| MBBR is a new way of biofilm water treatments, which is got more and more attention for its advantages and characteristics. Compared with activated sludge process, MBBR has many advantages, such as high treatment efficiency, less surplus sludge and no sludge fulmination bulking and so on. With the deterioration of eutrophication problem, water-quality index architecture is stricter. So, the problem of waster nitrogen and phosphorus removal has been comprehensive studied in control of water pollution, especially to the domestic sewage of Guangdong Province, what having characteristics of low concentrations of COD but high concentrations of TN and TP.A type of specific MBBR for the treatment of simulated municipal wastewater was used to study the removal of COD, TN and TP. And through changing fill rate, HRT and the water-gas ratio, we can research the removal efficiencies of MBBR to COD, TN and TP on the different conditions, upgrade the operation condition of the reactor, so we can make a reference in practical application.Under the condition of influent COD, TN and TP concentration of 200mg/L,10 mg/L and 2mg/L respectively, the processing capacity of the reactor under various conditions was investigated. The results showed that, (1) at ordinary temperatures, the processing capacity of the reactor was rising with the increasing of fill rate, the removal efficiencies of COD, TN and TP were 79.94%,43.91% and 49.33% when the fill rate was 40%. (2) With the increasing of HRT, the processing capacity of the reactor was also growing, the removal efficiencies of COD, TN and TP were 91.35%,50.26% and 56.57% when the HRT was ten hours. (3) With increase of oxygen supply, the use of oxygen was improved. But a strong aeration led to a decrease of oxygen utilization ratio. The suitable ratio of water-gas was aboutl:18. (4) pH was one of the key parameters which have effect on removal efficiency; the processing capacity of the reactor would decline when pH was less than 5 or more than 9. (5) The reactor had a high toleration to shock load and it could keep the effluent quality stable. When the COD was changed from 200mg/L to 300mg/L even 400mg/L, the removal efficiency still could reach more than 80% after some days. When TN has risen from 10mg/L to 20mg/L and 30 mg/L suddenly, the removal efficiency was about 40%. The removal efficiency of TP has just fallen some percent when TP has changed from 2mg/L to 3mg/L and 4mg/L.Compared with A/O process of Lijiao sewage treatment plant, the removal efficiencies in MBBR were better than A/O except TP, the main effluent quality after coagulation attained Municipal Wastewater Treatment Plant Emission Standards (GB18918-2002)... |
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