Electrochemical process supported by Niger seed husk biochar for efficient removal of contaminants from coffee processing wastewater

Abstract

The present study investigates the potential of biochar-assisted-electrochemical oxidation (BAECO) for treating wastewater from the coffee processing industry. An integrates electrochemical oxidation (ECO) with biochar adsorption to enhance pollutant removal efficiency. The study evaluates the removal of chemical oxygen demand (COD), color, turbidity, nitrate, and phosphate, under different operational conditions. The biochar adsorbent was extensively characterized using Fourier Transform Infrared Spectroscopy (FTIR) to analyze functional groups and X-ray Diffraction (XRD) to determine crystalline structure. These analyses provided insights into the physicochemical properties of biochar and its role in pollutant adsorption. Key experimental parameters, including pH, applied electric current, and electrolysis duration were optimized to achieve maximum treatment efficiency. The results demonstrate that niger seed husk biochar (NSHB)-assisted electrochemical oxidation significantly improves the pollutant removal compared to conventional methods. Under optimal conditions (pH 7, current of 0.40 A, biochar dosage of 1.5 g/L, and 40 minutes of electrolysis), the BAECO system achieved significant removal efficiencies: COD (98.64%), color (99.11%), nitrate (97.22%), and phosphate (92.28%), respectively. These findings confirm that integrating biochar adsorption with electrochemical oxidation provides an efficient and sustainable approach for treating coffee processing wastewater, contributing to improved water quality and resource recovery in the industry.