A Review on the Mitigation of Heavy Metals from Aqueous Solution using Sugarcane Bagasse

Man’s battle against pollutants in his quest for clean water and a cleaner environment has been justified to be beneficial not just to himself but also to every other animal. One of such pollutants is the heavy metals which are non-biodegradable and through their bioaccumulation in living tissues can cause mild to severe breakdown in living organisms. This review centers on the removal of these heavy metals from aqueous solution using a very cheap and readily available agricultural waste—Sugarcane Bagasse. In this research, the effect of the various modifications on sugarcane bagasse through their maximum adsorption capacities, isotherms, kinetic models, mechanism of adsorption and thermodynamic models were studied. It was observed that modification significantly improved the adsorption capacity of the sugarcane bagasse and the maximum sorption capacity recorded for Cu(II), Cd(II), Cr(III), Cr(VI), Ni(II), Pb(II), and Zn(II) were 268.0 mg/g, 320.0 mg/g, 82.99 mg/g, 3.956 mg/g, 167.0 mg/g, 700.0 mg/g, and 200.0 mg/g, respectively, all of which were modified sugarcane bagasse except for Cr(VI). It was observed that the adsorption mechanism was mostly due to electrostatic interaction and ion exchange and the best fit isotherm was mostly Langmuir or Freundlich and pseudo-second-order kinetic model was the best-fit kinetic model in most cases. Some research gaps were also stated to aid future researches as sugarcane bagasse has shown to be a very promising bio-adsorbent for the adsorption of heavy metals.