Study on removal potential of Cu, Ni, Pb and Zn from four plants under hydroponic conditions

Four plants were selected for formal experiments: Iris sibirica L., Hydrocotyle vulgaris L., Alternanthera philoxeroides (Mart.) Griseb. and Sedum aizoon L. The tolerance, enrichment and migration ability of these four plants for copper, nickel, lead and zinc were investigated. S. aizoon and H. vulgaris were Cu hyperaccumulators, and all the plants were Ni hyperaccumulators. When the copper concentration was 200 mg/L, I. sibirica had the highest removal rate for copper in water (91.44%). The A. philoxeroides removal rate remained above 69% at each Ni concentration, which was much greater than that of the other plants. When the lead concentration was 200 mg/L, S. aizoon had the highest removal rate for lead in water (98.84%). The H. vulgaris and S. aizoon removal rates were stable at the four Zn concentrations, all above 89%. Therefore, these plants can be used in appropriate situations to design ecofriendly restoration of wastewater containing harmful heavy metals.

本研究选取4种供试植物开展正式实验：西伯利亚鸢尾(Iris sibirica L.)、普通天胡荽(Hydrocotyle vulgaris L.)、空心莲子草(Alternanthera philoxeroides (Mart.) Griseb.)与费菜(Sedum aizoon L.)。本研究探究了这4种植物对铜、镍、铅、锌四种重金属的耐受性、富集能力与迁移性能。其中，费菜与普通天胡荽为铜超富集植物，所有供试植物均为镍超富集植物。当水体铜浓度为200 mg/L时，西伯利亚鸢尾对水中铜的去除率最高，达91.44%。空心莲子草在各镍浓度梯度下的去除率均维持在69%以上，远高于其余三种供试植物。当水体铅浓度为200 mg/L时，费菜对水中铅的去除率最高，为98.84%。普通天胡荽与费菜在4种锌浓度梯度下的去除率均保持稳定，均高于89%。据此，可根据实际应用场景选用上述植物，设计构建环保型有害重金属废水生态修复方案。