4种植物组合对富营养化和重金属复合污染水体的净化效果

PURIFICATION EFFECT OF FOUR PLANT COMBINATIONS ON COMBINED WATER POLLUTION OF EUTROPHICATION AND HEAVY METALS

选取华中地区常见的4种植物多花黑麦草(Lolium multifolorum)、狐尾草(Alopecurus pratensis L.)、蜈蚣草(Pteris vittata L.)和石菖蒲(Acorus gramineus)为研究对象,通过室内静态水培实验研究了4种植物组合对富营养化和重金属复合污染水体的去除效果。研究发现:4种植物组合对不同浓度梯度的富营养化和重金属复合污染水体中的TN、TP、Cd和Pb均表现出良好的去除效果,不同植物组合对各类污染物的去除效果有所差异。经过30 d修复后,各植物组合对低浓度污水中TN、TP、Cd和Pb去除率平均值分别为88.68%~93.66%、64.00%~83.02%、83.84%~93.62%和95.07%~98.02%;对高浓度污水中TN、TP、Cd和Pb去除率平均值分别为94.49%~97.11%、92.85%~94.15%、63.01%~81.42%和88.56%~91.64%;去除率最高的是多花黑麦草与石菖蒲间作。4种植物对Cd和Pb的富集系数均>1,均具有良好的重金属富集能力。低浓度污水中各植物对Cd和Pb的富集能力明显高于高浓度污水,且同一植物对Pb的富集能力明显强于Cd。

In this study,four kinds of native plants in central China including Lolium multifolorum,Alopecurus pratensis L..,Pteris vittata L.,and Acorus gramineus were selected as research objects.Laboratory hydroponic experiments were conducted to study the purification effect of the combined water pollution of eutrophication and heavy metals.The result showed that all the four plant combinations had good removal efcts on TN,TP,Cd and Pb in combined water pollution of eutrophication and heavy metal under different concentration gradients,and different plant combinations presented different removal effects.After 30 days of remediation,the average removal rates of the plant combinations in low concentration sewage for TN,TP,Cd and Pb were 88.68%~93.66%,64.00%~83.02%,83.84%~93.62%and 95.07%~98.02%,respectively.And the average removal rates in high concentration sewage were 94.49%~97.11%to TN,92.85%~94.15%to TP,63.01%~81.42%to Cd,and 88.56%~91.64%to Pb.The intereropping of Lolium multifolorum and Acorus gramineus had the best treatment performance.The bioconcentration factor of four kinds of plants on Cd and Pb was greater than 1,which meant a strong accumulation ability of plants on heavy metals.The accumulation ability of plants on Cd and Pb in low concentration sewage was far greater than those in high concentration sewage.The enrichment ability of Pb was stronger than Cd for the same plant,significantly.