A Study on Influence of pH and Organic Chemical on the Retention Capacity of Red Earth

Abstract

Improper dumping practices may consume more land and contaminate the surrounding environment. There is a necessity to design a proper sanitary landfill in order to control the environmental effects. If a locally available soil meets the criteria of landfill material, the locally available material can be used to construct the compacted clay liner (CCL). This paper presents the feasibility study on the utilization of the locally available red earth as a landfill liner based on its contaminant sorption capacity. The potential for retention of lead (Pb²⁺) by red earth from the Warangal city in India is examined. Lead solution of varying initial concentrations and pH values were used for the analysis. In addition, an attempt is made to observe the influence of organic chemical (EDTA) on the retention capacity of red earth. Batch sorption tests were conducted for a single salt solution with and without organic chemical, and results were presented. From this study, it is revealed that with an increase in the initial concentration of the lead solution from 10 to 30 mg/L, the percentage removal was decreasing. Whereas with an increase in pH from 2 to 7, the maximum increase in percentage removal was observed as 23% at maximum initial concentration (30 mg/L). With the presence of organic chemical, at neutral pH value, the decrease in the sorption capacity of soil was at least 36% at maximum initial concentration (30 mg/L).