Environmental Remediation and Sustainable Approaches to Heavy Metal Removal: A Comprehensive Review of Biosorption Technique

Abstract

Heavy metal- laden contaminated water poses severe environmental threat due to the tendency of bioaccumulation, persistent nature and toxicity. Conventional wastewater treatment techniques like Ion exchange, chemical precipitation, membrane separation, electrocoagulation can result into secondary pollutants, requires high energy use and involve high cost.  This review discusses environmentally friendly methodologies for the removal of heavy metals from aqueous streams, and the biosorption process is a viable alternative addressing sustainability concerns to the conventional, energy-intensive processes of industry. The biosorption process utilizes a wide range of natural biomasses, like plants, fungi, algae, and bacteria, in the sequestration and removal of heavy metals from aqueous solutions. Biosorption is mediated through various mechanisms, including physical adsorption, ion exchange, complexation, precipitation, and intracellular transport. The effectiveness of a biosorbent will be based on the efficiency of sequestration and removal of the heavy metals under given conditions. Some of the important factors affecting this include pH, temperature, contact time, biomass loading, and initial heavy metal ion concentration in solution. Additionally, biosorption's capacity for regeneration and reuse increases its commercial viability.

This work explores the sources of biosorbents and driving forces that govern their biosorption efficiency. Furthermore, this work provides in-depth discussion of the factors affecting the effectiveness of the process. It establishes the fundamental understanding of biosorption mechanisms and influencing factors, paving the way for the future commercialization of this promising technology.