低负荷人工湿地对城市生活污水处理效果的研究

采用模拟湿地,研究低负荷人工湿地对城市生活污水中化学需氧量(重铬酸钾法测定,CODCr)、总氮(TN)、总磷(TP)、铵态氮(NH4 -N)和硝态氮(NO-x-N)的处理效果,探讨污染负荷对污染物去除效果的影响。结果表明:以黑麦草为湿地植物的人工湿地对城市生活污水有较好的净化效果,其对CODCr、TN、TP、NH4 -N和NOx--N的去除率分别为75.6%、93.2%、95.7%、96.2%和66.5%;污水中65.7%的CODCr、87.2%的TN和95.0%的TP在进水后1 d内被去除,其中基质的物理化学固定作用是污染物快速去除的重要因素;停留5 d以上时可去除湿地中硝化作用累积的少量NOx--N。在一定的污染负荷范围内,CODCr、TN、TP和NH 4-N的去除速率均与其污染负荷呈显著线性正相关。污染负荷是低负荷人工湿地中污染物去除的重要影响因素。

Effect of constructed wetland on treatment of municipal sewage at lower loading rates

Performance and dynamic removal of typical pollutants in municipal sewage treated by 3 simulating constructed wetland cells at lower loading rates were observed,and the impact of pollutant loading rate for pollutants' removal was also investigated.The results indicated that the constructed wetland planted with ryegrass(Lolium multiflorum L.) had good performances for treatment of municipal sewage.The removal efficiencies of CODCr,TN(total nitrogen),TP(total phosphorus),NH 4-N and NO-x-N were 75.6%,93.2%,95.7%,96.2% and 66.5%,respectively.Most of CODCr(65.7%),TN(87.2%) and TP(95.0%) were degraded within one day after sewage affused,and adsorption and immobility of stuffing may be an important precondition for pollutants' rapid removal.Whereas the removal of NO-x-N accumulated by microbial nitrification needed longer than 5 days resident time.The removal loading rates of CODCr,TN,TP and NH 4-N were positively correlated with their pollutant loading rates.The pollutant loading rates had great influence on the removal of typical pollutants in municipal sewage.