Bioaccumulation of cadium, copper, zinc, and nickel by weed species from municipal solid waste compost

A field experiment was conducted to evaluate the efficiency of native monocotyledonous weed species for heavy metal phytoextraction from municipal solid waste (MSW) compost. Results showed that total contents of cadium (Cd), copper (Cu), and zinc (Zn) in MSW compost generally exceeded the maximum levels indicated in Chinese regulations, except nickel (Ni). The general trend of metal accumulation in plants was Zn>Cu>Ni>Cd and accumulation differences depended on plant species. Except for Carex tristachya, the Cd, Cu, and Ni contents in above-ground parts of four other species were within the normal values in plants. Most plants accumulated target metals mostly in the roots. With BCF and TF values >1, Carex tristachya displayed some Cd-hyperaccumulative characteristics, being classified as potential species for phytoextraction of Cd from MSW compost. Other species can be considered adequate candidates for metal stabilization and soil conservation.