低温城市生活污水再生全流程中A/O高效除磷研究

STUDY ON HIGH-EFFICIENCY PHOSPHORUS REMOVAL OF A/O SYSTEM IN INTEGRATED RECLAMATION FOR MUNICIPAL SEWAGE AT LOW TEMPERATURE

研究了低温条件下污水再生全流程中A/O生物除磷系统的稳定运行。结果表明,在低温条件下(10～14℃),不同污泥负荷对出水效果影响显著,在系统NSCOD(COD污泥负荷)为0.6 kg.kg-1.d-1,DO质量浓度为1～2 mg.L-1时,系统仍有较好的处理效果,出水ρ(TP)<0.7 mg.L-1,除磷率达到84%～96%,出水COD<60 mg.L-1,COD去除率达到80%～88%;试验发现A/O系统进水碱度、VFA充足,无需外投加碱度和VFA即可获得较好的除磷效果;pH、ORP能够反映聚磷菌的活性,pH是聚磷菌活性的表征,pH较高时磷的去除效果显著,聚磷菌活性高;随着磷的去除效果不断增强,聚磷菌的活性逐渐升高,厌氧池内ORP值降低;A/O除磷系统可以实现对污水中氮素最大限度的保留,实现亚氮、硝氮的最小积累,为后续的自养脱氮提供稳定适宜的进水。

The stable operation of A/O biological phosphorus removal process under low temperature based on the concept of Integrated reclamation flow for municipal sewage was analyzed. The test showed that： Under low temperature conditions （10-14℃）, the variation in influent loads had significant influence on effluent equality, moreover, with the NscoD and dissolved oxygen（DO） at the level of 0.6 kg. kg-1. d-1 and 1-2 mg L -1respectively, a good effiuent quality was obtained. The effiuent concentration ofTP was under 0.7 mg,L-1, the removal rate ofTP reached 84%-96%.The effiuent concentration of COD was under 60 mg .L-1, the removal rate of COD reached 80%-88%.There was enough alkalinity and VFA in influent to achieve better phosphorus removal efficiency without external adding, pH and ORP had significant relation on the phosphorus removal efficiency. The value of pH reflected the activity of PAO, It can achieve better efficiency at the high level of pH, the activity of PAO was at the high level; With activity of PAO increased, the ORP decreased. With minor nitrogen loss and little nitrite and nitrate accumulation, A/O system had little effect on nitrogen, which was important to offer stable influent for further nitrogen removal.