DEVELOPMENT OF LOW COST ADSORBENTS FOR THE REMOVAL OF HEAVY METALS FROM SYNTHETIC WASTEWATER

Abstract

Wastewater generation is a massive problem not only in India but all across the world. Wastewater is generated from industrial and domestic sources. One of the major constituent of the industrial wastewater is heavy metals. Heavy metals are extremely hazardous and pose great threat to the environment. Many of the conventional physico-chemical techniques used for heavy metal removal have their inherent advantages and disadvantages, the cost being a major factor along with the generation and disposal of sludge. The need of the hour is the viable usage of low cost, eco-friendly techniques for the heavy metal removal from wastewater. Adsorption using Raw Laterite soil, fly ash and bagasse has been studied in the following work. The adsorbents were chosen for the study due to their low cost and wide availability. In the present study the metal uptake ability of the adsorbents were tested in batch mode. The Raw laterite soil was chosen as the best adsorbent and was further studied. The various process parameters such as contact time, adsorbent dose, pH and the effect of initial concentration were optimized and examined. The laterite soil showed the best adsorption capabilities at the adsorbent dose 10g/L, at the contact time of 4 hr and at pH 6, the temperature was kept constant at 305K and the rpm at 150. The equilibrium and kinetic studies were performed for the better understanding of the various design parameters. The adsorptive study followed a pseudo-second order model and the Freundlich isotherm was found to fit best to the data generated. Multicomponent adsorption was carried out using raw laterite soil and the data generated fitted well with the Extended Freundlich adsorption isotherm model.