Environment-friendly catholytes in electrokinetic remediation of heavy metal-contaminated loamy soil: Towards sustainable practice

Soil contaminated with heavy metals (HM) has emerged as a serious global concern. This HM can migrate within the soil and leach into ground and surface water bodies, thus can easily enter the food chain. Hence, development of efficient and cost-effective remediation technique is required. Electrokinetic remediation (EKR) is one such method that can effectively remove various pollutants from diverse wastes and soil medium. In this study, an attempt was made to investigate and remediate multiple HM, such as aluminium (Al), chromium (Cr), copper (Cu), iron (Fe), and manganese (Mn), from highly polluted loamy soil in Tamil Nadu, India. Experimental studies for a duration of 10 days using five distinct catholytes and graphite plate electrodes were conducted. Constant voltage gradient of 2 V/cm was supplied through the electrodes. The study underscores the critical role played by different catholytes adopted in EKR technique for the pollutant extraction. Thus, offering a new approach for treating industrially contaminated loamy soils. The results depict that potassium chloride (KCl) was most effective for extracting Cr (28.1%), while hydrogen peroxide (H 2 O 2 ) worked best for removing Cu (29.35%), Fe (61.4%), Mn (29.5%), and Al (35%) from the soil.