Removal of cadmium (II) and chromium (VI) from waste water by adsorption onto sugarcane bagasse

Abstract

Effluents from textile, leather, tannery, electroplating, galvanizing, pigment and dyes, metallurgical and paint industries and other metal processing and refining operations at small and large-scale sector contain considerable amounts of toxic metal ions. The toxic metals and their ions are not only potential human health hazards but also to another life forms. Toxic metal ions cause physical discomfort and sometimes life-threatening illness including irreversible damage to vital body system. From the eco-toxicological point of view, the most dangerous metals are mercury, lead, cadmium and chromium(VI).

The analysis of wastewater for trace and heavy metal contamination is an important step in ensuring human and environmental health. This project shows that sugarcane bagasse has rapid adsorption rate and good adsorption capacity for cadmium and chromium. The Cd2+ was found to be dependent on PH and contact time. Sugar cane bagasse exhibits a high degree of Cr (VI) removal and it can be utilized for the treatment of industrial wastes containing chromium (VI) concentrations which are very high. Generally, the project study indicated that sugarcane bagasse can be a good adsorbent material for Cd2+ and Cr(VI) removal from dilute aqueous solutions and also it is cheaper and more efficient to use sugarcane bagasse to remove heavy metals. Most conventional methods are very expensive and impose high cost on the industries in treating such wastes. It is recommended that the adsorption be done at a PH that is almost neutral. There should also be enough contact time to increase the efficiency of the process.