Novel hospital wastewater treatment system and wastewater treatment method

Abstract

The invention discloses a novel hospital wastewater treatment system and a novel hospital wastewater treatment method. An anoxic, aerobic and MBR treatment process is adopted. Comprising a grating, an adjusting tank, an anoxic tank, an aerobic tank, an MBR reaction tank and a disinfection tank which are sequentially connected, the MBR reaction tank is respectively communicated with a sludge storage tank and a sludge concentration tank, and the sludge concentration tank is communicated with the anoxic tank. According to the technical scheme, the hospital wastewater treatment device can adapt to different seasons, the hospital wastewater treatment device has a good treatment effect on hospital wastewater, and the effluent quality index meets the Discharge Standard of Water Pollutants for Medical Institutions (GB 18466-2005). The whole process has the advantages of good treatment effect, simple process, small occupied area, stable operation, low energy consumption, less sludge output and better practical feasibility.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, and in particular to a novel hospital wastewater treatment system and a wastewater treatment method. Background Art

[0002] Hospital wastewater has complex sources and components, including pathogenic microorganisms, toxic and harmful physical and chemical pollutants, and radioactive pollution. If hospital wastewater containing pathogenic microorganisms is directly discharged into urban sewers without disinfection, inactivation and other harmless treatments, it will often cause water and soil pollution, and in severe cases, it will cause various diseases or lead to the outbreak of waterborne infectious diseases. Therefore, the treatment of hospital wastewater is necessary.

[0003] At present, the treatment of hospital wastewater in China mainly adopts A / O method, MBR method, CASS method, coagulation flocculation and flotation, ultraviolet method, chlorination method, aerated biological filter method, SBR method and other methods. Among them, MBR treatment method has high removal rate, low operating cost, improved effluent quality, almost no residual dirt, compact size, low power consumption. And it can produce clean energy and has strong biodegradability. It is feasible to use MBR treatment method. It is relatively easy for MBR reactor to produce granular sludge, but MBR reactor has high operating cost, which makes membrane technology look unreliable, and there is only a short operating time between cleaning cycles, resulting in low treatment efficiency. Summary of the invention

[0004] The present invention aims at the shortcomings of the existing methods and provides a novel hospital wastewater treatment system to solve the problems of long hospital wastewater treatment reaction time and low efficiency in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a new hospital wastewater treatment system, comprising a regulating tank, an anoxic tank, an aerobic tank, an MBR reaction tank and a disinfection tank connected in sequence, the MBR reaction tank is connected to the anoxic tank and the sludge storage tank respectively, and the sludge thickening tank is connected to the sludge storage tank and the anoxic tank respectively.

[0006] The wastewater treatment method based on the new hospital wastewater treatment system adopts the treatment process of anoxic + aerobic + MBR, including the following steps: 1) Wastewater enters the screen, retaining and removing larger particles of suspended matter and floating matter; 2) After passing through the screen, the wastewater enters the regulating tank, where the water quality and water volume are adjusted to ensure the stability of the water quality and water volume entering the biochemical pool system; 3) The wastewater regulated by the regulating tank enters the anoxic tank for anaerobic reaction, which improves the COD removal rate, converts high-molecular-weight, difficult-to-degrade organic matter into low-molecular-weight, easily degradable organic matter, and increases the COD / BOD ratio, which plays a role in denitrification to remove nitrate nitrogen, while removing part of the BOD, and also has the effect of hydrolysis reaction to improve biodegradability; 4) The wastewater after the reaction in the anoxic tank enters the aerobic tank, so that most of the organic matter is degraded in the aerobic tank, and the ammonia nitrogen is nitrified and degraded inside the aerobic tank; 5) The wastewater treated in the aerobic tank enters the MBR reaction tank, and the membrane is used to trap microorganisms and sludge impurities in the reactor; 6) The wastewater filtered by the MBR reaction tank enters the disinfection tank and is discharged after being tested and meeting the standards; 7) The sludge produced by the MBR reaction tank in step 5) enters the sludge storage tank and the sludge thickening tank for dehydration treatment. After the sludge is treated, it is transported out in a centralized manner, and the supernatant and filtrate in the thickening tank are returned to the sewage treatment system.

