Synthesis and application of adsorbent for removal of organic contaminants

Only a few studies are found on the inspection of the chemical literature on removal of organic contaminants by adsorption with adsorbents prepared in the MOx form. A great majority of the adsorbents that are used in these studies are commercial adsorbents and are either used as purchased or after various modifications. Removal by specific adsorbents, however, is important for some difficult contaminants. Neither synthesis nor application of a specific adsorbent for organic contaminants in the solution phase has been encountered. Based on the adsorption of phenol and 4-nitrophenol, synthesis and application of new adsorbents as alternatives were realized. These new adsorbents were either directly used in the form of alkoxide-hydroxide-oxide and oxide forms, or after being coated with alcoholic solution of the partial hydrolysis product of amino functional silane prepared in dry methanol as 50% (w/w) for adsorption of phenol or 4-nitrophenol in aqueous and/or non-aqueous solutions. The effect of the adsorbate concentration, pH, the amount of the adsorbent, and the contact period on adsorption of the two above mentioned adsorbates were studied and optimum conditions for maximum adsorption were determined. Extent of adsorption was calculated from UV-spectrophotometrical determination of the unadsorbed amount of the species. It was concluded that metal-alkoxide-phenol and metal alkoxide-4-nitrophenol derived adsorbents could be used as specific adsorbents. Key Words: sol-gel process, metal alkoxide, adsorption, adsorbent, phenol, 4-nitrophenol. IV