改良氧化沟工艺处理城市污水除磷试验研究

Experimental research on the modified oxidation ditch process for the removal of phosphorus from urban sewage

采用水解酸化-厌氧-改良氧化沟多点强化氧化沟除磷工艺,通过对前置水解酸化反应器、氧化沟水力停留时间及二沉池污泥回流比的调控,对混合型城市污水进行除磷研究。结果表明,当进水COD、TP平均分别约为557、5.9 mg/L,总水力停留时间为17.5 h,污泥回流比为1,平均DO为2-4 mg/L,无外加碳源时,经上述工艺处理后,出水COD、TP平均分别为54.9、0.9 mg/L,COD、TP平均去除率可分别达到90.1%、86.4%。水解酸化-厌氧-改良氧化沟工艺对混合型城市污水的除磷效果良好、稳定可靠。

A pilot scale hydrolysis/acidification-anaerobism-modified oxidation ditch process for the removal of phosphorus from mixed urban sewage has been studied,through the regulation and control of HRT of pre-hydrolysis/acidification reactor,HRT of oxidation ditch and sludge reflux ratio of secondary sedimentation tank. The results show that under the following conditions：the influent average concentrations of COD is 557 mg/L,and TP 5.9 mg/L,total HRT 17.5 h,sludge reflux ratio=1, averge DO 2-4 mg/L,and without extra carbon source,the average concentrations of effluent COD and TP are 54.9 mg/L and 0.9 mg/L,respectively,the average removing rates of COD and TP are 90.1% and 86.4%,respectively. It indicates that the hydrolysis/acidification-anaerobism-modified oxidation ditch process has good phosphorus removing effect on mixed urban sewage,being stable and realiable.