Research On The Treatment Of Wastewater Treatment Plant Secondary Effluent By Using Flocculation Sedimentation-cloth-media Disk Filter And Sedimentation Numerical Simulation

According to statistics, more than300towns are short of water in China, and the shortage of water resources has restricted some region’s economic development and social. It is of great significance for wastewater treatment plant to make the effluent quality meet the new standard to alleviate water environment worsening. This topic is about the strengthening treatment of sewage plant secondary effluent in Sunshine Campus of Wuhan Textile University by using flocculation-micro filter cloth filter technology and the research on plane filtering mechanism. We gain the primary equipment operating parameters and the simulation results of tank of the flow field.In jar tests, the optimum dosages of PAC were15.5mg/L,17.7mg/L,22.2mg/L respectively to remove the three low turbidity raw water (20NTU,30NTU,40NTU). The optimum value of pH is7, that is, the best coagulation effect of PAC is under neutral and alkaline conditions.Using flocculation-micro filter cloth filter technology can effectively remove sewage of TP and suspended matter, but for CODcr、TOC and TN removal effect is not good. The removal rate of TN increase with the increase of the dosage of PAC. Controling the right chemical dosage consumption, back washing intensity and line speed of driver is the key of the system operation. The optimum dosage of PAC is3mg/L, the best back flushing intensity is3.5L/(m2·s), and the best line speed of driver is2.09m/s. The technology is a kind of economic and feasible process as the urban sewage treatment plant secondary effluent subsequent advanced treatment unit.The velocity vector field of horizontal sedimentation tank and plate sedimentation tank is provided by using Fluent. We can visually analyze the speed variation of the inclined plate sedimentation tanks, that is,the mainstream speed of inclined plate sedimentation tanks increases, the following features of particles enhance, while the settlement path shortens and solid-liquid separation effect is very good.We calculate the Reynolds number of the water flow in the plate sedimentation tanks. The Reynolds number of water flow can significantly reduce by joining the inclined plate. And the water flow is in a laminar flow state.The results show that the filter cloth filter is powered by mechanical adsorption and physical chemical filtration. The flocculation-micro filter cloth filter technology is a kind of economic and feasible process as the urban wastewater treatment plant secondary effluent subsequent advanced treatment unit.