Solar-powered electrocoagulation for the removal of atrazine with and without microplastics†

Abstract

Emerging contaminants, particularly pesticides and microplastics (MPs), pose a substantial risk to both human beings and ecosystems. While atrazine (ATZ) and MPs have been found to coexist in environmental media, limited studies have investigated their combined interaction and removal. Moreover, the application of electrocoagulation (EC) for simultaneously addressing these contaminants remains unexplored. This study was conducted with ATZ concentration (3–20 mg L⁻¹), where the effects of electrode materials, current density, pH, and supporting electrolyte concentration were analysed. In general, the removal kinetics for ATZ were best described by the first-order model for both Al and Cu electrodes. The ATZ removal efficiencies were evaluated in real water matrices and found to be 79.85 ± 1.03, 75.92 ± 1.25, 70.58 ± 1.49, 68.09 ± 1.10, and 64.42 ± 2.25% in distilled deionized water, ground, lake, river, and wastewater, respectively using Cu electrodes. Removal of ATZ was higher (84.52 ± 1.04%) in the presence of microplastics as they served as coagulant aids. The effect of polarity reversal was examined to reduce anode fouling during electrolysis and longer intervals of 10 min yielded higher removal efficiencies than intervals of 5 min or no polarity reversal. This research found that EC is an economical and sustainable solution to pesticide and MP pollution in aquatic ecosystems. This study advances Sustainable Development Goals (SDG) by enhancing clean water access (SDG 6), promoting health through pollutant removal (SDG 3), and using solar power as an energy source to run the reactor is aligned with SDG 7.