Experimental study on different phytoremediation of heavy metal pollution in HDS sediment of copper mines

HDS sediment is a type of solid waste produced when the high-concentration mud method (HDS) is adopted to treat acid wastewater from copper mines. It can rationally utilize sediment resources by using phytoremediation, which plays a role in the ecological restoration of mines.

To reveal the effect of different phytoremediation on the heavy metal, enrichment capacity and microbial diversity of the HDS sediments of copper mines, in this experiment, the HDS sediments of a copper mine without phytoremediation were selected as the control group, while the sediments of black locust (Robinia pseudoacacia), slash pine (Pinus elliottii Engelmann) and Chinese white poplar (Populus tomentosa Carr.) were used as test groups to analyze the physical and chemical properties, heavy metal pollution and bioaccumulation capacity of HDS sediments under three phytoremediation.

The results show that different phytoremediation can reduce the sediment's conductivity and adjust the sediment’s pH value to the range suitable for plant growth. The BCF_Shoot and BTF values of Chinese white poplar to Cd and Zn and slash pine to Pb were both greater than 1.

As discovered from the bioconcentration coefficient and biotransport coefficient results, Chinese white poplar is a Cd-enriched and Zn-enriched plant, while slash pine is a Pb-enriched plant.