Treatment of Gasifier Based Solid Waste for Preparation of Useful Sorbent and its Application for Lead Removal

Abstract

In this research work, an attempt has been made to prepare useful sorbent from gasifier based solid waste, employing acid/base treatment. The main process parameters (such as acid concentration and temperature of pyrolysis) can affect the characteristics of the obtained activated carbon (expressed in terms of iodine number and methylene blue adsorption and specific surface area). Both treatments had a significant positive influence on sorption properties. The activated carbon presented a BET surface area of 715 m2g-1 and 558 m2g-1 for base and acid treatment respectively. The ability of for the removal of lead from aqueous solutions has been investigated. In the batch tests experimental parameters were studied, including solution pH, contact time and initial metal ions concentration. Maximum 96% removal of lead was observed. Removal of about 50–60% occurred in 20-30 min, and equilibrium was attained at around 60- 80 min. The functional groups (C=O, S=O,–OH) present on the carbon surface may responsible for the adsorption of metal ion. The adsorption parameters were analysed using both the Freundlich and Langmuir models. The data are better fitted by the Langmuir isotherm as compared to Freundlich model. These experimental results indicated the potential use of gasifier based waste as a precursor in the activated carbon preparation process, thus representing an economically promising material.