Bioremediation of dumpsite leachates and heavy metals contaminated groundwater using locally sourced organic wastes as reactive media

Abstract

This study examines the problems of dumpsites leachates and contamination of the surrounding groundwater sources in three States of the Southeast Nigeria, and possible ways of solving them. The leachates and groundwater were characterised from the study area and the samples showed heavy metals concentrations beyond WHO permissible standard. The method employed permeable reactive barrier (PRB) system to address the problem, using four locally sourced biomaterials wastes (wood shavings (WS), sugarcane bargasse (SB), rice husk (RH) and palm kernel shell PKS) as treatment media to intercept the leachate as treatment barrier for heavy metals contaminants before percolating into the groundwater as treated water. The contaminants samples (Co, As, Pb and Cd) were grouped into low (9.87 ppm – 2.77 ppm) and high concentrations (85.41 ppm – 50.32 ppm) Results showed removal efficiency of 100%, 99.49%. 99.78% and 99.96% on low concentrations and 75.84%, 63.88%, 71.01% and 67.50 % for high concentrations on WS, SB, RS and PKS. In all, wood shaving proved to be the most effective materials for treatment of heavy metals contaminated waters. This study provided useful background information for use of locally sourced and cheap biomaterials as permeable reactive barrier for wastewater treatment.