Experimental Study On The Biofilm Characteristics Of Contact Biological Oxidation

Municipal sewage of Zhenjiang city adopts the collection mode of rain water, for reducing the pollution of inner river, the project team carried on pollution control and studies on ecological restoration in dadonggou. The technology of pollution control main adopts biological contact oxidation technology. The mechanism for the purification of the biological contact oxidation technology shows that the removal of solubility substance has relation to the biofilm, so the paper combined "The tenth five years' plan", studied the biofilm characteristics about biofilm mass, biofilm oxygen consumption rate, polysaccharide, bacterium count, settleability and biofacies etc under different carriers, culture mode, temperature, pH and nutrition proportion mainly, for adopting biological contact oxidation technology provides feasibility gist.The main conclusion as followed: the cubic carrier performs fine, its special material and good function of water and gas distribution makes the bioflm holding favorable activity and variability of lacuna, gets more and more specific surface area during the operation period, and its back flushing effect is fine, the service life of padding can be prolonged and the disposal cost can be reduced; when the temperature was higher than 20℃, the effect of hanging membrane naturally was better than the effect of vaccination hanging membrane; when the temperature was low, the time of vaccination hanging membrane succeeded was short; the biological contact oxidation technology has relatively strong anti-shock ability, when the pH was 4～10, the effluent pH was about 6.3～8. The microorganism developes well in neuter or alkaline condition, the biofilm has good activity, the value was about 0.0085 mgO₂/(mgMLVSS.h); when the temperature were 25℃and 17℃, the combination property of the biofilm was very good. Although when the temperature was high, the removal efficiency was good; when the C:N:P was 100:5:1, the content of biofilm polysaccharides was high, the value was about 0.3247 g/gMLSS, when the C:N:P was 200:5:2, the combination property of the biofilm was good too, but the biofilm massis high; basing on mass transfer and reaction theoretics builded a model was the expression of reactionkinetics. The results of sensitivity analysis showed that maximum specific growth rate^μH, K_STO, biofilm surface area, biofilm mass, biofilm thickness L_f had big impact on the effluent COD_Cr, the value of sensitivity were greater than 1, K_STO was 5.35.