Extraction of Heavy Metals from Soil Affected by Landfill Leachate through Constructed Wetlands: A Phytoremediation Approach to Rejuvenating the Contaminated Environment

Abstract

Water is one of the most essential elements of life. The water shortage is becoming a lurid issue in many regions, with over a billion people without passable water for drinking purposes. The leachate from landfill sites is a major problem and poses a threat to aquatic ecosystems and public health. To overcome this situation, either to remove contaminants or to reduce the amount of contamination, constructed wetlands using phytoremediation can be considered the best solution. This green low-cost technology uses plants to remove heavy metals from soil and water. The objective of this report is to study the removal of specific heavy metals such as Zinc (Zn), Nickel (Ni), Chromium (Cr), Cadmium (Cd), Iron (Fe) and Lead (Pb) from landfill leachate by using two laboratory scaled wetlands. These wetlands were filled with soil and planted with Typha Latifolia. One system was operated without recirculation and the other with effluent recirculation with an interval of one day. The influent and effluent physicochemical parameters were analyzed after 30 days and the concentrations of the heavy metals were observed. The wide variation is seen in the case of Nickel, Lead, Chromium, Cadmium, Zinc and Iron. The percentage of removal with recirculation and without recirculation is 100% for Cadmium and Iron, in the case of Nickel, Lead, Chromium and Zinc the percentage difference between recirculation and without recirculation was found to be 1.6, 2.4, 0, 0. Since the removal efficiency for Cadmium and Iron is predominant this study indicates that this technology gives good removal of heavy metals and has a scope for its effective analysis since it has low working and conservation costs; it is comparatively a step toward a sustainable economy.