A method and system for treating effluent from a wastewater treatment plant

Abstract

This invention discloses a method and system for treating wastewater effluent from a wastewater treatment plant. The method includes the following steps: acquiring parameter data of the effluent, including total phosphorus, suspended solids concentration, total nitrogen, and chemical oxygen demand (COD); selecting a corresponding effluent treatment method based on the parameter data, wherein the treatment method includes sedimentation, denitrification, and / or COD removal; and discharging the treated effluent into a clear water tank. This invention, through data analysis, customized treatment strategies, and discharge mechanisms, can flexibly adjust the treatment method according to the effluent conditions, achieving efficient pollution removal and cost savings.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to a method and system for treating wastewater. Background Technology

[0002] With rapid industrialization and urbanization, water pollution has become increasingly serious, making wastewater treatment plants particularly important for water pollution control. Adding advanced treatment processes after biological secondary treatment can effectively improve the effluent quality of wastewater treatment plants. Common advanced wastewater treatment technologies include physicochemical methods, biological treatment methods, and advanced oxidation processes. However, each advanced treatment technology has its specific application scope and limitations, and a single technology is often insufficient to fully meet high emission standards. Summary of the Invention

[0003] The technical problem this invention aims to solve is that existing wastewater treatment technologies are relatively simple and cannot fully meet high-standard discharge requirements.

[0004] To address the aforementioned technical problems, this invention provides a method for treating wastewater effluent from a wastewater treatment plant, comprising the following steps:

[0005] Obtain parameter data for the effluent, including the concentrations of total phosphorus, suspended solids, total nitrogen, and chemical oxygen demand.

[0006] The corresponding wastewater treatment method is selected based on the parameter data. The wastewater treatment method includes sedimentation treatment of the wastewater, denitrification treatment of the wastewater, and / or removal of chemical oxygen demand treatment of the wastewater.

[0007] The treated wastewater is discharged into the clear water tank.

[0008] Furthermore, selecting the corresponding wastewater treatment method based on the parameter data includes:

[0009] When the total phosphorus and suspended solids concentrations in the effluent do not meet the discharge requirements, the effluent is subjected to sedimentation treatment.

[0010] When the total phosphorus, suspended solids and total nitrogen concentrations of the effluent do not meet the discharge requirements, the effluent shall be subjected to sedimentation treatment and denitrification treatment.

[0011] When the chemical oxygen demand (COD) content of the effluent does not meet the discharge requirements, the effluent is treated to remove COD.

[0012] When the total phosphorus, suspended solids concentration, total nitrogen, and chemical oxygen demand (COD) content of the effluent do not meet the discharge requirements, the effluent is subjected to sedimentation treatment, nitrogen removal treatment, and COD removal treatment.

[0013] Further, the precipitation treatment includes:

[0014] The effluent enters the mixing reaction zone of the sedimentation tank and reacts with the coagulant to aggregate the insoluble particles in the effluent into flocs.

[0015] Subsequently, the tailwater carrying flocs and alum flocs flows through the flocculation reaction zone and reacts with the flocculant, causing the flocs and alum flocs to form flocs;

[0016] The wastewater carrying flocs enters the sedimentation zone for sedimentation, so that a supernatant is formed in the upper part of the sedimentation zone.

[0017] Furthermore, the coagulant is a polyferric chloride or polyaluminum chloride solution, and the ratio of the coagulant to the total phosphorus in the effluent is 6-15 ((mg / L) / (mg / L)).

[0018] Furthermore, the flocculant is a polyacrylamide solution, and the ratio of the flocculant to the suspended solids in the effluent is 0.01-0.06 ((mg / L) / (mg / L)).

[0019] Furthermore, the tailwater carrying flocs enters a sedimentation zone for sedimentation to form a supernatant, comprising:

[0020] The effluent carrying the flocs enters the sedimentation zone for sedimentation, where sludge accumulates at the bottom and clear water forms a supernatant on the upper layer of the sedimentation zone.

[0021] A portion of the sludge is returned to the flocculation reaction zone for treatment, with a sludge return ratio of 3%-6%.

[0022] Further, the denitrification treatment includes:

[0023] The effluent flows into a denitrification filter, where a carbon source is added to remove total nitrogen from the effluent.