[0007] Preferably, the MBR reaction tank is also connected to a powdered activated carbon dosing device.

[0008] Preferably, the MBR reaction tank includes a membrane separation component and a bioreactor.

[0009] Preferably, it also includes a grille, which is located in front of the entrance of the regulating tank and is a mechanical grille.

[0010] Preferably, the anoxic tank is a mixed anoxic tank.

[0011] Preferably, the aerobic tank is a biological contact oxidation tank.

[0012] Preferably, the MBR reaction tank uses a KH-MBRP-80-PVDF flat membrane module membrane.

[0013] Preferably, the sludge storage tank and the sludge thickening tank form a side stream excess sludge unit treatment tank.

[0014] Compared with the prior art, the beneficial technical effects of this application include: 1. This new hospital wastewater treatment system scientifically and accurately controls the process according to the concentration of organic pollutants in the influent and the changes in the reaction rate of activated sludge of different dominant bacteria in each functional area. Through scientific analysis and evaluation, design or transformation of the water flow mode in the pretreatment section, the process can be flexibly adjusted to achieve efficient removal of various pollutants at high influent organic concentrations in an economical, efficient and stable manner; 2. It can effectively remove organic matter in water, including refractory organic matter and micro-pollutants, and improve the treatment effect of wastewater; 3. Absorb odorous substances in water to improve the quality of treated water; reduce membrane pollution and scaling, extend the service life of the membrane, and reduce maintenance costs; through the adsorption of activated carbon, the water treated by the MBR system is clearer, cleaner, and more suitable for reuse; 4. The wastewater treatment method of this application has a scientific principle, is simple to operate, and is convenient to run and manage. It is fully applicable to large, medium and small hospitals with high concentrations of organic pollutants in the influent. It is the first time in practice that a targeted and operable method has been proposed to address the common problems in this industry; 5. If the effluent of the treatment system of this application is added with a deep treatment unit, it can meet the reuse water standard. The large-scale use of reclaimed water in the production process can greatly reduce the production cost and conform to the development concept of green environmental protection. In addition, it can optimize and upgrade the process of existing hospital wastewater treatment plants with complex pollutant components and high organic matter concentrations through simple process modification and the addition of some facilities, and it can also be directly used in the process design of new hospital wastewater treatment plants involving high influent organic pollutant concentrations; 6. In view of the possible shortcomings in the treatment effect, the traditional MBR method is updated to an AO-MBR sewage treatment system using powdered activated carbon. On the basis of traditional AO, MBR is combined with powdered activated carbon to improve the removal effect of pollutants, especially difficult-to-degrade organic matter and humus-like organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of a hospital wastewater treatment device in an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0017] 1. A highly efficient hospital wastewater treatment system refer to Figure 1As shown, a novel hospital wastewater treatment system comprises a grid 1, a regulating tank 2, an anoxic tank 3, an aerobic tank 4, an MBR reaction tank 5, and a contact disinfection tank 6 connected in sequence. The outlet of the regulating tank 2 is connected to the inlet of the anoxic tank 3, the outlet of the anoxic tank 3 is connected to the inlet of the aerobic tank 4, the outlet of the aerobic tank 4 is connected to the inlet of the MBR reaction tank 5, and the MBR reaction tank 5 comprises a separation component and a bioreactor. Wastewater enters the reaction zone from the bottom of the MBR reaction tank 5, enters the sedimentation zone after gas-solid-liquid three-phase separation, the gas after gas-solid-liquid separation is collected by the gas chamber, and the sludge automatically returns to the reaction zone from the sedimentation zone through the sludge return seam. The outlet of the MBR reaction tank 5 is connected to the inlet of the contact disinfection tank 6, and the sludge derived from the MBR reaction tank 5 flows back to the anoxic tank 3. The sludge storage tank 7 is located below the regulating tank 2, and the sludge in the MBR reaction tank flows to the sludge storage tank 7. The outlet of the sludge storage tank 7 is connected to the sludge concentration tank 8, and the outlet of the sludge concentration tank 8 is connected to the excess sludge treatment, and the supernatant of the sewage in the sludge concentration tank 8 is returned to the anoxic tank 3. The anoxic tank 3 is a mixed anoxic tank.

