Studies on the Removal of Metal Ions by Adsorption Onto Coconut Shell and Commercial Activated Carbons

摘要

Studies on the removal of metal ions, like mercury, lead and cadmium ions by adsorption on indigenously prepared coconut shell carbon (IPCC) and commercial activated carbon (CAC) have been carried out at 30±1℃ under batch mode. The adsorption data on the variation of (ⅰ) initial concentration of initial ions, (ⅱ) contact time, (ⅲ) dose, (ⅳ) initial pH of the solution and (ⅴ) particle size of IPCC are determined. The percentage removal of metal ions increased with the decrease in initial concentration, ionic strength and particle size of the adsorbent (IPCC) and increased with the increase in contact time, dose of adsorbent (IPCC and CAC) and initial pH of the solution. Adsorption data have been analysed with the help of Freundlich and Langmuir adsorption isotherms and first order kinetic equations, namely an Natarajan-Khalaf, Lagergren and Bhattcharya-Venkobachar equations. The intra-particle diffusion is found to be the rate limiting steps. Indigenously prepared coconut shell carbon (IPCC) is found to be a suitable low-cost adsorbent as an alternative material to CAC in the removal of metal ions.