[0013] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention will now be further described with reference to the accompanying drawings.
[0014] The technical scheme of the present invention is a zero-discharge sewage treatment process in the nano-powder industry, including a first-level flocculation tank, a second-level flocculation tank, a sedimentation tank, a battery pool, a disc filter, a positive pressure ultrafiltration filter, Resin filter tanks, RO membrane filter tanks, desalination membrane filters and evaporators. PAC and PAM flocculants are respectively added in the first-level flocculation tank and the second-level flocculation tank to flocculate and settle the nano-powder in the sewage; First class clean water. The first-grade clean water enters the disc filter for filtration to obtain ultrafiltration source water; the ultrafiltration source water is filtered through a positive pressure ultrafiltration filter to obtain ultrafiltration clean water and ultrafiltration concentrated water; the ultrafiltration clean water is passed through the resin filter tank , to obtain demineralized water; pass the demineralized water through the RO membrane filter tank to obtain pure water and softened concentrated water; pass the softened concentrated water through the desalination membrane filter to obtain purified water and concentrated water, and pass the concentrated water through the evaporator to further obtain ultra-clean water and solid waste.
[0015] Based on the above technical solution, the waste water produced in the preparation of ultra-fine powder or the waste water with ultra-fine powder produced in other processes is discharged to the sump for collection, and the large solid waste in it is first removed through primary filtration, etc. Then, the waste water containing ultrafine powder is flocculated through the primary flocculation tank and the secondary flocculation tank, so that the ultrafine powder can be grouped together, the particles increase, and the weight of the flocculation increases, which is conducive to sedimentation and filtration. Then pass the first-grade clean water through the electric pool. According to the principle of electrophoresis, the directional adsorption of the powder that has not been flocculated and precipitated in the water is further realized, and most of the dispersed fine powder in the first-grade clean water is removed, so as to improve the powder removal efficiency and reduce the subsequent The pressure of the filter ensures the working efficiency and service life of each filter. Then, the wastewater is filtered and concentrated step by step to obtain pure water and solid waste. The solid waste can be added as a raw material for other processes or processes. The body is separated from the wastewater to achieve zero discharge of sewage.
[0016] A water collection tank is arranged in front of the first-stage flocculation tank, and a grid and a pre-filter screen are arranged on the water inlet of the water collection tank to realize the filtering and removal of large particles or large volume of solids. Both the primary flocculation tank and the secondary flocculation tank are provided with agitators to ensure that the polyaluminum chloride and polyacrylamide are fully contacted with the ultrafine powder in the wastewater, thereby accelerating and improving the flocculation effect.
[0017] The sedimented sludge enters the plate and frame for extrusion to obtain plate and frame clear liquid and mud cake solid waste. The plate and frame clear liquid is returned to the sump, and the large particle solid waste is directly removed to reduce the filtration pressure of the subsequent filter. , prolong the service life of subsequent filters.
[0018] A clean water tank is also arranged at the back of the sedimentation tank to collect first-grade clean water, and then pump the first-grade clean water into the electric swimming pool. Most of the powder that has not been flocculated and precipitated, obtain secondary clean water, and then enter the secondary clean water into the disc filter at a flow rate of 30t/hour, and set an ultrafiltration source water tank behind the disc filter for temporary storage of the disc. The ultrafiltration source water produced by the type filter, and then the ultrafiltration source water enters the positive pressure ultrafiltration filter according to the flow rate of 40t/hour for filtration, and obtains ultrafiltration clear water and enters the ultrafiltration set at the rear of the positive pressure ultrafiltration filter. The clean water tank, the obtained ultra-filtered concentrated water enters the clean water tank, and then enters the disc filter again. The disc filter adopts a 1um aperture, which has a good filtering effect and also maintains a heightened filtering effect. The positive pressure ultrafiltration filter is adopted to ensure the filtration effect and filtration efficiency, and speed up the efficiency of sewage treatment.
[0019] A booster pump is arranged in front of the resin filter tank, the inlet of the booster pump is connected to the outlet of the ultrafiltration clean water tank, a softened water storage tank is arranged behind the resin filter tank, and an RO is arranged behind the softened water storage tank The high-pressure pump makes the softened water enter the RO membrane filter tank at a flow rate of 40t/hour, and obtains pure water and softened concentrated water. The ratio of pure water and softened concentrated water is 4:1. Through the resin filter tank and RO membrane filter tank, the finer powder in the water body is further filtered to obtain pure water that can be used directly.
[0020] The softened concentrated water enters the desalination membrane filter according to the flow rate of 8t/hour to obtain purified water and concentrated water. Evaporation to obtain ultra-clean water and solid waste. Through evaporation, the more advanced fine powder can be separated to achieve solid-liquid separation.
[0021] The resin filter tank is connected with a backwashing device, and the water outlet of the backwashing device is communicated with the evaporator. Simultaneous treatment of wastewater generated in the process to achieve zero discharge of wastewater.
