In order to understand the experimental result, we found that it was essential to include treatment of van der Waals interaction for water purification & in general it is always the dominant contribution to the adsorption energy. Charcoal is the outcome of pyrolysis carbonaceous source material & had excellent adsorption capacity. It makes this filter unique is the use of chemical adsorption of charcoal which is not commonly used in water purification.

Keywords : Charcoal; Filter cloth; Sanitation; Microporosity; van der Waals interaction; Chemical adsorption.