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This thesis BAF existing problems and pollution of water resources status quo, with Jiaxing organics, ammonia and manganese composite polluted water features, carried out on ceramic, volcanic zeolite / carrier combination lightweight filler comparison study aims to provide BAF heavily polluted raw water pretreatment method. Heavily polluted by laboratory simulation of the raw water quality, dual-stage study BAF, single-stage and single-stage ceramic volcanic BAF, the hydraulic loading 2m ~ 3 / m ~ 2 · h, air-water ratio 1:1, temperature about 25 ℃, pH value of 6.5 to 7.5 when running stable removal efficiency. Studies show that two-stage and single-stage BAF ceramic, single-stage volcanic BAF compared with stronger remove organics, ammonia and manganese performance, the average removal rates were 39.64%, 90.70% and 94.5%. Also has a strong biological stability and security, particle size 3 ~ 15μm particle removal rate above 55%. Coagulation combination with synergistic strengthening effect, coagulant dosing 20mg / L for potassium permanganate index average removal rate was 66.67%. Based on two-stage BAF efficient removal efficiency of pollutants, in-depth study of the hydraulic loading, gas-water ratio, temperature, pH, pollution load, backwash filter close other factors on the two-stage BAF Operation of the test results showed that: the hydraulic loading 1.5 ~ 2m ~ 3 / m ~ 2 · h, the gas-water ratio of 1:1, the temperature 20 ~ 30 ℃, pH value of 7.0 to 8.5 for the filter optimum operating parameters. In the optimum operating conditions, the filter for ammonia and manganese composite pollution shock load ability, remains efficient removal efficiency, but organic pollution load of the ammonia removal efficiency decreased to around 60%. Backwash the best parameters are: backwash cycle different levels of water pollution by 15 ~ 45d, for the joint air and water backwash backwash. The intensity of the first gas washing 5L / m ~ 2 · s, washing time is 15min, washed separately after a strength of 5L / m ~ 2 · s, the rinsing time is determined as a 3min. Filter Close 28d restart, 8h restore capabilities for removal of organic matter, ammonia nitrogen removal capacity by the filter off little impact. Two-stage BAF characterized by: the filter subordinate to lightweight materials for the carrier, using 1 ~ 2mm higher pore zeolite. It has the advantages that: Lightweight carrier rely filter aeration and hydraulic lift inside the mixing, the bottom is in a suspended state, the central state in the extrusion filter, the upper in a fluidized state. Suspended state to avoid the water side surface of the filter layer of sludge layer formation, extruded carrier rejection filter to play role in making clinoptilolite avoid suspension of its surface parcels and clogged pores, can efficiently play nitrification role and adsorption. Two-stage BAF can achieve overall coordination of organic matter and ammonia efficient removal effect. The main results of this paper will be a national water pollution control and management of major science and technology, \Pretreatment of polluted water applications provide the technical basis.
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