人工湿地对猪场废水有机物处理效果的研究

分别以香根草 (Vetiveriazizanioides)和风车草 (Cyperusalternifolius)为植被 ,按 1.0m× 0 .5m×0 .8m建立人工湿地 ,通过 4季测试 ,研究其对猪场废水有机物的净化功能及其随季节、进水浓度及水力停留时间变化的规律 .结果表明 ,4个季节香根草或风车草人工湿地对COD和BOD有较稳定的去除效果 ,两湿地抗有机负荷冲击能力强 .在春季 ,停留时间 1～ 2d ,COD和BOD去除率分别为 70 %和 80 %;在夏季 ,进水COD高达 10 0 0～ 140 0mg·L-1情况下 ,COD去除率接近 90 %;在秋季 ,停留时间 1～ 2d ,COD和BOD去除率分别为 5 0 %～ 6 0 %和 5 0 %;在冬季 ,进水COD达 10 0 3mg·L-1情况下 ,COD去除率在 70 %以上 .COD、BOD和SS的去除率在两湿地间没有显著差异 .人工湿地污染物 (Y)随水力停留时间 (t)延长的降解遵从指数方程规律Yt=Y0 ·e( -kt) .在相同停留时间时 ,随进水污染物浓度 (x)提高的出水污染物浓度 (y)的回归关系遵从直线方程规律 y =a+bx .

Treatment effect of constructed wetlands on organic matter in wastewater from pig farm.

Using plant species Vetiveria zizanioides and Cyperus alternifolius respectively, two constructed wetlands (CWS) with size of 1.0 m x 0.5 m x 0.8 m were established. The purifying function and its change pattern with season, influent concentration and hydraulic retention time (HRT) of the constructed wetlands on the organic matters in wastewater from a pig farm were studied throughout four seasons in the year. The results showed that the two CWS had very stable effects on the removal of COD and BOD, while the organic matters in wastewater changed. The removal rate of COD and BOD was 70% and 80% respectively by HRT 1-2 d in spring. The removal rate of COD reached 90% with the influent of COD 1000-1400 mg.L-1 in summer. The removal rate of COD and BOD was 50-60% and 50% respectively by HRT 1-2 d in autumn. The removal rate of COD reached 70% with the influent of COD 1003 mg.L-1 in winter. There was no significant difference between two CWS in the removal of COD, BOD and SS. The rule of contaminants decreased with the HRT in CWS followed exponential function: Yt = Y0.exp(-kt). The relation between the concentration of contaminants in influent (x) and outflow (y) at the same HRT followed linear relation: y = a + bx.