[0024] Furthermore, the chemical oxygen demand (COD) removal treatment includes:

[0025] The effluent flows to an ozone oxidation tank to remove COD, and the ratio of ozone dosage to COD in the ozone oxidation tank is 0.1-0.4.

[0026] The water flowing out of the ozone oxidation tank flows to the aerated biological filter for further COD removal. The aeration intensity of the aerated biological filter is 3-5 air-to-water ratio.

[0027] The present invention also provides a tailwater treatment system, which applies the tailwater treatment method described above to treat tailwater. The tailwater treatment system includes: a sewage tank, a sedimentation tank, a denitrification filter, an ozone oxidation tank, an aerated biological filter, a clear water tank, and multiple valves.

[0028] The wastewater tank is connected to the sedimentation tank, denitrification filter, ozone oxidation tank, and clear water tank respectively, and corresponding valves are installed on the connecting pipes of the wastewater tank to the sedimentation tank, denitrification filter, ozone oxidation tank, and clear water tank respectively; the sedimentation tank, denitrification filter, ozone oxidation tank, aerated biological filter, and clear water tank are connected in sequence, and corresponding valves are installed between the sedimentation tank and the denitrification filter, between the denitrification filter and the ozone oxidation tank, between the ozone oxidation tank and the aerated biological filter, and between the aerated biological filter and the clear water tank.

[0029] Furthermore, the sedimentation tank includes a coagulation reaction zone, a flocculation reaction zone, and a sedimentation zone connected in sequence. The wastewater tank is connected to the coagulation reaction zone, and the sedimentation zone is connected to the denitrification filter and the clear water tank, respectively. The sedimentation zone is provided with multiple inclined tubes, which are spaced apart in the horizontal direction and extend along their length and are inclined to one side. The diameter of the inclined tubes is 50-100mm, and the inclination angle of the inclined tubes is 55-70°.

[0030] Compared with the prior art, the wastewater treatment method and system of this invention have the following advantages:

[0031] This invention detects pollutant indicators in the effluent to reflect the degree of pollution, providing a basis for selecting appropriate treatment methods. Subsequently, based on the types and concentrations of the main pollutants in the effluent, the most suitable combination of treatment technologies is selected to achieve efficient purification. Finally, the treated effluent is introduced into a clear water tank. This invention, through data analysis, customized treatment strategies, and discharge mechanisms, can flexibly adjust the treatment method according to the effluent conditions, achieving efficient pollution removal and cost savings. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of the wastewater treatment method for wastewater treatment provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the tailwater treatment system provided in an embodiment of the present invention;

[0034] In the diagram, 1 is the wastewater tank; 2 is the sedimentation tank; 201 is the coagulation reaction zone; 202 is the flocculation reaction zone; 203 is the sedimentation zone; 204 is the inclined tube; 3 is the denitrification filter; 4 is the ozone oxidation tank; 401 is the ozone generator; 5 is the aerated biological filter; 501 is the aeration device; 502 is the packing material; 6 is the clear water tank; 7 is the first valve; 8 is the second valve; 9 is the third valve; 10 is the fourth valve; 11 is the fifth valve; 12 is the sixth valve; 13 is the seventh valve; 14 is the eighth valve; 15 is the ninth valve; 16 is the tenth valve; 17 is the eleventh valve; 18 is the twelfth valve; 19 is the thirteenth valve; 20 is the fourteenth valve; 21 is the fifteenth valve; 22 is the first pipe; 23 is the second pipe; 24 is the third pipe; 25 is the fourth pipe; 26 is the fifth pipe; 27 is the sixth pipe; 28 is the seventh pipe; and 29 is the eighth pipe. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0036] like Figure 1 and Figure 2 As shown, the present invention provides a wastewater treatment method, comprising the following steps:

[0037] S110. Obtain parameter data for the effluent, including total phosphorus (TP), suspended solids (SS), total nitrogen (TN), and chemical oxygen demand (COD).

[0038] This step involves detecting pollutant indicators in the effluent, including total phosphorus (TP), suspended solids (SS), total nitrogen (TN), and chemical oxygen demand (COD), to reflect the degree of pollution in the effluent and provide a basis for selecting appropriate treatment methods.

