Study On The Treatment Of Uasf And Biological Contact Oxidation Process For Domestic Sewage

With the development of sub zone and increasing greening area, decentralized treatment and reuse for domestic sewage become a tendency. Besides high effeciency of treatment and small volume equipment, it needs avoiding second-contaminated problem for construction and operation of treatment facilities.Domestic sewage of Shenyang University is used in the essay, and anaerobic-aerobic treatment is advanced.Through the series of condition experiments, the best treatment conditions are definited.In UASF reactor pH,temperature,mixed liquor reflux are experiment parameters. Conclusion indicates that during the hydrolytic acidification stage of the startup period, pH does not need to be adjusted. The methanogensis stage is heavily influenced by the pH level.When the mixture of Na2CO3 and NaHCO3 is used to adjust pH to between 6.8 and 7,2.During the startup period, temperature has a slight influence on the hydrolytic acidification stage, but a significant influence on the methanogensis stage.The optimal temperature of the methanogensis stage is 30°.When mixed liquor reflux is not arranged in the hydrolytic acidification stage and arranged in the methanogensis stage, the optimal reflux method includes2-h interval 10-s reflux period.If the above mentioned optimization measures are applied, the startup time of the combined anaerobic reactor can be shortened to less than 30 days,which is approximately the one third to one sixth of the traditional process (3 to 6 months).The operation efficiency of the combined anaerobic reactor is remarkably improved. Through the treatment of UASF reactor, the removal rate of COD can reach more than 80%, and the concentration of COD can become less than 100mg/L.When effluent of anaerobic treatment sewage is treated by aerobic treatment, the concentration of COD can become less than 30mg/L, and the removal rate of nitrogen can reach more than 60%,and the concentration of nitrogen can become about 20mg/L. Tthe removal rate of phosphorus can reach more than 90%,and the concentration of phosphorus can become about 1.0mg/L.The removal rate of SS can reach between 80% and 90% stably, and the concentration of SS can become lOmg/L.UASF and biological contact oxidation process are used to treat domestic sewage. The total removal rate of effluent COD can reach above 96%,and the concentration of effluent COD can become less than 30mg/L.The total removal rate of nitrogen can reach more than 60%,the concentration can become about 20mg/L.The total removal rate of phosphorus can reach more than 80%,and the concentration can become about 1.0mg/L. The total removal rate of SS can reach between 80% and 90% stably, and the concentration can become 10mg/L. It can meet to(GB/T18920-2002) greening water stardard.