Removal of Cr (III) from contaminated water using industrial waste of the cassava as natural adsorbents

This innovative research aimed to study the potential of the use of solid wastes from cassava root processing industry (Manihot esculenta Crantz) (peel, bagasse and the mix peel + bagasse) as natural adsorbents of Cr3+ from waters. In a first step, the biosorbents were characterized chemically, structurally and morphologically. This way were performed infrared spectrum analysis, scanning electron microscopy, point of zero charge and chemical composition for all studied natural adsorbents. After that, studies evolving kinetics, equilibrium, thermodynamics and desorption of Cr3+ were performed. According to the obtained data the cassava adsorbents proved to be efficient in the removal of Cr3+, being found in Langmuir and D-R models the best fitting, indicating monolayer chemisorption, with endothermic character. The cassava materials presented lower rates of desorption also suggesting a chemisorption of Cr3+ molecules. By the obtained results it was concluded that the use of cassava biosorbents are viable for the decontamination of waters containing Cr3+, being the use of cassava wastes for adsorption a complementation of the final steps of cassava productive chain.    Key words: Contamination of waters, chromium toxicity, biosorbents, natural adsorbents, remediation of waters, biosorption, decontamination of water.