Development of Corncob-Based Biochar-Cellulosic Matrix for Heavy Metal Sequestration from Wastewater

Abstract

Freshwater contamination by heavy metals poses significant threats to human health and the ecosystem. This research explores the use of corncob-based biochar-cellulosic matrix for remediation of heavy metals from wastewater. Biochar-cellulosic composites were prepared in varying ratios (0:1, 1:2, 2:3, and 1:1) of biochar to cellulose. The physicochemical properties of wastewater and heavy metal (lead, copper, zinc, chromium and cadmium) quantification were determined using standard procedures. Acid hydrolysis and alkaline treatment was adopted for cellulose extraction while the biochar was produced through pyrolysis of corncob. The functional groups of the matrix were characterized using FTIR spectroscopy. The result showed that extraction of cellulose from corncob had a yielded of 33.65 %. Treatment of wastewater with the matrix resulted in significant improvements in water quality parameters, with reduction in turbidity from 423.0 NTU to 78.0 NTU, total dissolved solid (TDS) decreased from 60.6 to 35.5 mg/l, conductivity reduced from 49.2 to 39.3 nS/cm, while maintaining pH levels between 7.6-8.3 and temperature ranged between 28.0-29.5 °C. Wastewater treatment with the matrix also demonstrated significant reduction in heavy metal concentration. Lead decreased by 94.74 %, copper concentration was reduced by 58.33 %, zinc concentration decreased by 48.11-64.15 %. Furthermore, chromium concentration in wastewater reduced by 77.78 % while 42.86-85.71 % reduction was observed for cadmium. These findings demonstrated that corncob-based biochar-cellulosic matrix, particularly at a 1:1 ratio, offers a promising, sustainable solution for wastewater remediation, effectively removing heavy metals while improving overall water quality parameters.