Evaluation of the phytoremediation potential of selected hydrophytes grown in wastewater. A case study in Sheikhupura, Pakistan

Abstract

Water pollution is a major environmental issue and human health risk worldwide.  With rapid industrialization and economic growth, water bodies are contaminated at large scale. In the current study the concentration of four heavy metals (HMs)  cadmium (Cd), copper (Cu), nickel (Ni), and manganese (Mn) was measured in water, sediment, and hydrophytes (Eichhornia Crassipes, Pistia stratiotes and Lemna minor) samples collected from wastewater stream in Sheikhupura, Punjab, Pakistan. The results revealed that the concentrations of Cd (0.23 mg L^-1), Cu (5.00 mg L^-1), Mn (6.00 mg L^-1), and Ni (3.00 mg L^-1) in water samples were  above the permissible limits (APL) set by the World Health Organization (WHO). However, the concentration of Cd, Cu, Mn, and Ni in sediment samples was found to be below the maximum permissible limits (BMPL) set by  WHO. The WHO permissible limits for Cd, Cu, Mn, and Ni in water is 0.01, 0.02, 0.20, and 1.40 mg L^-1 respectively while in sediments is 3.00, 100, 2000, and 50 mg kg^-1 respectively.  In addition, Mn concentration was highest among all the tested hydrophytes, water, and sediment samples. HMs contents were higher in hydrophytes as compared to water and sediment samples. In addition, all three hydrophytes were found to absorb HMs from wastewater with bioaccumulation factor ranging from 2.52 to 216. Current data revealed that Pistia stratiotes have greater potential to absorb HMs from water as compared to Eichhornia Crassipes, and Lemna minor