[0039] S120. Select the corresponding wastewater treatment method according to the parameter data. The wastewater treatment method includes sedimentation treatment, denitrification treatment and / or chemical oxygen demand removal treatment.

[0040] This step selects the most suitable combination of treatment technologies, such as sedimentation, denitrification, and / or chemical oxygen demand (COD) removal, based on the type and concentration of the main pollutants in the effluent, to achieve a highly efficient purification effect.

[0041] S130. Discharge the treated effluent into the clear water tank 6.

[0042] This step, by introducing the treated wastewater into the clear water tank 6, not only achieves the recycling of water resources and reduces the demand for fresh water, but also avoids secondary pollution to the environment caused by the direct discharge of untreated wastewater.

[0043] In summary, the above-mentioned wastewater treatment methods, through data analysis, customized treatment strategies, and discharge mechanisms, can flexibly adjust the treatment mode according to the effluent conditions, achieving efficient pollution removal and cost savings.

[0044] Furthermore, selecting the appropriate wastewater treatment method based on parameter data includes:

[0045] S121. When the total phosphorus and suspended solids concentrations in the effluent do not meet the discharge requirements, the effluent shall be treated by sedimentation.

[0046] In this step, when the total phosphorus (TP) and suspended solids (SS) concentrations in the effluent exceed the permissible discharge limits, it indicates that the effluent contains excessive phosphorus and suspended particulate matter. These substances may cause eutrophication of the aquatic ecosystem or reduce water transparency, affecting water quality. In this case, sedimentation treatment is used to cause these suspended solids to settle to the bottom, thereby purifying the water and reducing the SS and TP concentrations in the effluent to meet discharge standards, preventing additional burden on the environment.

[0047] S122. When the total phosphorus, suspended solids and total nitrogen concentrations of the effluent do not meet the discharge requirements, the effluent shall be subjected to sedimentation treatment and denitrification treatment.

[0048] Understandably, high concentrations of total nitrogen (TN) can also lead to eutrophication, promote excessive algal growth, and disrupt the aquatic ecological balance. In such cases, biological denitrification is employed, using microorganisms to convert ammonia nitrogen in the effluent into harmless nitrogen gas, which is then released into the atmosphere. This embodiment combines sedimentation and denitrification treatments to effectively remove suspended solids and nitrogen from the effluent, ensuring that the effluent meets stringent discharge standards and protecting the ecological health of the aquatic body.

[0049] S123. When the chemical oxygen demand (COD) content of the effluent does not meet the discharge requirements, the effluent shall be treated to remove COD.

[0050] Understandably, some effluent may contain large molecular organic matter, which is not easily decomposed by conventional biological treatment processes. Its presence hinders the self-purification capacity of water bodies and has long-term impacts on the ecological environment. For such effluent, treatment methods to remove large molecular organic matter that is difficult to biodegrade are necessary to eliminate these pollutants, ensure the safety and ecological compatibility of the effluent, and reduce potential harm to the natural environment.

[0051] S124. When the total phosphorus, suspended solids concentration, total nitrogen and chemical oxygen demand (COD) content of the effluent do not meet the discharge requirements, the effluent shall be treated by sedimentation, denitrification and COD removal.

[0052] Understandably, the simultaneous presence of excessive levels of TP, SS, TN, and COD in effluent indicates a high degree of pollution, necessitating comprehensive treatment. In this case, a complete advanced treatment system is formed by combining sedimentation, denitrification, and COD removal. This multi-step, comprehensive approach effectively addresses various pollutants, ensuring effluent meets discharge standards, achieving sustainable water resource management and utilization, and maintaining the balance and health of the ecosystem.

[0053] This embodiment can select the appropriate effluent treatment method according to the type and concentration of different pollutants, which can not only ensure the quality of effluent, but also take precise measures for specific problems, improve treatment efficiency, and reduce resource waste.

[0054] It should be noted that steps S121, S122, S123, and S124 in this embodiment are not sequential and are parallel implementation methods.

