There are abundant natural materials in the world with diverse field applications. Some of these are well known and familiar to mankind from the earliest days of civilization. Some of these are used as adsorbents in water and wastewater treatment. Adsorption effectively removes specific pollutants from wastewaters and adsorption phenomena in solution systems play important roles in many areas of practical environmental technology. In this chapter, the classification and structure of natural materials and their uses, specifically in relation to adsorption are discussed. Economic aspects of natural materials are also evaluated.
Keywords: Adsorbent, Natural materials, Pollutant, Water treatment, Zeolites, Siliceous material, Clay, Ion exchange capacity, Sorption capacity, Adsorption, Clinoptilolite, Alunite, Perlite, Expanded perlite, Kaolinite, Montmorillonite, Illite, Chlorite, Low cost adsorbents, Vermiculite clay, Surface areas.