage.

[0028] In some embodiments, the cyclic operation process of the acclimation culture includes: anoxic / anaerobic water intake for 50-70 minutes, aeration for 70-120 minutes, sedimentation for 10-40 minutes, and drainage for 5-10 minutes.

[0029] During the operation, the floc sludge in the reactor that cannot adapt to the water quality and has poor sedimentation performance is continuously discharged, and the sludge settling performance gradually improves.

[0030] In some embodiments, the acclimation culture adopts a pattern of 3 hours as one cycle and 8 cycles per day.

[0031] In some embodiments, the microalgae includes Chlorella vulgaris (FACHB-31).

[0032] In some embodiments, the culture medium for expansion includes BG11 medium.

[0033] In some embodiments, the concentration of the microalgae is (1-5)×10 7 / mL, for example, 1×10 7 / mL, 1.5×10 7 / mL, 2×10 7 / mL, 2.5×10 7 / mL, 3×10 7 / mL, 3.5×10 7 / mL, 4×10 7 / mL, 4.5×10 7 / mL, 5×10 7 / mL or any value therebetween.

[0034] In some embodiments, the photobioreactor includes a SBR reactor and a light source wrapped around the SBR reactor.

[0035] In some embodiments, the light source comprises an LED lamp.

[0036] In some embodiments, the light intensity of the light source is 5000-7000 lux; for example, 5500 lux, 6000 lux, 6500 lux, 7000 lux or any value therebetween.

[0037] In some embodiments, the SBR reactor is operated in an aerobic and / or anoxic mode.

[0038] In some embodiments, the operation cycle of the SBR reactor includes: water intake for 50-70 min, preferably 60 min, aeration for 80-115 min, preferably 90-115 min, sedimentation for 15-30 min, preferably 25-30 min, drainage for 1-10 min, preferably 5 min, using 2-5 h as a cycle, preferably 3 h, and a mode of 8 cycles a day. The aeration process controls the gas flow rate to 0.5-2 L / min, and uses 0.5-2 mol / L hydrochloric acid to adjust the inlet pH to 7.0, preferably using 0.5 mol / L hydrochloric acid, and the heating belt and thermostat control the water temperature to 25±2°C.

[0039] In some embodiments, the sewage treatment method comprises:

[0040] S1, domestication of activated sludge: take the activated sludge from the SBR pool of the urban sewage treatment plant, and cultivate it after artificial synthetic domestic sewage, and then inoculate it for use;

[0041] S2, Construction of bacteria-algae symbiotic sludge system: The mixed liquor suspended solids (MLSS) of activated sludge was adjusted to 4000±150mg / L; Chlorella was expanded in advance to a concentration of 3×10 7 Pieces / mL;

[0042] S3, the initial inoculum is a mixture of microalgae and sludge in a weight ratio of 1:6, and an external light source LED lamp is set on the basis, which is wound around the reactor to control the light intensity to 6000 lux, and the aerobic / anoxic mode is adopted for operation. The cycle is as follows: water inlet 60min, aeration 90min, sedimentation 25min, drainage 5min, 3h as a cycle, 8 cycles a day, the gas flow rate of the aeration process is controlled to 1L / min, 1mol / L hydrochloric acid is used to adjust the inlet pH to 7.0, and the heating belt and thermostat control the water temperature to 25±2℃;

[0043] S4, introduce simulated domestic wastewater from a sewage treatment plant containing conventional pollutants and dimethyl phthalate for biodegradation treatment.

[0044] In some embodiments, a peristaltic pump is used in step S3 to ensure that the static water inflow to the reactor is uniformly flowed.

[0045] In some embodiments, in step S3, an aeration pump and an aeration head are used to supply gas, and the aeration pump and a rotor flowmeter control the gas flow.

[0046] In some embodiments, the lighting, water inlet pump, drain valve, and aeration pump of each reactor system in step S3 are all connected and controlled by an intelligent timing plug strip.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] (1) The present invention can improve the efficiency of treating new pollutant dimethyl phthalate in sewage treatment plants.

[0049] (2) In the bacteria-algae symbiotic sludge system of the present invention, the microalgae absorb the carbon dioxide and nutrients in the water released when the bacteria treat the organic matter, and then produce oxygen for the bacteria to further use, thereby promoting the degradation of organic matter and improving the removal rate of conventional pollutants.

