Application of Biochar for the Removal of Cadmium from IndustrialWaste

Abstract

The growing levels of cadmium (Cd) in environmental contexts substantially threaten public health and ecosystems. This research explores the effectiveness of biochar produced from agricultural waste as a sustainable material for capturing cadmium ions from industrial wastewater by employing batch adsorption experiments conducted under controlled laboratory conditions. The experimental factors considered were contact time, initial cadmium concentration, pH, and biochar dosage were meticulously analyzed. The findings revealed a swift adsorption process, achieving over 85% cadmium removal in just 65 minutes. The optimized pH for optimal cadmium adsorption was determined to be 7.0, which minimized competitive ion interactions. The adsorption equilibrium was described by both Freundlich and Langmuir isotherm models, with Langmuir demonstrating a more accurate fit (R²= 0.9569), suggesting the presence of monolayer adsorption on a surface with a limited number of identical sites. Kinetic studies indicated that the adsorption followed a pseudo-second order model, highlighting the significance of chemisorption due to the high equilibrium adsorption capacity values (qe) ranging from 3.709 to 7.880 for pseudo-second order compared to 6.720 for pseudo-first order. Conclusively, this shows that biochar is a viable and sustainable substrate that can be efficiently utilized for combating cadmium contamination in industrial waste streams. Thus, enhances environmental
conservation and resource recovery initiatives.