INVESTIGATION AND OPTIMIZATION OF AN ELECTROCOAGULATION TREATMENT PROCESS FOR HYDROPONIC WASTEWATER SOLUTION: PROCESS PERFORMANCE AND KINETIC STUDY

Abstract

The increasing adoption of hydroponic farming has led to the generation of nutrient-rich and metal-laden hydroponic wastewater solution (HWS), which poses significant environmental risks if not properly treated. Given HWS's nutrient-rich and metal-laden profile, untreated disposal risks environmental issues like eutrophication, soil salinization, and ground water contamination. Effectively treating HWS is therefore crucial for preventing environmental degradation, protecting aquatic ecosystems, and ensuring sustainable agricultural practices. This study evaluates the effectiveness of electrocoagulation (EC) for treating HWS, focusing on optimizing conditions to improve contaminant removal, energy efficiency, and feasibility for hydroponic reuse. Results demonstrated near-complete removal for key contaminants under specific conditions: phosphorus (P) and magnesium (Mg) achieved >95% removal at pH 7 and 4.5 mA/cm2, while potassium (K) removal exceeded 99% at pH 4 under the same current density. Total nitrogen (TN) reached a maximum reduction of 91% at pH 10 within 10 minutes. Turbidity reduction reached 94% at higher current densities, showcasing EC's capability to clarify wastewater. Conductivity reduction was also significant, aligning with effective ionic removal. Kinetic studies indicated first-order kinetics for Mg and TN and pseudo-first-order kinetics for P. Additionally, the study found that the process was economically feasible, with energy consumption as low as 0.01974 kWh/m3 at 1.5 mA/cm2. The analysis also highlighted the potential of EC-treated water for reuse in hydroponic systems without adverse effects on crop health. This research is novel in introducing EC specifically for HWS treatment, presenting it as a scalable and environmentally friendly solution that addresses pressing environmental concerns and enhances the sustainability of hydroponic farming operations.