No abstract

No abstract

Adsorbent materials used for treating industrial pollutants are reviewed. The article consists of two parts. The first part considers new trends in traditional adsorbents such as activated carbons and zeolites. New low-cost adsorbents such as waste materials and clay minerals are discussed in the second part. It has been reported that activated carbons can be obtained from agricultural by-products such as shells and stones of various fruit by a simple single-stage method. This method differs from the traditional processes for the production of activated carbons. On the other hand, natural zeolites have been used as low-cost adsorbents in industrial pollution control. The extent of their application is not only related to their low cost, but also to the improved properties and performance characteristics which they possess. Recently, a variety of agricultural and industrial waste materials and clay minerals have been evaluated as new adsorbents with an excellent potential for the removal of different pollutants from wastewater. The new low-cost adsorbents obtained were found to have large adsorption capacities and good mechanical properties.

Equilibrium conditions of adsorption of a basic dye on hardwood sawdust were studied using the Langmuir and Freundlich isotherms. Two sets of experiments were carried out at different particle sizes and temperatures. The adsorption of the basic dye on hardwood was found to conform with the two isotherms. The capacity of hardwood for the adsorption of basic dye was found to increase by decreasing the particle size and increasing the temperature. The cost of hardwood adsorbent is only 8.4% that of activated carbon.

A B S T R A C T