LAUSR

When the high-density sludge (HDS) process is adopted to treat copper mine wastewater, a large amount of sediment is generated. Sediment can be used as the guest soil after fertilization and restoration, which plays a role in the ecological reclamation of mines. To explore the effect of different phytoremediation approaches on the physicochemical properties of HDS sediment, the untreated sediment was employed as the control group, whereas sediments repaired by six kinds of plants, including slash pine (Pinus elliottii Engelmann), Chinese white poplar (Populus tomentosa Carr.), black locust (Robinia pseudoacacia), Photinia × fraseri, Ligustrum quihoui, and Ligustrum japonicum Thunb, were selected as the test groups. Then, the water content, pH, organic matter, total nitrogen, total phosphorus, total potassium, available phosphorus, and available potassium contents in the sediment samples were analyzed. The results showed that, among the six experimental groups, the L. japonicum group achieved the most significant effects on sediment pH and total nitrogen content. Meanwhile, the slash pine group improved the sediment organic matter content, available phosphorus content, and available potassium content to the greatest extent. The black locust group had the most significant effects on the sediment total phosphorus content. As discovered from the grey correlation analysis results, slash pine has the best comprehensive effect of improving the physicochemical properties of sediment among the six plants, followed by black locust, Photinia × fraseri, Chinese white poplar, Ligustrum quihoui, and Ligustrum japonicum Thunb.