[0018] (II) A highly efficient method for treating hospital wastewater When the novel hospital wastewater treatment system provided by the present invention is in operation, the hospital wastewater first flows to the grid 1 after confluence, the main purpose of which is to remove floating pollutants, and then enters the regulating tank 2. The function of the regulating tank 2 is to regulate the water quality and quantity. The water from the regulating tank 2 passes through the anoxic tank 3. The function of the anoxic tank 3 can promote the degradation of organic matter and the removal of nitrogen and phosphorus, which is beneficial to improving the sewage treatment efficiency and purifying the water quality. The water from the anoxic tank 3 enters the aerobic tank 4 from the bottom of the aerobic tank 4 by a sewage lifting pump and undergoes aerobic oxidation to reduce the concentration of organic matter in the water. The MBR reaction tank 5 includes a membrane separation component and a bioreactor. After the wastewater enters the reaction zone, the activated sludge and macromolecular organic matter in the interception tank of the membrane separation equipment immersed in the aerobic biological tank are used. The generated gas enters the gas chamber and enters the sedimentation zone after gas-solid-liquid three-phase separation. The gas after gas-solid-liquid separation is collected by the gas chamber, and the sludge automatically returns to the reaction zone from the sedimentation zone through the reflux seam, so that the reaction zone can maintain a high biomass. In order to provide sufficient oxygen, improve mass transfer efficiency, prevent sludge deposition, and maintain a uniform mixing state, the MBR reaction tank 5 needs to be equipped with a stirring device. The MBR process not only saves the construction of the secondary sedimentation tank, but also greatly improves the solid-liquid separation efficiency by organically combining the membrane separation technology in the separation project with the traditional wastewater biological treatment technology. In addition, the biochemical reaction rate is increased due to the increase in the concentration of activated sludge in the aeration tank and the appearance of special bacteria (especially dominant bacteria) in the sludge. After the sewage leaves the MBR reaction tank 5, it directly enters the contact disinfection tank 6. The contact disinfection tank is mainly used to disinfect and remove chlorine from the water treated by the MBR system, and also plays a certain role in pH adjustment, buffering and water storage. The sludge storage tank 7 collects the sludge generated in the MBR reaction tank 5. After the sludge leaves the sludge storage tank 7, it enters the sludge concentration tank 8, where it is concentrated. The concentrated sludge is loaded and transported to the outside of the factory for proper disposal. The sewage supernatant in the sludge concentration tank 8 returns to the anoxic tank 3. The water flowing out of the MBR reaction tank 5 enters the contact disinfection tank 6, where it is disinfected by chlorination, that is, the effluent water quality can meet the standard.

[0019] The anoxic pool 3 described above is a mixed anoxic pool, and the aerobic pool 4 described above is a biological contact oxidation pool.

[0020] The disinfection pool 6 described above uses sodium hypochlorite to disinfect the effluent, and the disinfection contact time is 30 minutes.

[0021] The MBR reaction tank 5 is also connected to a powdered activated carbon dosing device. Powdered activated carbon (PAC) is a natural humus substance that can still adsorb dichlorophenol (DCP) after saturation. In the continuous operation test, it was further verified that the ability of PAC-MBR to resist DCP shock load is stronger than that of MBR with ordinary fillers. By measuring the apparent molecular weight distribution of influent and effluent organic matter, it was found that PAC-MBR can effectively remove organic pollutants of 1 to 4K (1K=1000um). The removal of 4K to 0.45μm organic matter is related to the saturation of PAC, and the removal rate gradually decreases with the extension of operation time. Both PAC-MBR and ordinary filler-MBR can effectively remove biodegradable organic matter. The removal rate of the former for adsorbable organic matter is greatly affected by the saturation of PAC. The results of oxygen consumption rate measurement show that the microbial activity in PAC-MBR is slightly higher than that of MBR with ordinary fillers. In order to make full use of the adsorption capacity of powdered activated carbon, it is advisable to use powdered activated carbon with a mesh size greater than 250; but at the same time, the turbidity of the sedimentation tank effluent must be strictly controlled to about 1NTU, and the filtration rate of the filter tank must be strictly controlled.

