A Study On Pretreatment Of Micro-Polluted Raw Water By Low-Power Sbbr

For the current problems of increasingly polluted surface water, this article examines the application of Sequencing Biofilm Batch Reactor (SBBR) for the pretreatment of micro-polluted raw water to solve the problems of high air-water ratio and poor removal efficiency at low temperature during the micro-polluted water pretreatment process of biological pretreatment.Using ceramsite with crack surface as the filling material, SBBR was investigated to pretreat the micro-polluted source water of a river. By changing the aeration rate and the aeration time for different air-water ratio, the effect of air-water ratio on the removal efficiency had been researched. The stable removal efficiency under low air-water ratio and low temperature had been studied in this paper.Ceramsite with crack surface was conducive to the biofilm formation and microbial growth that biofilm formation was successful in20days. The SBBR maintained in good removal efficiency when the air-water ratio was between4:1-0.125:1, and had stable removal efficiency at the air-water ratio of0.125:1over four months. The removal efficiency of turbidity、CODMn and ammonia nitrogen was77%、45.1%and90.4%, which indicated that the SBBR still had good removal efficiency at low air-water ratio. When the air-water ratio was0.25:1and the temperature between4～10℃, the average removal efficiency of turbidity, CODMn and ammonia nitrogen was65.3%,35.4%and87.7%, respectively. The result proved that the removal of ammonia nitrogen was maintained in good efficiency at low temperature.Due to the sequencing batch operation, uniform distribution of the microorganisms, no clogging, no backwashing and much amount biomass that was good for the long generation microorganism growth, which was conducive to maintain high removal efficiency of pollutants in the low-power SBBR. The results of SEM showed that well-distributed biofilm had been formed around the ceramsite. DGGE analysis indicated that the microbial species and biomass was diversity and stable under the condition of different air-water ratios and temperatures.