[0055] Furthermore, the sedimentation treatment includes: the effluent enters the mixing reaction zone of sedimentation tank 2 and reacts with a coagulant to aggregate insoluble particles in the effluent into flocs;

[0056] In this step, the effluent is first guided to the mixing reaction zone of sedimentation tank 2. Coagulant is added to the wastewater to cause the originally dispersed small particles to aggregate together through charge neutralization and bridging, forming larger flocs, i.e. flocs, which increases the settling speed of the particles and accelerates the purification process.

[0057] Subsequently, the tailwater carrying flocs and alum flocs flows through the flocculation reaction zone 202 and reacts with the flocculant, causing the flocs and alum flocs to form flocs;

[0058] In this step, the coagulated wastewater then flows into the flocculation reaction zone 202. At this stage, flocculants are added to promote further bonding between the flocs, forming larger flocs, further increasing the volume of the particles and improving their settling performance. Larger flocs are not only easier to separate from the water, but also able to capture more fine suspended solids, thus significantly improving water quality.

[0059] The tailwater carrying flocs enters the sedimentation zone 203 for sedimentation, so that a supernatant is formed in the upper part of the sedimentation zone 203.

[0060] In this step, the effluent carrying flocs finally enters the sedimentation zone 203. Due to gravity, the flocs quickly settle to the bottom of the tank, while the clear water remains on top, forming the supernatant. That is, through sedimentation, most of the suspended solids and colloidal substances are removed, greatly improving the transparency of the effluent.

[0061] This embodiment, from coagulation and flocculation to inclined plate sedimentation, together constitutes a highly efficient solid particle removal system. It can not only significantly reduce the content of suspended solids and colloidal substances in the effluent, but also remove some organic pollutants, improve water quality, and bring it closer to the discharge standards or reuse requirements.

[0062] Furthermore, the coagulant is a polyferric chloride or polyaluminum chloride solution (PAC, Polyaluminum Chloride), and the ratio of the coagulant to the total phosphorus in the effluent is 6-15 ((mg / L) / (mg / L)).

[0063] In this embodiment, polyaluminum chloride solution is used as an example of coagulant. Therefore, the total phosphorus ratio of the coagulant to the effluent is PAC / TP. When the coagulant dosage is insufficient (i.e., PAC / TP < 6), the TP in the wastewater may not settle completely, resulting in the effluent TP not meeting the standard. When the coagulant dosage is excessive (i.e., PAC / TP > 15), the excessive coagulant will reverse the properties of the suspended particles in the wastewater, and the particles will revert from a "destabilized" state to a "stable" state, resulting in a poorer subsequent coagulation effect. In addition, the use of excessive agents will also increase the treatment cost.

[0064] Furthermore, the flocculant is a polyacrylamide solution (PAM), and the ratio of the flocculant to the suspended solids in the effluent is 0.01-0.06 ((mg / L) / (mg / L)).

[0065] In this embodiment, polyacrylamide solution is used as an example of flocculant. Therefore, the ratio of flocculant to suspended solids in the effluent is PAM / SS. The flocculant has a direct impact on the removal of SS in the effluent. When the flocculant dosage is insufficient (i.e., PAM / SS < 0.01), the fine flocs formed in the coagulation stage cannot form larger flocs, resulting in poor settling performance and substandard SS in the effluent. When the flocculant dosage is excessive (i.e., PAM / SS > 0.06), the excessive flocculant will cause the formed flocs to be too large or too dense, which can easily lead to scaling and blockage of the inclined tube 204 pipe or equipment during subsequent sedimentation, thus reducing sedimentation efficiency. In addition, excessive use of reagents will also increase treatment costs.

[0066] Furthermore, the effluent carrying flocs enters sedimentation zone 203 for sedimentation to form a supernatant, including:

[0067] The effluent carrying flocs enters the sedimentation zone 203 for sedimentation. Sludge accumulates at the bottom of the sedimentation zone 203, while clear water forms supernatant on the upper layer of the sedimentation zone 203.

[0068] A portion of the sludge is returned to the flocculation reaction zone 202 for treatment, with a sludge return ratio of 3%-6%.

