The Use of Biosorbents in Water Treatment
Mothusi Molebatsi, Bonang Nkoane, Ngonye Keroletswe, Samuel Chigome, Moses T. Kabomo
Abstract
Biosorbents are materials of biological origin (microbial, biomass-derived waste, or industrial by-products) used to adsorb or absorb pollutants. They have been used to remove various contaminants, including heavy metals, dyes, and pharmaceuticals. Their effectiveness is due to the different functional groups that interact with pollutants, including hydroxyl, amino, carboxyl, and phosphate groups. This review explores the various kinds of biosorbents (classification), mechanisms, and factors influencing biosorption, such as biomass content, time, temperature, pH, and concentration of pollutants, synthesis methods of biosorbents, and the current state of research on biosorbents. The review highlights the advantages of biosorbents, along with the challenges encountered, such as difficulty in regeneration and variability in performance. Finally, the review identifies research gaps and future directions, including exploration of modified/synthetic biosorbents for the removal of multi-component pollutants.