体积比对分段进水工艺处理低浓度废水性能的影响

采用改良A2/O四点分段进水工艺处理低浓度、低碳氮比城市生活污水.在HRT为8.7 h、SRT为15 d、污泥回流比为75%、进水流量分配比为20∶35∶35∶10、好氧段ρ(DO)为1~1.5 mg/L条件下,通过调整不同的厌氧/缺氧/好氧体积比,分析体积比对污染物去除性能的影响.结果表明:不同的体积比对COD、氨氮的去除基本无影响,但对TN、TP去除影响较大.当厌氧/缺氧/好氧体积比为4∶8∶10时,对污染物去除效果最佳,出水COD、氨氮、总氮、总磷质量浓度分别为28.12、0.58、9.26、0.43 mg/L,进水碳源有效利用率达72.4%.通过逐步减少好氧段体积以提高缺氧段体积的策略,可使进水碳源在各缺氧段或厌氧段被充分利用,同时有利于反硝化除磷菌的富集,DPAOs最高比例为20.9%.

Influence of Volume Ratio on the Modified Four Step-feed Technology to Treat Weak Wastewater

The influence of different volume ratio on pollutants removal was studied. The optimal effluent performance of COD,NH+ 4-N,TN and TP were 28. 12,0. 58,9. 26 and 0. 43 mg / L,respectively,with anaerobic / anoxic / oxic volume ratio of 4∶ 8∶ 10. More than 72% of carbon sources were utilized effectively for phosphorus release and denitrification,and about 12. 6% of TN was removed through simultaneous nitrification and denitrification( SND) in oxic zones. The experimental results also indicated that the volume ratio had no distinct effect on COD and NH+ 4-N removal,but had distinct impact on TN and TP removal. At the same time,with the strategy that reduce the volume of the aerobic zone to improve the anoxic volume, the autotrophic bacteria could take full advantage of more carbon sources for denitrification and phosphorus release in each anoxic or anaerobic zone,and which was also conducive to enrich denitrifying poly-phosphate accumulating organisms( DPAOs). The highest proportion of DPAOs was 20. 9%.