[0050] (3) The bacteria-algae symbiotic system of the present invention enables the microalgae to transform from a suspended state to an attached state, thereby solving the problem of high content of suspended solids in the effluent and improving the sedimentation performance of the sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 a is a schematic diagram of the SBR reactor used in the present invention;

[0052] Figure 1 b is a physical picture of the SBR reactor used in the invention;

[0053] Figure 2 It is the SVI variation diagram during the operation of the reactor;

[0054] Figure 3 This is the chlorophyll change diagram during the operation of the reactor;

[0055] Figure 4 This is the ammonia nitrogen removal law diagram during the operation of the reactor;

[0056] Figure 5 is the orthophosphate removal law diagram during the operation of the reactor;

[0057] Figure 6 This is the COD removal law diagram during the operation of the reactor;

[0058] Figure 7 (a) is a diagram showing the removal of DMP in a typical cycle during the operation of a flocculent activated sludge reactor;

[0059] Figure 7 (b) is a diagram showing the DMP removal pattern during a typical period of operation of the bacteria-algae symbiotic sludge reactor. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention.

[0061] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0062] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the reagent amounts, unless otherwise specified, are the reagent amounts used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0063] The composition of the BG11 culture medium used in the present invention is as follows: NaNO3 1500mg / L, K2HPO4 40mg / L, MgSO4 36.6mg / L, CaCl2 27.2mg / L, Citric acid 6mg / L, Ammonium ferric citrate 6mg / L, EDTANa2 1mg / L, Na2CO3 20mg / L, H3BO3 2.86mg / L, MnCl2·4H2O1.81mg / L, ZnSO4 0.22mg / L, Na2MoO4·2H2O 0.39mg / L, CuSO4·5H2O 0.08mg / L, CoCl2·6H2O 0.0409mg / L.

[0064] COD in the present invention refers to chemical oxygen demand, which refers to the amount of oxygen consumed when strong oxidants are used to chemically oxidize organic matter in the wastewater being tested, and the unit is mg / L. The larger the COD value, the higher the degree of water pollution.

[0065] TP in the present invention refers to total phosphorus, which is the result of determination after various forms of phosphorus in a water sample are converted into orthophosphate after digestion, and is measured in milligrams of phosphorus per liter of water sample.

[0066] The SVI in the present invention represents the sludge volume index, which is an indicator for measuring the settling performance of activated sludge.

[0067] SVI5 refers to the volume (in mL) occupied by 1g of dry sludge after 5 minutes of sedimentation of the mixed liquor in the aeration tank, and the unit is mL / g. That is, SVI = sludge volume (mL) after 5 minutes of sedimentation of the mixed liquor / sludge dry weight (g), that is, SVI = (volume of activated sludge formed by 5 minutes of static sedimentation of 1L mixed liquor (mL)) / (dry weight of suspended solids in 1L mixed liquor). SVI 10 , SVI 30 Calculated in the same way, the SVI value can better reflect the looseness and coagulation and sedimentation performance of the activated sludge.

[0068] Chl a in the present invention refers to chlorophyll a.

[0069] Chl b in the present invention refers to chlorophyll b.

[0070] In order to facilitate the monitoring of pollutant degradation effects, the experiment used artificial synthetic simulated domestic sewage from a sewage treatment plant, including 300 mg / L COD, 1-20 mg / L dimethyl phthalate, 20 mg / L magnesium ions, 20 mg / L calcium ions, 20 mg / L potassium ions, 30 mg / L ammonia nitrogen, and 10 mg / L TP.

