Removal mechanism of endosulfan sorption onto wood charcoal
by Sudhakar Yedla, A.K. Dikshit
International Journal of Environment and Pollution (IJEP), Vol. 15, No. 5, 2001

Abstract: Endosulfan is among the most widely used pesticides in developing countries and other parts of the world and has been found to contaminate various parts of the environment, including drinking water sources. In an earlier study to find a suitable adsorbent to remove endosulfan, wood charcoal was found to give promising results. In the present study, the process controlling the rate of endosulfan sorption onto wood charcoal and the mechanism of removal were examined using various methodologies. Both film and pore diffusion coefficients were determined, and the linearity of the rate constants of adsorption with initial endosulfan concentrations revealed the process to be controlled by film diffusion. This was supported by the linear fit of the rate constants with the inverse of the diameter of adsorbent particles and the change in adsorption rates with agitation speed. Multiple interruption tests also revealed that endosulfan sorption onto wood charcoal is controlled by film diffusion. The increase in reaction rate constant with temperature and isosteric heat of adsorption in the range of -2.655 to 5.185 kcal/mol implied that the endosulfan removal process was endothermic in nature. The activation energy of 2.33 kcal/mol, which was less than 12 kcal/mol, revealed that the removal mechanism could be attributed to physisorption with a major contribution of van der Waals and electrostatic forces.

Online publication date: Mon, 19-Jul-2004

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Environment and Pollution (IJEP):
Login with your Inderscience username and password:

    Username:        Password:         

Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email