[0069] Based on the above steps, a portion of the activated sludge at the bottom of sedimentation tank 2 is returned to the flocculation zone through the sludge return pipe to enhance the flocculation and sedimentation effect of the effluent, increase the floc concentration in the flocculation reaction zone 202, increase the probability of floc aggregation, shorten the flocculation time, and also save on flocculant dosage costs. Furthermore, if the sludge return ratio (activated sludge return flow rate / sewage flow rate) is too small, it will not achieve the desired flocculation enhancement effect; if the return ratio is too large, a large amount of sludge will re-enter the reaction tank, increasing the SS concentration in the wastewater, making it difficult for SS in the sedimentation zone 203 to settle effectively, resulting in an increase in the effluent SS concentration.

[0070] It should be noted that the remaining sludge, excluding the reflux sludge, is treated after discharge.

[0071] Furthermore, the nitrogen removal treatment includes: wastewater flowing into denitrification filter 3, and adding a carbon source to denitrification filter 3 to remove total nitrogen from the wastewater.

[0072] In this embodiment, under anoxic conditions, denitrifying bacteria utilize organic matter as electron donors to reduce NO3-N in the water to N2, achieving TN removal. It should be noted that the denitrification filter 3 used in this embodiment is a heteroaerobic denitrification filter 3, requiring external carbon source addition. Sodium acetate is selected as the external carbon source, and the amount added is determined based on the TN and COD (C / N) of the influent to the denitrification filter 3. A low C / N ratio will lead to a decrease in the total number of denitrifying bacteria in the denitrification filter 3, weakening their activity and resulting in poor nitrogen removal; a high C / N ratio will increase the COD of the wastewater, increasing treatment costs. Preferably, the carbon source addition amount suitable for the growth of denitrifying bacteria and wastewater denitrification in the denitrification filter 3 is C / N = 3-5; sodium acetate is added to the influent pipe of the denitrification filter 3 from the carbon source addition point. The filter adopts a downflow mode, and the internal denitrification filter 3 packing 502 is composed of a 3:2 mixture of quartz sand and zeolite.

[0073] Furthermore, the treatment for removing chemical oxygen demand includes:

[0074] The effluent flows to ozone oxidation tank 4 to remove COD. The ratio of ozone dosage to COD in ozone oxidation tank 4 is 0.1-0.4.

[0075] In this step, the ozone oxidation tank 4 is used to remove COD (especially large-molecule, non-biodegradable organic matter), odor, and color from the water. Therefore, the amount of ozone added is determined based on the COD of the influent to the ozone oxidation tank 4. If the ozone dosage is too low (O3 / COD<0.1), the COD removal effect of the wastewater will be low; if the dosage is too high (O3 / COD>0.4), it will result in a waste of resources.

[0076] The water flowing out of the ozone oxidation tank 4 flows to the aerated biological filter 5 for further COD removal. The aeration intensity of the aerated biological filter 5 is 3-5 air-to-water ratio.

[0077] In this step, since the microorganisms in the aerated biological filter 5 need oxygen to grow and reproduce, the amount of oxygen added is determined according to the COD of the influent (air-to-water ratio). If the amount of oxygen added is too low (air-to-water ratio <3), the total number of microorganisms in the filter will decrease, their activity will weaken, and the quality of the effluent will deteriorate. If the air-to-water ratio is too high, the shear force of the water flow will increase, which will easily cause the biofilm in the filter layer to fall off, resulting in a deterioration of the quality of the effluent. In addition, excessive aeration will also increase the treatment cost.

[0078] The present invention also provides a tailwater treatment system, which applies the tailwater treatment method described above to treat tailwater. The tailwater treatment system includes: a wastewater tank 1, a sedimentation tank 2, a denitrification filter 3, an ozone oxidation tank 4, an aerated biological filter 5, a clear water tank 6, and multiple valves. The wastewater tank 1 is connected to the sedimentation tank 2, the denitrification filter 3, the ozone oxidation tank 4, and the clear water tank 6, and corresponding valves are installed on the connecting pipes of the wastewater tank 1 to the sedimentation tank 2, the denitrification filter 3, the ozone oxidation tank 4, and the clear water tank 6. The sedimentation tank 2, the denitrification filter 3, the ozone oxidation tank 4, the aerated biological filter 5, and the clear water tank 6 are connected sequentially, and corresponding valves are installed between the sedimentation tank 2 and the denitrification filter 3, between the denitrification filter 3 and the ozone oxidation tank 4, between the denitrification filter 3 and the clear water tank 6, between the ozone oxidation tank 4 and the aerated biological filter 5, and between the aerated biological filter 5 and the clear water tank 6.

