延长缺氧水力停留时间对A-AAO工艺氮磷去除影响的研究

相比传统厌氧-缺氧-好氧(简称AAO)脱氮除磷工艺,改良AAO工艺(定义为A-AAO)增加了回流污泥的硝酸盐反硝化区并对进水多点分配,氮磷去除能力得到显著提高。为进一步优化A-AAO的除污染能力,本研究以A-AAO工艺后2部分缺氧和好氧段(AO段)为对象,研究AO段水力停留时间改变对A-AAO工艺脱氮除磷的影响。试验采用两套小试规模A-AAO工艺(定义为1#和2#反应器)开展研究,1#反应器缺氧段及好氧段停留时间分别为5.5 h和10 h,2#反应器缺氧段及好氧段停留时间分别为2.5 h和13 h。研究结果表明:总停留时间不变,缩短好氧停留时间而延长缺氧停留时间有助于氮磷的去除。1#和2#反应器总氮和总磷平均去除率分别为61.36%、57.08%和85.72%、82.0%。

Effects of Extending Hydraulic Retention Time on Nitrogen and Phosphorus Removal with A-AAO Process

Compared with the traditional anaerobic-anoxic-aerobic(AAO)denitrification and phosphorus removal process, the modified A-AAO process(defined as A - AAO)increases nitrate denitrifying zone of reflux sludge and multipoint distribu-tion,which improves denitrification and phosphorus removal significantly. In order to optimize pollution removal of the A-AAO process further,the hydraulic retention time of the anoxic and aerobic zone of the Modified A-AAO has been studied as the ob-jects of this study. Two lab-scale Modified A-AAO processes were operated. The anoxic and aerobic retention time of 1#reac-tor are 5.5h and 10h respectively,and the two parameters of 2#reactor are 2.5h and 13h respectively. The research results show that to shorten the aerobic hydraulic retention time and to prolong the anoxic hydraulic retention time is beneficial to nitrogen and phosphorus removal. The mean total nitrogen removal and the mean total phosphorus removal of 1#and 2#reactor were 61.36%, 57.08% and 85.72%,82.0%,respectively.