Strength and heat evolution of concretes containing bagasse ash from thermal power plants in sugar industry

An inexpensive and effective adsorbent was developed from bagasse fly ash, obtained from a sugar industry, for the dynamic uptake of lead and chromium. Lead and chromium are sorbed by the developed adsorbent up to 96-98%. The removal of these two metal ions up to 95-96% was achieved by column experiments at a flow rate of 0.5 mlmin(-1). The adsorption was found to be exothermic in nature. The adsorbent was successfully tried for the removal of lead and chromium from wastewater in our laboratory. The developed system for the removal of two ions is very useful, economic, rapid, and reproducible.

The bagasse fly ash, an industrial solid waste of sugar industry, was used for the removal of cadmium and nickel from wastewater. As much as 90% removal of cadmium and nickel is possible in about 60 and 80 min, respectively, under the batch test conditions. Effect of various operating variables, viz., solution pH, adsorbent dose, adsorbate concentration, temperature, particle size, etc., on the removal of cadmium and nickel has been studied. Maximum adsorption of cadmium and nickel occurred at a concentration of 14 and 12 mg x l(-1) and at a pH value of 6.0 and 6.5, respectively. A dose of 10 g x l(-1) of adsorbent was sufficient for the optimum removal of both the metal ions. The material exhibits good adsorption capacity and the adsorption data follow the Langmuir model better then the Freundlich model. The adsorption of both the metal ions increased with increasing temperature indicating endothermic nature of the adsorption process. Isotherms have been used to determine thermodynamic parameters of the process, viz., free energy change, enthalpy change and entropy change.