内循环对Orbal氧化沟系统生物脱氮除磷的影响

试验采用实际生活污水,利用改进的Orbal氧化沟中试系统(其中,氧化沟主体容积460L),在低溶解氧条件下研究了内循环对系统的影响,实现了良好的脱氮除磷效果.增加内循环回流比,可以增强系统对氨氮负荷的抗冲击能力,提高脱氮效果,但是除磷效率降低.考虑COD、氮和磷等指标,控制系统内循环回流比为1,可得到良好的处理效果.对系统进行物料平衡计算,结果表明,聚磷菌约吸磷0.18 mg P/mg COD,与文献值接近.试验发现,系统中存在着反硝化聚磷菌(DPAOs),其比吸磷速率为13.2 mg P/(g VSS·h),根据缺氧与好氧比吸磷速率之比计算DPAOs约占总PAOs数量的23%.

Influence of Internal Circulation on Nitrogen and Phosphorus Removal in Orbal Oxidation Ditch

The influence of inner circulation on nitrogen and phosphorus removal was investigated using real wastewater in a modified pilot scale Orbal system,in which the volume of main reactor is 460 L.Excellent nutrient removal was achieved.The resistance of the system to ammonia load strike and the efficiency of TN removal was improved with the inner circulation increasing,while the phosphorus removal getting worse. Preferable nutrient removal was achieved when the inner circulation was control at 1.Mass balance in the system showed that about 0.18 rag P/mg COD was taken up by the microorganism,which was compared to literature.Denitrifying phosphate-accumulating organisms,of which the specific phosphorus uptake rate is 13.2 mg P/(g VSS·h),were found to be existing in the system.The ratio of anoxic/aerobic phosphorus uptake rate indicates that the fraction of DNPAOs in total PAPs was 23%.