Preparation of novel diatomite-based composites: applications in organic effluents sorption

A new diatomite-based composite is prepared and used for environmental remediation. The Algerian diatomite has been used for the first time for this application. Preparation conditions showed increased surface area with improved sorption properties. This composite consisting of diatomite (Dia) and activated carbon (C) was prepared using a mixture of diatomaceous earth and glucose. Effects of thermal and chemical treatments are studied. methylene blue (MB), methyl orange (MO) and para-nitro-phenol (PNP) from aqueous solution were chosen as pollutants to test retention capacity. Physical, chemical and structural properties of these new hybrid materials have been investigated by several methods. The surface areas of pure and modified diatomite are estimated to be (22m(2)g(-1)) and (100-173m(2)g(-1)), respectively. Sorption kinetics and isotherms for MB, MO and PNP were carried out in order to determine their respective adsorption capacity. The surface charges (negatives) and macroporosity of diatomite did not allow the adsorption of PNP and MO. However, modified diatomite (Dia/C) showed ability to eliminate these pollutants, despite their dominant inorganic nature. The pseudo-second-order kinetics and the Langmuir model described sorption data reasonably well. The study showed that the composite materials can be used as potential efficient sorbents.