Name： Complete solution of municipal wastewater
Municipal wastewater mainly includes domestic wastewater and moderate industrial wastewater that discharged by household, government, commercial, urban public facilities, etc. The water volume of wastewater is large and there are significant changes of circadian periodicity and seasonal periodicity. Main pollutants in wastewater include animal and vegetable oil, suspended matters, carbohydrate, protein, surfactant, nitrogen and phosphorus compounds, microorganisms, etc. Generally, these organic pollutants are easier to be biodegraded. The value of BOD/COD reaches 0.5~0.6, and it also contains nitrogen and phosphorus and other nutrients, what provide good growing environment for organism.
Municipal wastewater is treated mainly by biochemical treatment methods, including activated sludge process, biological membrane process, bio filter, oxidation ditch and other methods. It mainly includes pretreatment system, multistage aeration biological tanks, post-processing system. Typical process: coarse screen→ fine screen →grit chamber→ anoxic tank → aerobic tank→ secondary sedimentation tank→ advanced treatment→ disinfection tank → discharge. However, this process has several technical problems, including high capital expenditure, high operation cost, large energy consumption, complex management, easy to turn up sludge expansion, and difficult to reach the standard of nitrogen, phosphorus and other nutrients.
Developed by BODA, membrane bioreactor(MBR)is one kind of new wastewater treatment technology that combined with efficient membrane separation technology and activated sludge process. It can be used for treating municipal or industrial wastewater with high content of organics. MBR can make the activated sludge have higher MLSS, and prolong the time of its stay in the reactor to improve the removal rate of nitrogen and the degradation of organic matter. At the same time, it replaces the traditional sediment process with solid-liquid separation process through membrane module, which can effectively remove solid suspended particles, organic particles and prepare sterile water.
Compared to the traditional process, MBR owns the following advantages：
(1)It can save 50% of land area, and the capital expenditure is lower;
(2)High sludge concentration(10g/L)and longer sludge retention time (≮30 days).
(3)Stable produced water quality for different influent;
(4)Less sludge production, which reduces the cost of subsequent sludge treatment;
(5)Lower energy consumption, easier operation, lower operation costs