DIFFUSION MECHANISM OF LINDANE INTO WOOD CHARCOAL

The wood charcoal treated by 1N HNO3 (WCT) was used to remove toxic ch lorinated pesticide lindane (gamma-HCH) residue from water by the sorp tion process. Using a simple first order reversible kinetics constants and half time equations, the film and pore diffusion coefficients wer e determined. Film diffusion was found to be rate limiting step in sor bing lindane by WCT. This was further authenticated by kinetics studie s at different initial sorbate concentrations, different sorbent sizes , and different agitation speeds besides interruption test. A pore dif fusion model was used to fit the data of kinetics in continuously mixe d batch reactors (CMBR), and the tortuosity, external resistance, and surface diffusion effects on lindane sorption by WCT were noticed. The tortuosity values of 15 to 28 were obtained for WCT-lindane system.