Keratin and Chitosan Biosorbents for Wastewater Treatment: A Review

Heavy metal ions and their toxic complexes with minerals and organic matter significantly affect the quality of water bodies. Such metallic complexes and excessive minerals are of non-biodegradable nature posing a serious threat to fauna, flora, and human health. Therefore, removal of metal ions and organic matters from water is highly desirable in benign chemistry. Over the years, biomaterials have increasingly become important in green chemistry and they have been trialed to eradicate heavy metals from water successfully. Nevertheless, mechanistic understanding of biosorption process still requires investigation in laboratories before the process is applied in industries. In this review, we elaborated exclusively chemistry and applications of most common biomaterials such as keratin, chitosan, and their derivatives for reclamation of water polluted by heavy metals. Biosorption efficiency is increased by changing the surficial morphology of applied biopolymer by chemical modification. Keratin and chitosan operate through active polar sites on their surface to attract the charged metal ions via physical and chemical surficial mechanism. This review can be noteworthy for chemists, biologists and environmentalists working in the research area of water quality and related disciplines.