[0079] It should be noted that the aforementioned valves include valve 7 (first), valve 8 (second), valve 9 (third), valve 10 (fourth), valve 11 (fifth), valve 12 (sixth), valve 13 (seventh), valve 14 (eighth), valve 15 (ninth), valve 16 (tenth), valve 17 (eleventh), valve 18 (twelfth), valve 19 (thirteenth), valve 20 (fourteenth), and valve 21 (fifteenth). The connections between these parts are made via pipes, including pipes 22 (first), 23 (second), 24 (third), 25 (fourth), 26 (fifth), 27 (sixth), 28 (seventh), and 29 (eighth).

[0080] The inlet ends of the sewage tank 1 and the sedimentation tank 2 are connected by a first pipe 22, and a first valve 7 is installed on the first pipe 22. The sewage tank 1 and the clear water tank 6 are connected by a second pipe 23, and a second valve 8 is installed on the second pipe 23. The connection point between the first pipe 22 and the second pipe 23 is located between the second valve 8 and the sewage tank 1.

[0081] The outlet of sedimentation tank 2 is connected to the second pipe 23 through the third pipe 24. The third valve 9 and the fourth valve 10 are spaced apart on the third pipe 24. The inlet of denitrification filter 3 is connected to the third pipe 24 through the fourth pipe 25. The connection point between the fourth pipe 25 and the third pipe 24 is located between the third valve 9 and the fourth valve 10. The fifth valve 11 is located on the fourth pipe 25.

[0082] The outlet of the denitrification filter 3 is connected to the second pipe 23 via the fifth pipe 26. The sixth valve 12 and the seventh valve 13 are spaced apart on the fifth pipe 26. The inlet of the ozone oxidation tank 4 is connected to the fifth pipe 26 via the sixth pipe 27. The connection point between the sixth pipe 27 and the fifth pipe 26 is located between the sixth valve 12 and the seventh valve 13. The eighth valve 14 is located on the sixth pipe 27.

[0083] The outlet of the ozone oxidation tank 4 is connected to the inlet of the aerated biological filter 5 through the seventh pipe 28, and the ninth valve 15 is installed on the seventh pipe 28. The outlet of the aerated biological filter 5 is connected to the clear water tank 6 through the eighth pipe 29, and the tenth valve 16 is installed on the eighth pipe 29.

[0084] It should be noted that both the denitrification filter 3 and the aerated biological filter 5 are equipped with a flushing device. The flushing water is taken from the clear water tank 6 through the eleventh valve 17 and the twelfth valve 18, respectively, and the flushing effluent is discharged into the sewage tank 1 through the thirteenth valve 19 and the fourteenth valve 20, respectively. In this embodiment, the second pipe 23 is connected to the eighth pipe 29, and the fifteenth valve 21 is installed on the second pipe 23 near the eighth pipe 29.

[0085] Furthermore, the aerated biological filter 5 is equipped with an aeration device 501 at the bottom, and the packing material 502 of the aerated biological filter 5 is composed of ceramsite. Ozone is generated on-site by an ozone generator 401.

[0086] Furthermore, the sedimentation tank 2 includes a coagulation reaction zone 201, a flocculation reaction zone 202, and a sedimentation zone 203 connected in sequence. The wastewater tank 1 is connected to the coagulation reaction zone 201, and the sedimentation zone 203 is connected to the denitrification filter 3 and the clear water tank 6, respectively. The sedimentation zone 203 is provided with multiple inclined tubes 204, which are spaced apart in the horizontal direction. In this embodiment, the inclined tubes 204 are made of stainless steel or UPVC. A moderately small pore size of the inclined tubes 204 is beneficial to improving sedimentation efficiency, but an excessively small pore size can easily cause sludge blockage inside the inclined tubes 204. The larger the pore size of the inclined tubes 204, the worse the sludge sedimentation efficiency. Preferably, the pore size of the inclined tubes 204 is 50-100 mm. To shorten sedimentation time, increase the effective sedimentation area of ​​wastewater, and improve sedimentation efficiency, the inclined tube 204 extends along its length and is inclined to one side to form a certain angle. The smaller the installation angle, the better the sludge sedimentation effect, but the smaller the angle, the more difficult it will be to discharge sludge. The preferred installation angle is 55-70°.

