Optimizing solar powered electrokinetic remediation of chromium contaminated groundwater: One step closer to a sustainable solution

Abstract

Electrokinetic remediation (EKR) presents a promising solution for addressing soil and groundwater contamination challenges. However, practical viability is hindered by significant energy consumption and related expenses, necessitating a comprehensive sustainability approach beyond solely adopting renewable energy and low-carbon sources. This study aims to merge innovative solar-powered systems with a risk-based evaluation strategy for tackling chromium-contaminated groundwater, providing valuable insights into EKR economically viable and applicable approaches. Through the integration of environmental and electrical engineering expertise, this study introduces the Continuous Solar-powered Electrokinetic Remediation (CSER) system and risk-based energy efficiency (REF) evaluation approach, addressing intermittency issues while optimizing energy generation and minimizing costs. Experimental results demonstrate removal efficiencies ranging from 29.85% to 84.26%, highlighting the impact of intermittent current, voltage boosters, and electrolyte selection on risk reduction and energy consumption. While intermittent current intensifies the focusing phenomenon and reduces contaminant migration, it may offer promising results in specific cases, such as observed in the EK2 experiment. Conversely, the EK3 results reveal that the integration of conventional solar power with a voltage booster may enhance removal rates but often leads to unfavorable outcomes in risk reduction considering related higher energy consumption. However, CSER, with its utilization of constant current, proves more efficient in power generation, risk reduction, and energy usage compared to other systems. Integration of such a system with cost-effective and environmentally friendly chemical agents could significantly increase the REF index while minimizing related costs, thereby shifting EKR remediation techniques towards sustainable solutions for contaminated groundwater worldwide.