Application of peanut shell ash in geosynthetic clay liners to reduce the Zinc contamination in leachate

Abstract

Human health is seriously harmed by heavy metal contamination. Municipal solid waste disposal facilities are one of the most preferred options that contaminate the land and the groundwater. The liquid produced by the anaerobic oxidation of solid waste in landfills is known as leachate. The leachate contains organic, inorganic, and heavy metals depending upon the type of waste. The main issue in developing nations is the pollution of ground and surface water caused by the generation of leachate. Most heavy metals are carcinogenic in nature and Zinc (Zn) is one of the heavy metals present in the leachate. Kanpur (Uttar Pradesh, India) is a highly polluted city with 1500 Metric tons of waste generated per day. A leachate sample was collected for the study area and its Physico-chemical composition was analyzed. The concentration of Zn was found as 11.47 mg/l in the leachate sample which is more than two times the permissible limit of 5.0 mg/l. The objective of this study is to reduce the Zn concentration of leachate samples after passing through a modified Geosynthetic Clay Liner (GCL). The modified geosynthetic clay liner was developed by adding different proportions (0%, 5%, 10%, 15%, 20%, 25%, and 30%) of Peanut Shell Ash (PSA) with encapsulated Sodium Bentonite (Na-B) in commercial GCL. The efficiency of Zn removal from wastewater using peanut shells has been evaluated. In this study, it has attempted to find the best proportion of Na-B and PSA as encapsulated material of GCL to reduce the concentration of Zn.