循环比对氧化沟脱氮除磷效果及磷转化途径的影响

在改良型氧化沟工艺的循环廊道内增设缓流板,以此改变循环廊道过流断面面积,进而调控循环比(循环廊道断面通过的循环流量和进水流量的比值)。利用胞内、胞外聚合物的分析及物料平衡的方法,研究了增设缓流板、调控循环比前后系统同步脱氮除磷效果和磷转化途径的变化及聚磷菌种含量的差别。结果表明,增设缓流板,循环比为27时,COD、NH+4、TN和TP的平均去除率分别为93.3%、87.1%、78.1%和96.0%,反硝化聚磷菌占总聚磷菌的比例为46.1%;而不设缓流板,循环比为241时,COD、NH+4、TN和TP的平均去除率分别为91.2%、82.7%、67.2%和86.4%,反硝化聚磷菌占总聚磷菌的比例为17.54%。综上可知,增设缓流板控制循环比,有助于提高反硝化聚磷菌的富集,有助于提高反硝化吸磷量,同时有助于提高氧化沟工艺的同步脱氮除磷效果。

Effect of recirculation ratio on nutrient removal and phosphorus transformation in oxidation ditch

The recirculation ratio (namely the ratio of circulation flow to influent flow in circulation compartment section) was regulated by installation of flashboard in the circulation compartment section of modified oxidation ditch, and the flashboard was used to change the flow section area. The differences of the nutrient removal rates, phosphorus transformation and the phosphate-accumulating organisms' content were researched by measuring intracellular and extracellular polymers and mass balance method before and after flashboard installation and recirculation ratio regulation. The results showed that the average removal rates of COD, NH₄⁺, TN, TP were 93.3%, 87.1%, 78.1% and 96.0%, respectively, and the proportion of denitrifying phosphate-removal bacteria to total phosphorus accumulating organisms was 46.1%, when the recirculation ratio was 27 with the flashboard. However, the average removal rates of COD, NH₄⁺, TN, TP were 91.2%, 82.7%, 67.2% and 86.4%, respectively, and the proportion of denitrifying phosphate-removal bacteria to total phosphorus accumulating organisms was 17.54%, When the recirculation ratio was 241without the flashboard. So, regulating recirculation ratio by setting flashboard was useful for enrichment of denitrifying phosphate-removal bacteria,useful for increment of denitrifying phosphate-removal rates and useful for improving the nutrient removal rates in oxidation ditch.