Sewage denitrogenation dephosphorylation treatment method by using biological film to filter

Abstract

The invention relates to a sewage denitrification dephosphorization treatment method which uses biologic film to filter, wherein the invention arranges a biologic film filter in an aeration tank, which uses stainless steel or filter cloth as screen to replace traditional two deposit tanks to separate sludge and water. The invention is characterized in that the average aperture of stainless steel or filter cloth screen of the biologic film filter is 10-200mum, the screen is arranged with a biologic film to stop active sludge, the water flux at unit screen can reach more than 100l / h.m2, the highest filter resistance is controlled under 0.5m, the sludge of aeration tank can reach at least 2-3 times of general one, and the phosphor in the outlet water filtered by the biologic film filter is flocculated and deposited to reach denitrification and dephosphorization demands, the resistance of biologic filter is increased when serves some time, while the water flux is reduced, and the biologic film filter can come back to normal running after being blown reversely and washed reversely via a water pump.

Description

Technical field: [0001] The invention relates to the technical field of sewage treatment, in particular to a method for denitrification and dephosphorization of sewage by using biofilm filtration instead of secondary sedimentation tanks to retain activated sludge in the process of sewage activated sludge treatment. Background technique: [0002] Serious water pollution and shortage of water resources have seriously affected the sustainable development of my country's economy. The sharpening of environmental pollution and water eutrophication has forced more and more countries and regions to formulate strict nitrogen and phosphorus discharge standards. A large number of studies have proved that, Nitrogen and phosphorus in sewage are one of the main causes of eutrophication in receiving water bodies. Conventional sewage treatment technology mainly removes organic matter and suspended solids, and the removal efficiency of nitrogen and phosphorus is low. Many developed countries ...

AI Technical Summary

Problems solved by technology

Due to the small pore size of the current ultrafiltration membrane or microfiltration membrane treatment device, the membrane flux is generally 15-20l / h.m 2 , the water flux per unit area is relatively low, so the surface area of ​​the membrane device for treating unit sewage volume is large. In addition, at the same time, the resistance of the membrane is relatively large during operation, and the resistance of the membrane during operation can reach up to 5-8m, resulting in high energy consumption during operation. After a period of time, conventional physical backwashing is difficult to restore water flux, and regular chemical cleaning is required to effectively restore water flux

At the same time, due to the large surface area of ​​the membrane and the high cost of the membrane module, the engineering investment of the membrane treatment device is significantly larger than that of the traditional treatment technology, and the operating cost is increased, which limits the application of the membrane bioreactor technology. The removal efficiency is poor

It can be seen that the use of membrane bioreactors has limited popularization and application due to high operating costs, low flux of membrane devices, and high engineering investment.

Images