Study On The Tolerance And Enrichment Characteristics Of Vetiveria Zizanioides And

A large number of wastewater containing uranium was generated by uraniummining and milling, which brought the long-term potential threat to waterenvironment and human. In this study, vetiveria zizanioides and acorus calamus wereused as objects, and the effect of different concentrations of uranium (0,0.1,1,5,10and20mg·L-1) on biochemical responses and of two plants were investigated with themethod of the hydroponic experiment, which includes photosynthetic pigment,soluble protein and MDA contents, antioxidant enzyme activities, and mercaptocompound contents. And the uranium accumulation potential of two plants wasstudied. The experiment results can provide a theoretical basis and reference data forphytoremediation of uranium-contaminated wastewater. The main results are asfollows：The photosynthetic pigment and soluble protein contents in two plants increasedat first and decreased subsequently. The photosynthetic pigment and soluble proteincontents in vetiveria zizanioides and acorus calamus reached its highest value at0.1mg·L-1and5mg·L-1of U, respectively. Uranium stress had no effect on thephotosynthetic pigments of vetiveria zizanioides during the whole treatment, but theeffect on acorus calamus reached significantly. The effect on two plants by U reachedsignificantly.The CAT and POD activities in vetiver leaves and roots were increasedgradually under different uranium concentration, but SOD activity decreasedgradually. The SOD, CAT and POD activities in acorus calamus increased at first anddecreased subsequently. And the CAT and POD activities reached its highest valuewhen uranium stress concentration was1mg·L-1, but SOD activity was at0.1mg·L-1of uranium stress. The MDA contents in two plants increased gradually and thehighest content in two plants reached138%and286%of control, respectively. ThePCs content had no significant changes in roots of vetiveria zizanioides during thewhole treatment, but the PCs contents in leaves increased gradually and the effectreached significantly. The PCs contents in acorus calamus increased gradually. Whenthe uranium concentration was20mg·L-1, the highest content in leaves and roots reached2.04and3.00times, respectively.The enrichment of uranium by vetiveria zizanioides and acorus calamusincreased with uranium concentration increasing. The uranium enrichment capacityby acorus calamus was higher than vetiveria zizanioides, and the uranium enrichmentcapability in root was stronger than leaves. When uranium stress concentration was20mg·L-1, the maximum enrichment of uranium in roots of vetiveria zizanioides andacorus calamus was1023.5mg·kg-1and2802.6mg·kg-1, respectively. And themaximum enrichment of uranium in leaves was63.9mg·kg-1and105.1mg·kg-1,respectively.