Onsite Biological Treatment Of Micro-polluted Source Water Under Conditions Of Lifting Water And Aeration

The biological treatment enhanced by water-lifting aerator was an onsite process for water quality control. The water-lifting Aerator mixed and oxygenated the water body; the biological treatment device could remove the organic matter efficiently in the micro-polluted source water under the conditions of DO concentration, nutrition's transport and turbulence of water body provided by water-lifting aerator. This onsite biological treatment included bacteria-throwing and biological contact oxidation process.In this research, a highly efficient bacterial agent, which was the combination of two aerobic denitrifying bacteria and one facultative denitrifying bacterium, employed for the biological denitrogenation of source water in situ. Besides, based on the experiments, the proper environment for an effective denitrogenation of the agent were characterized by the water temperature of 20℃～30℃,pH of 6.0-8.5 as well as the DO concentration of 0.5-7.5 mg/L.The effectiveness of bacteria-throwing on improving the water quality was proved by the experiment. According to this experiment, the highly efficient bacterial agent could effectively remove the pollution in water. The removal rate of NH4+-N,NO3--N,TN,TP,TOC and CODMn were 93.6%,76.2%,90%,67.6%and 40.6%respectively.This paper also studied on biological contact oxidation process by using a new-type biological packing and the highly efficient bacterial agent. Then the new-type biological packing was cultivated in the culture medium for 3-4 days, as temperature at 25℃～28℃, and DO concentration at 3.0～4.5 mg/L. The experimental study on bio-contact oxidation process showed that the removal rates of NH4+-N,NO3--N,TN,turbidity,TOC and CODMn were 98.5%,76.2%,60%,35.5%and 41%respectively. The pilot experiment study on the biological contact oxidation process enhanced by water-lifting aerator showed that the removal rate of NH4+-N,NO3--N,TN,turbidity,TOC and CODMuwere 100%,83.05%,90.03%,92.3%,92.6%and 89.7%respectively; The pilot experiment study on the bacteria-throwing enhanced by water-lifting aerator showed that the removal rate of NH4+-N, NO3--N, TN, turbidity, TOC and CODMn were 100%,61.71%,79.25%,94.9%,82.16%and 76.42%respectively. The test result of the biomass reflects that the number of the added denitrifying bacteria kept stable, which verifies the dominate position of the agent in the system.