A comprehensive study on the bacterial biosorption of heavy metals: materials, performances, mechanisms, and mathematical modellings

Abstract

Abstract Discharges of waste containing heavy metals (HMs) have been a challenging problem for years because of their adverse effects in the environment. This article provides a comprehensive review of recent findings on bacterial biosorption and their performances for sequestration of HMs. It highlights the significance of HM removal and presents a brief overview on bacterial functionality and biosorption technology. It also discusses the achievements towards utilisation of bacterial biomass with biosorption of HMs from aqueous solutions. This article includes different types of kinetic, equilibrium, and thermodynamic models used for HM treatments using different bacterial species, as well as biosorption mechanisms along with desorption of metal ions and regeneration of bacterial biosorbents. Its fast kinetics of metal biosorption and desorption, low operational cost, and no production of toxic by-products provide attraction to many researchers. Bacteria can easily be produced using inexpensive growth media or obtained as a by-product from industries. A systematic comparison of the literature for a metal-binding capacity of bacterial biomass under different conditions is provided here. The properties of the cell wall constituents such as peptidoglycan and the role of functional groups for metal sorption are presented on the basis of their biosorption potential. Many bacterial biosorbents as reported in scientific literature have a high biosorption capacity, where some are better than commercial adsorbents. Based on the reported results, it seems that most bacteria have the potential for industrial applications for detoxification of HMs.