Na-alginate coated waste banana-derived biochar composite for heavy metals removal and parametric optimization using RSM-CCD model

Wastewater treatment is a key research focus due to the ever-increasing water pollution, while the findings on novel material combinations are becoming challenging. The present research aims to develop alginate-modified biochar from the waste banana stems biochar and investigate parametric optimization using the response surface methodology model. Analytical characterization showed the coating of sodium alginate on the surface of biochar (Scanning electron microscope), and the presence of OH, COOH, and C=O functional groups can aid high metal adsorption (Fourier transform Infrared spectroscopy). Parametric optimization was studied (pH, contact time, and adsorbent dose) with an experimental design using CCD-RSM, the variation in ANOVA with a p-value (<0.05) proved RSM model fit with obtained maximum removal efficiency at the optimum parametric condition as pH-6, contact time 60 min, and 0.5 g alginate combined biochar composite for multi-metals aqueous environment. Kinetics and isotherms studies best fit with (PSO) and the Freundlich. The removal efficiency of mixed metals from industrial wastewater was achieved as 87.75% for Cd, 90.11% Co, 82.99% Cr, and 90.60% Ni. The study implied that the parametric optimization through response surface methodology and alginate-modified biochar could be a potential approach for the treatment of heavy metal-contaminated wastewater.