Study On The Process Of Coagulation Sedimentation+Mbbr In Treatment Of Tungsten Smelting Wastewater

In the thesis, waste water from a tungsten smelting plant in Jiangxi province, include waste water from adsorption process, negative wash process, shop floor washing process, sewage etc. have been studied. Waste water from desorption and liquor treatment process was recycled via ion exchange and evaporation crystallization. After that, almost no wastewater discharged. Based on properties of wastewater, a combination treatment process have been proposed. COD、BOD、 NH3-N、SS were considered as a major indicators to evaluate effects of each processing units and their combined process respectively.Coagulation sedimentation has a great capacity of accommodation, which could efficiently decrease load of after treatment. Removal of COD and SS could be reached nearly28%and60%respectively during normal operation of coagulation tank.Moving Bed Biofilm Reactor(MBBR) technology, based on fluidized bed technologies, with a combination of suspended activated sludge and attached biofilm process, is becoming a state-of-the-art efficient reactor. As a practical technology for municipal wastewater treatment, with efficient, compact, cost-effective, flexible and trouble-free characteristics, MBBR has attracted extensive attention.MBBR reactor using the sludge of municipal wastewater treatment plant as seeding sludge,and forming biofilm could be accomplished within2weeks. It was found that MBBR reactor exhibits a good effect in waste water treatment of tungsten smelting plants. During normal operation of the reactor, removal of COD ranged from80%to87%, removal of NH3-N could be reached70%.The wastewater from MBBR reactor through coagulation and sedimentation, ensure water quality satisfies the standard of grade1in Integrated Wastewater Discharge Standard (GB8978-1996). During actual operation, COD, BOD, NH3-N and SS are all below100mg/L,20mg/L,15mg/L,70mg/L respectively in the effluent.