[0071] The activated sludge was domesticated by using the activated sludge from the SBR tank of the urban sewage treatment plant. After being domesticated and cultured with artificial domestic sewage, it was inoculated for use. The construction of the bacteria-algae symbiotic sludge system was as follows: the mixed liquor suspended solids (MLSS) of the activated sludge was adjusted to 4000±150mg / L; the Chlorella was expanded in advance to a concentration of 3×10 7 The initial inoculum was a mixture of microalgae and sludge in a weight ratio of 1:6 and was inoculated into an SBR reactor with a diameter of 10 cm, a height of 50 cm, and an effective volume of 3 L (such as Figure 1 a), an external light source LED lamp (as shown in Figure 1 b), wound around the reactor, controlling the light intensity to 6000 lux, and operating in aerobic / anoxic mode, with the following cycles: 60 min of water inlet, 90 min of aeration, 25 min of sedimentation, 5 min of drainage, 3 h as one cycle, 8 cycles a day, the gas flow rate during aeration controlled at 1 L / min, 1 mol / L hydrochloric acid was used to adjust the inlet pH to 7.0, and the heating tape and thermostat controlled the water temperature to 25±2°C; simulated domestic wastewater from a sewage treatment plant containing conventional pollutants and dimethyl phthalate (DMP) was introduced for biodegradation treatment.

[0072] In the construction of the bacteria-algae symbiotic sludge system, the inoculum is Chlorella vulgaris FACHB-31, which is inoculated and expanded using BG11 culture medium. A peristaltic pump is used in the SBR reactor to ensure that the reactor has a uniform static water inlet flow rate. An aeration pump and an aeration head are used to supply air. The aeration pump and rotor flowmeter control the gas flow. The system lighting, water inlet pump, drain valve, and aeration pump are all connected and controlled by intelligent timing plug-in strips.

[0073] After the system is running stably, monitor the degradation performance of conventional pollutants, degradation performance of new pollutants, microbial community structure, sludge physical and chemical properties, etc.

[0074] Using this method, the physicochemical properties of sludge and the degradation performance of pollutants such as Figure 2 As shown in Figure 2, the settling performance of the sludge was significantly improved, and the SVI 30 / SVI5 is higher than 0.9, indicating that the bacterial-algal symbiotic sludge has excellent settling performance and good mud-water separation effect; as the DMP concentration gradually increases from 1 mg / L, the SVI of traditional flocculent activated sludge and bacterial-algal symbiotic sludge 30 and SVI 10 , SVI5 values ​​decreased slowly and the trend was similar, SVI 30 / SVI5 rises slowly. The final flocculent activated sludge SVI 30 Maintained at around 62mL / g, SVI 30 / SVI5 ratio is close to 0.9; SVI of algae symbiotic sludge 30 Slowly decreased and finally stabilized at 51mL / g, SVI 30 / SVI5 ratio is higher than 0.9. The results show that compared with traditional flocculent sludge, algae symbiotic sludge has better sedimentation performance, better mud-water separation effect, and slightly higher biomass than ordinary activated sludge. As the DMP concentration gradually increased from 1, 5, 10, and 20 mg / L, the chlorophyll content in the system was determined by spectrophotometry. The chlorophyll a, b, and total chlorophyll in the algae symbiotic sludge can reach 1.68, 0.39, and 4.31 (mg / g SS), respectively. Figure 3 As shown in the figure, it shows that microalgae can grow in domestic sewage with a dimethyl phthalate concentration of 1 to 20 mg / L. The removal rates of ammonia nitrogen, orthophosphate, and COD by the bacterial-algal symbiotic system are higher than those of traditional flocculent sludge. Figure 4-6As shown. During the long-term, high-concentration DMP acclimation process, the microalgae gradually adapted to growth, and the diverse microbial communities were conducive to the advantages of the algae-bacteria symbiotic sludge system in treating pollutants, showing faster DMP removal efficiency. In the aerobic stage, the flocculent activated sludge can completely remove 1, 5, 10, and 20 mg / L of DMP within 15, 40, 50, and 60 minutes after aeration, respectively, and the algae-bacteria symbiotic sludge can completely remove it within 40, 35, 40, and 50 minutes after aeration, respectively. During the entire reaction stage, compared with traditional flocculent sludge (such as Figure 7 (a) shows that the bacterial-algal symbiotic sludge showed a more stable removal rate for high concentration of dimethyl phthalate, such as Figure 7 (b) as shown.

[0075] It can be seen that the microalgae and activated sludge of the present invention constitute a bacteria-algae symbiotic sludge system, and organic matter is removed through the adsorption of the bacteria-algae symbiotic sludge and the degradation of microorganisms.