[0087] Example 1: The influent TP and SS do not meet the discharge requirements, but other indicators do; the "high-efficiency sedimentation tank 2" mode is adopted. Valve 7 (first valve), valve 9 (third valve), valve 10 (fourth valve), and valve 21 (fifteenth valve) are open, and the remaining valves are closed. In this mode, coagulant PAC and flocculant PAM are added to high-efficiency sedimentation tank 2.

[0088] Example 2: The influent TN, TP, and SS do not meet the discharge requirements, but other indicators do; a "high-efficiency sedimentation tank 2 + denitrification filter 3" mode is adopted. Valve 7 (first valve), 9 (third valve), 11 (fifth valve), 12 (sixth valve), 13 (seventh valve), and 21 (fifteenth valve) are open, and the remaining valves are closed. In this mode, coagulant PAC and flocculant PAM are added to the high-efficiency sedimentation tank 2; sodium acetate (carbon source) is added to the denitrification filter 3.

[0089] Example 3: The influent COD does not meet the discharge requirements, but other indicators do; the "ozone oxidation tank 4 + aerated biological filter 5" mode is adopted. Second valve 8, seventh valve 13, eighth valve 14, ninth valve 15, and tenth valve 16 are open, and the remaining valves are closed. In this mode, ozone oxidation tank 4 aerates ozone, and aerated biological filter 5 aerates air.

[0090] Example 4: The influent TN and COD do not meet the discharge requirements, but other indicators do; a "denitrification filter 3 + ozone oxidation tank 4 + aerated biological filter 5" mode is adopted. Valves 8, 10, 11, 12, 14, 15, and 16 are open, and the remaining valves are closed. In this mode, sodium acetate is added as a carbon source to denitrification filter 3, ozone is aerated in ozone oxidation tank 4, and air is aerated in aerated biological filter 5.

[0091] Example 5: The influent TN, TP, SS, and COD all fail to meet discharge requirements; a "high-efficiency sedimentation tank 2 + denitrification filter 3 + ozone oxidation tank 4 + aerated biological filter 5" configuration is adopted. Valve 7 (first valve), 9 (third valve), 11 (fifth valve), 12 (sixth valve), 14 (eighth valve), 15 (ninth valve), and 16 (tenth valve) are open, while the remaining valves are closed. In this configuration, coagulant PAC and flocculant PAM are added to the high-efficiency sedimentation tank 2; sodium acetate (carbon source) is added to the denitrification filter 3; ozone is aerated in the ozone reactor; and air is aerated in the aerated biological filter 5.

[0092] The following table compares the performance of each processing method:

[0093]

[0094] In summary, this invention provides a wastewater treatment method and system. It detects pollutant indicators in the wastewater to reflect the degree of pollution, providing a basis for selecting appropriate treatment methods. Subsequently, based on the types and concentrations of the main pollutants in the wastewater, the most suitable combination of treatment technologies is selected to achieve efficient purification. Finally, the treated wastewater is introduced into a clear water tank 6. This invention, through data analysis, customized treatment strategies, and discharge mechanisms, can flexibly adjust the treatment method according to the effluent conditions, achieving efficient pollution removal and cost savings. Furthermore, by combining different processes according to different wastewater conditions, and controlling the opening of different valves, the wastewater treatment system can achieve efficient pollution removal and cost savings.

