重金属镉胁迫下好氧颗粒污泥脱氮除磷特征分析

为探究重金属镉(Cd)胁迫下,好氧颗粒污泥培养及脱氮除磷的特征,以絮状物质为探究对象,采用摇床震荡并添加不同剂量Cd胁迫下好氧颗粒污泥的形成及脱氮除磷特征。结果表明在低浓度Cd(0.1mg/L和0.5 mg/L)时,颗粒污泥浓度增加,污泥沉降性加强,而当Cd质量浓度为3.0 mg/L,颗粒污泥稳定时期混合液悬浮固体(MLSS)浓度下降至2.16~2.19 g/L,污泥体积指数(SVI)升高至124.6~129.5 mL/g。进水Cd影响颗粒污泥脱氮除磷,0.1 mg/L和0.5 mg/L Cd提高总氮(TN)去除效率至81.5%~82.3%和83.4%~83.6%,而当3.0 mg/L Cd降低TN去除效率至54.9%~55.6%。低浓度Cd对总磷(TP)去除影响不明显,而高浓度Cd抑制TP去除。元素分析表明Cd浓度降低颗粒污泥表面Na与Ca的含量。

Characteristics of Nitrogen and Phosphorus Removal by Aerobic Granular Sludge under HeavyMetal Cd Stress

In order to investigate the characteristics of aerobic granular sludge culture and nitrogen and phosphorus removal under the stress of heavy metal cadmium(Cd),the floccules were taken as the research object,and the formation of aerobic granular sludge and nitrogen and phosphorus removal characteristics were studied in shaking tablebyadding different doses of Cd.The results showed that,at low concentrations of Cd(0.1 mg/L and 0.5 mg/L),the concentration of granular sludge increased and the sludge sedimentation were enhanced,while when the concentration of Cd was 3.0 mg/L,the mixed liquid suspended solids(MLSS)concentration during the period of stable granular sludge decreased to 2.16~2.19 g/L,the sludge volume index(SVI)increased to 124.6~129.5 mL/g.Influent Cd affectednitrogen and phosphorus removal of granular sludge,0.1 mg/L and 0.5 mg/L Cd increased the total nitrogen(TN)removal rate to 81.5%~82.3%and 83.4%~83.6%,while 3.0 mg/L Cd reduced TN removal efficiency to 54.9%~55.6%.Low concentration of Cd had no significant effect on total phosphorus removal,while high concentration of Cd inhibited TP removal.Elemental analysis showed that Cd concentration reduced Na and Ca content on granular sludge surface.