[0022] The hospital wastewater treatment device of the present invention has a good treatment effect on hospital wastewater, and the effluent water quality index meets the "Medical Institution Water Pollutant Discharge Standard" (GB 18466-2005). The entire process has good treatment effect, simple process, small footprint, stable operation, low energy consumption, and less sludge generation, and has good practical feasibility.

[0023] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A new hospital wastewater treatment system, characterized by: The invention comprises a regulating tank (2), an anoxic tank (3), an aerobic tank (4), an MBR reaction tank (5) and a disinfection tank (6) which are connected in sequence. The MBR reaction tank (5) is connected to the anoxic tank (3) and the sludge storage tank (7) respectively, and the sludge concentration tank (8) is connected to the sludge storage tank (7) and the anoxic tank (3) respectively.

2. A wastewater treatment method based on the novel hospital wastewater treatment system according to claim 1, characterized in that: The treatment process of anoxic + aerobic + MBR is adopted, which includes the following steps: 1) Wastewater enters the screen (1), which retains and removes larger particles of suspended matter and floating matter; 2) After passing through the screen (1), the wastewater enters the regulating tank (2), where the water quality and water quantity are regulated to ensure that the water quality and water quantity entering the biochemical tank system are stable; 3) The wastewater regulated by the regulating tank (2) enters the anoxic tank (3) for anaerobic reaction, which improves the COD removal rate, converts high-molecular-weight, difficult-to-degrade organic matter into low-molecular-weight, easily degradable organic matter, and increases the COD / BOD ratio, thereby removing nitrate nitrogen through denitrification and removing part of the BOD. It also has the effect of hydrolysis reaction to improve biodegradability. 4) After the reaction in the anoxic tank (3), the wastewater enters the aerobic tank (4), so that most of the organic matter is degraded in the aerobic tank (4), and at the same time, the ammonia nitrogen is nitrified and degraded in the aerobic tank (4); 5) The wastewater treated in the aerobic tank (4) enters the MBR reaction tank (5), where the membrane is used to trap microorganisms and sludge impurities in the reactor; 6) The wastewater filtered by the MBR reaction tank (5) enters the disinfection tank (6) and is discharged after being tested and meeting the standards; 7) The sludge produced by the MBR reaction tank (5) in step 5) enters the sludge storage tank (7) and the sludge thickening tank (8) for dehydration treatment. After the sludge is treated, it is transported out in a centralized manner, and the supernatant and filtrate in the thickening tank are returned to the sewage treatment system.

3. A novel hospital wastewater treatment system according to claim 1, characterized in that: The MBR reaction tank (5) is also connected to a powdered activated carbon dosing device.

4. A novel hospital wastewater treatment system according to claim 1, characterized in that: The MBR reaction tank (5) includes a membrane separation component and a bioreactor.

5. A novel hospital wastewater treatment system according to claim 1, characterized in that: It also comprises a grille (1), wherein the grille (1) is located in front of the inlet of the regulating tank (2), and the grille (1) is a mechanical grille.

6. A novel hospital wastewater treatment system according to claim 1, characterized in that: The anoxic pool (3) is a mixed anoxic pool.

7. A novel hospital wastewater treatment system according to claim 1, characterized in that: The aerobic tank (4) is a biological contact oxidation tank.

8. A novel hospital wastewater treatment system according to claim 1, characterized in that: The MBR reaction tank (5) uses a KH-MBRP-80-PVDF flat membrane module membrane.

9. A novel hospital wastewater treatment system according to claim 1, characterized in that: The sludge storage tank (7) and the sludge thickening tank (8) form a side stream excess sludge unit treatment tank.

Images