【摘要】 以粉煤灰(F)、河砂(S)、河砂+粉煤灰(S+F)为基质,搭配水芹(Oenanthe javanica)、灯芯草(Juncus effusus)和水葫芦(Eichhornia crassipes),研究人工湿地对废水中Cd的净化效果。结果表明,3种基质对Cd均有明显的去除效果。其中,F基质去除效果最好,但出水pH和电导率较高,且水芹和水葫芦相对电导率(REC)和丙二醛(MDA)较高,表明植物生长受到影响。S基质对Cd去除率最低,但植物生长状态良好。S+F基质发生协同作用,有利于植物生长,去除Cd效果也较好,评估为最佳人工湿地基质。人工湿地中不同基质各层全量Cd、有效态Cd分布情况均为上层>中层>下层。更多还原

【Abstract】 Fly ash(F),river sand(S),river sand-fly ash mixture(S+F)used as substrates,with Oenanthe javanica,Juncus effuses and Eichhornia crassipes used as wetlands plants,the purification effects of constructed wetlands on Cd were studied.The results showed that 3 kinds of substrates had significant removal effect on Cd,and the removal of F was the best,however,its pH and conductivity of effluent were too high.Relative electric conductivity(REC)and malondialdehyde(MDA)contents of Oenanthe javanica and Eichhornia crassipes were high,inhibiting the growth of plants.The removal efficiency of Cd by S was lowest,but plants grew well.By contrast,the synergistic effect of S+F was beneficial to plant growth,and the removal efficiency of Cd was also good.Therefore,S+F was considered as the best substrate of constructed wetland.The distribution of total Cd and available Cd in different layers of substrates of the constructed wetlands were upper layer>middle layer>lower layer.更多还原