土著水生植物对页岩气钻井废水中Cu和Pb的去除及富集特征

摘要

为实现页岩气钻井废水绿色环保无害化现场处理,选取页岩气井场附近的土著水生植物凤眼莲(Eichhorniacrassipes)、水花生(Alligator phdoxeroides)、鱼腥草(Herbahouttuyniae)、狐尾草(Alopecuruspratensis)、菖蒲(Acoruscalamus)、雍菜(Swamp mrningglory)为试验植物,考察植物单一养殖与5种植物(凤眼莲、水花生、鱼腥草、狐尾草、菖蒲)组合作用时对页岩气钻井废水中Cu、Pb的去除率及生物富集特征.结果表明:凤眼莲对钻井废水中Cu的去除效率最高,达到83.04％,对Pb的去除效率达到88.89％,根部吸附重金属离子能力较强;鱼腥草对废水中Cu、Pb富集能力较强BCF(富集系数)达400以上,地上转运系数在0.5以上,Cu、Pb主要富集在茎叶;雍菜对页岩气钻井废水的毒性物质较为敏感,不易存活.水生植物组合养殖时,对废水中Cu、Pb的降解速率大于单一养殖,分别达到82.17％、88.03％.试验用土著水生植物对页岩气钻井废水中Cu、Pb的BCF均达到200以上.研究显示,通过土著水生植物对页岩气钻井废水中的Cu、Pb可以进行有效降解.%For further harmless field processing of wastewater from shale gas drilling fluid,the effects of aquatic plants (e.g.,Eichhornia crassipes,Alligator philoxeroides,Herbahouttuyniae,Alopecurus pratensis,Acorus calamus,swamp morning glory and their blends)on the degradation and bioconcentration of Cu/Pb in the wastewater during drilling of shale gas were studied.The results showed that the removal effects of Cu and Pb were 83.04％ and 88.89％ by use of E.crassipes.The bioconcentration factor of Herbahouttuyniae was over 400,and the translocation factor was more than 0.5.In addition,swamp morning glory was sensitive to toxic substances and could hardly survive in the drilling wastewater.The effects of plant blends on Cu and Pb removal,which reached 82.17％ and 88.03％ respectively,was better than single ones,and the bioconcentration factor(BCF) of Cu/Pb by aquatic plants was over 200.The results revealed that Cu and Pb in drilling wastewater of shale gas could be efficiently removed via native aquatic plants.