[0076] Therefore, the present invention has the following effects:

[0077] (1) In the process of treating pollutants, due to the symbiotic effect of bacteria and algae, the bacteria-algae symbiotic sludge system has the ability to fix carbon, nitrogen and phosphorus more efficiently, and at the same time has a good removal ability for the new pollutant dimethyl phthalate.

[0078] (2) In the bacteria-algae symbiotic sludge system, the microalgae absorb the carbon dioxide and nutrients in the water released by the bacteria when they treat organic matter, and then produce oxygen for the bacteria to further use, thereby promoting the degradation of organic matter, reducing carbon dioxide emissions and aeration intensity in the system, meeting the standards of green treatment, and promoting environmental sustainable development, while reducing the energy consumption costs of sewage treatment plants.

[0079] (3) The bacteria-algae symbiotic system enables the microalgae to transform from a suspended state to an attached state, thus solving the problem of high suspended solids in the effluent and improving the sedimentation performance of the sludge.

[0080] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for treating dimethyl phthalate in sewage by using bacteria-algae symbiotic sludge, comprising: The bacterial-algal symbiotic sludge system is used to biodegrade sewage, wherein the sewage includes dimethyl phthalate.

2. The method according to claim 1, characterized in that The concentration of dimethyl phthalate in the sewage is 1-30 mg / L, preferably 5-30 mg / L, for example 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L; and / or The sewage also includes ammonia nitrogen, COD and phosphorus.

3. The method according to claim 1 or 2, characterized in that: The method comprises: (1) Construct a bacteria-algae symbiotic sludge system; (2) The bacteria-algae symbiotic sludge system is inoculated into a photobioreactor, and then sewage is introduced for biodegradation treatment.

4. The method according to any one of claims 1 to 3, characterized in that The bacteria-algae symbiotic sludge system comprises microalgae and domesticated activated sludge; Preferably, constructing the bacteria-algae symbiotic sludge system comprises the following steps: expanding the culture of microalgae and then inoculating them into the suspended solids of the mixed liquid of the domesticated activated sludge.

5. The method according to claim 4, characterized in that The concentration of suspended solids in the mixed liquor of the activated sludge after acclimation is 4000±150 mg / L; and / or The weight ratio of suspended solids in the mixed liquid of the microalgae and the domesticated activated sludge is 1:(4-8).

6. The method according to claim 4 or 5, characterized in that: The domesticated activated sludge is obtained by the following steps: The activated sludge is domesticated and cultivated with artificial synthetic sewage.

7. The method according to any one of claims 4 to 6, characterized in that: The activated sludge includes activated sludge in the SBR reactor of the municipal sewage treatment plant; Preferably, the initial concentration of activated sludge in the SBR reactor is 4000±150 mg / L; and / or The artificial synthetic domestic sewage includes COD, dimethyl phthalate, magnesium ions, calcium ions, potassium ions, ammonia nitrogen and TP.

8. The method according to claim 7, characterized in that The artificial synthetic sewage comprises: COD 200-400 mg / L, dimethyl phthalate 1-20 mg / L, magnesium ion 10-30 mg / L, calcium ion 10-30 mg / L, potassium ion 10-30 mg / L, ammonia nitrogen 20-40 mg / L and TP 5-20 mg / L.

9. The method according to any one of claims 4 to 8, characterized in that: The microalgae include Chlorella, preferably, the microalgae include FACHB-31; and / or The culture medium for the expanded culture includes BG11 culture medium, and / or The concentration of the microalgae is (1-5)×10 7 Pieces / mL.

10. The method according to any one of claims 3 to 9, characterized in that: The photobioreactor comprises an SBR reactor and a light source wound around the SBR reactor; preferably, the light source comprises an LED lamp; and / or The light intensity of the light source is 5000-7000 lux; and / or The SBR reactor is operated in aerobic and / or anoxic mode, and / or The operation cycle of the SBR reactor includes: water intake for 50-70 minutes, aeration for 80-115 minutes, sedimentation for 15-30 minutes, and drainage for 1-10 minutes. The mode is 2-5 hours as one cycle and 8 cycles a day. The gas flow rate during the aeration process is controlled to be 0.5-2L / min, and the pH of the inlet water is adjusted to 7.0 using 0.5-2mol / L hydrochloric acid. The heating belt and thermostat control the water temperature to 25±2°C.

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