Biosorption for Eliminating Inorganic Contaminants (IOCs) from Wastewater

Abstract

Water pollution has become a serious concern in the twenty-first century due to the unchecked release of industrial and urban wastewater streams into freshwater sources. Both organic contaminants (OCs) and inorganic contaminants (IOCs) impose grave health and environmental impacts; however, IOCs – particularly heavy metals (lead, arsenic, mercury), anions (fluoride, cyanides, sulfates), mineral acids, and trace elements like selenium – are catastrophic due to bioaccumulation and biomagnification phenomena. Moreover, the presence of IOCs, even in low concentrations, causes significant changes in the physicochemical characteristics of water streams such as pH, biological oxygen demand (BOD), and chemical oxygen demand (COD) and is fatal for aquatic animals, plant life, humans, and environmental sustainability. Therefore, designing and developing commercially viable and highly efficient materials and technologies is imperative for eliminating IOCs from wastewater streams. To date, several wastewater treatment technologies such as photo-catalysis, membrane filtration, coagulation and flocculation, and adsorption have been tested for treating IOC-contaminated water. However, sorption, due to its cost-effectiveness, versatility, and operational simplicity, has emerged as the most promising technology. Among several classes of sorbent materials, biosorbents offer many advantages over traditional adsorbents in terms of scalability, cost-effectiveness, environmental benignity, and technological sustainability. Therefore, a comprehensive review of the role of biosorbents in the removal of IOCs and the present status of the development of these materials is of critical significance to grasp the importance of the research area and ultimately develop novel biosorbents of excellent sorption capacity, outstanding recyclability, promising post-life disposability, and facile commercial viability. Therefore, this chapter explores important aspects of the field, such as sources and hazards of IOCs, along with recent advancements in biosorption technology to eliminate these pollutants from wastewater and future prospects.