固体碳源及生物强化CAST工艺处理低C/N生活污水的效果

目的]研究固体碳源及生物强化CAST工艺处理低C/N生活污水的效果。方法]设2组CASS反应器,试验组投加玉米芯填料与生物强化菌剂,对照组不投加玉米芯和生物强化菌剂。试验运行阶段对进出水进行氨氮(NH_4~+-N)、总氮(TN)、化学需氧量(COD)等指标进行持续监测。试验后期,取挂膜填料与2反应器中的污泥进行电镜分析。结果]从池塘底泥中筛选出3株具有高效反硝化作用的好氧反硝化菌,分别为假单胞菌(Pseudomonas sp.)、施氏假单胞菌(Pseudomonas stutzeri)、铜绿假单胞菌(Pseudomonas aeruginosa),对硝酸盐和亚硝酸盐去除率均在85%以上。电镜分析表明,固体碳源表面结构粗糙,孔隙内及表面附着大量的杆菌、球菌及丝状菌等微生物,生物量有明显的提高。试验组出水COD浓度维持在40.00 mg/L左右,NH_4~+-N的平均出水浓度由11.35 mg/L降至4.58 mg/L;平均出水TN浓度由24.74 mg/L降至12.11 mg/L。反应器运行20 d后,试验组污泥结构相对于对照组更加紧密。结论]固体碳源及生物强化CAST工艺处理低C/N生活污水可行性强,发展前景广阔。

Effect of Solid Carbon Source and Biofortification CAST Process on Low C/N Domestic Sewage Wastewater

Objective]To study the effect of solid carbon source and biofortification on enhance the nitrogen removal performance of low C/N ratio domestic wastewater in CAST process.Method]2 sets of CASS reactor were set up,the test group was filled with corncob stuffing and bioaugmentation agent,and the control group did not add corncob and bioaugmentation bacteria.During the test stage,NH4+-N,TN and COD were monitored continuously.In the later stage of test,the sludge in the two reactor and the sludge in the reactor were analyzed by electron microscope.Result]Three aerobic denitrifying bacteria with high denitrification were screened out from the pond sediment.The three strains were identified as Pseudomonas sp.,Pseudomonas stutzeri and Pseudomonas aeruginosa.After testing,the removal rate of nitrate and nitrite was more than 85% in these 3 strains.Electron microscope analysis of the solid carbon source in the later stage of the experiment showed that the surface structure was rough,and a large number of bacteria,such as bacillus,coccus and filamentous bacteria were attached to the surface.The effluent COD remained at about 40.00 mg/L,the average effluent concentration of NH4+-N from 11.35 mg/L to 4.58 mg/L.The average concentration of effluent TN decreased from 24.74 mg/L to 12.11 mg/L.After 20 days of reactor operation,the sludge structure of the experimental group was closer to the control group.Conclusion]Solid carbon source and biological strengthening treatment of CAST process are feasible for low C/N domestic sewage and have broad prospects for development.