[0095] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A method of treating tail water, characterized by, The method comprises the following steps: acquiring parameter data of tail water, the parameter data comprising total phosphorus, solid suspended substance concentration, total nitrogen and chemical oxygen demand; selecting a corresponding tail water treatment mode according to the parameter data, the tail water treatment mode comprising sedimentation treatment, nitrogen removal treatment and / or chemical oxygen demand removal treatment of the tail water; discharging the treated tail water to a clear water pool; the step of selecting a corresponding tail water treatment mode according to the parameter data comprises: when the total phosphorus and solid suspended substance concentration of the tail water do not meet the discharge requirement, performing sedimentation treatment on the tail water; when the total phosphorus, solid suspended substance concentration and total nitrogen of the tail water do not meet the discharge requirement, performing sedimentation treatment and nitrogen removal treatment on the tail water; when the chemical oxygen demand of the tail water does not meet the discharge requirement, performing chemical oxygen demand removal treatment on the tail water; when the content of the total phosphorus, solid suspended substance concentration, total nitrogen and chemical oxygen demand of the tail water does not meet the discharge requirement, performing sedimentation treatment, nitrogen removal treatment and chemical oxygen demand removal treatment on the tail water; the sedimentation treatment comprises: the tail water enters a mixing reaction zone of a sedimentation tank and reacts with a coagulant to polymerize insoluble particles in the tail water to form flocculation alunite flowers; then the tail water carrying the flocculation alunite flowers flows through a flocculation reaction zone and reacts with a flocculating agent, so that the flocculation alunite flowers form flocs; the tail water carrying the flocs enters a sedimentation zone for sedimentation to form supernatant at the upper part of the sedimentation zone; the chemical oxygen demand removal treatment comprises: the tail water flows to an ozone oxidation tank to remove COD, and the ratio of ozone dosage to COD in the ozone oxidation tank is 0.1-0.4; the water flowing out of the ozone oxidation tank flows to a biological aerated filter for further COD removal, and the aeration intensity gas-water ratio of the biological aerated filter is 3-5.

2. The tail water treatment method according to claim 1, characterized by, the coagulant is a polyaluminum chloride or polyaluminum sulfate solution, and the ratio of the coagulant to the total phosphorus of the tail water is 6-15 ((mg / L) / (mg / L)).

3. The method of claim 1, wherein the tail water is treated by a method comprising: the flocculating agent is a polyacrylamide solution, and the ratio of the flocculating agent to the solid suspended substance of the tail water is 0.01-0.06 ((mg / L) / (mg / L)).

4. The method of claim 1, wherein the tail water is treated by a method comprising: the tail water carrying the flocs enters the sedimentation zone for sedimentation, and sludge is accumulated at the bottom of the sedimentation zone, and clear water forms supernatant at the upper part of the sedimentation zone; part of the sludge is backflowed to the flocculation reaction zone for treatment, and the sludge backflow ratio is 3%-6%. the nitrogen removal treatment comprises:

5. The method of claim 1, wherein the tail water is treated by a method comprising: the tail water flows into a denitrification filter tank, and a carbon source is added in the denitrification filter tank to remove total nitrogen in the tail water. application of the tail water treatment method as claimed in any one of claims 1-5 to tail water treatment, the tail water treatment system comprising a sewage pool, a sedimentation tank, a denitrification filter tank, an ozone oxidation tank, a biological aerated filter, a clear water pool and a plurality of valves.

6. A tailwater treatment system characterized by, ​ The sewage pool is communicated with the sedimentation pool, the denitrification filter pool, the ozone oxidation pool and the clean water pool respectively, and corresponding valves are arranged on the connecting pipelines of the sewage pool and the sedimentation pool, the denitrification filter pool, the ozone oxidation pool and the clean water pool; the sedimentation pool, the denitrification filter pool, the ozone oxidation pool, the biological aerated filter pool and the clean water pool are communicated in sequence, and corresponding valves are arranged between the sedimentation pool and the denitrification filter pool, between the denitrification filter pool and the ozone oxidation pool, between the ozone oxidation pool and the biological aerated filter pool, and between the biological aerated filter pool and the clean water pool.

7. The tail water treatment system of claim 6, wherein, The sedimentation pool comprises a coagulation reaction zone, a flocculation reaction zone and a sedimentation zone communicated in sequence, the sewage pool is communicated with the coagulation reaction zone, the sedimentation zone is communicated with the denitrification filter pool and the clean water pool respectively, the sedimentation zone is provided with inclined pipes, the inclined pipes are arranged at intervals along the horizontal direction, the inclined pipes extend along the length direction and are arranged obliquely to one side, the aperture of the inclined pipe is 50-100 mm, and the oblique angle of the inclined pipe is 55-70°.

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