Author(s)

R. Sasai, T. Mizutani & H. Itoh

Abstract

It is necessary to develop a novel method for preparing useful functional materials from the industrial solid wastes (ISWs) so as to decrease the amount of ISWs landfilled in the dump yard. The preparation of the carbon/zeolite (CZ) composites from the inorganic/organic ISWs mixture was investigated. Coal fly ash (CFA) and sawdust (SD) were used as inorganic and organic ISWs, respectively. After adding the activator (Na2CO3 or K2CO3) in aqueous solution to the mixture of CFA, SD, and bentonite as caking additive, the mixture was kneaded and extruded as a cylindrical shape. The dried green body was activated at 600 to 850oC for 1 hour in N2 atmosphere. This activated cylindrical black body was hydrothermally treated in a Teflon-sealed pressure vessel with 2 mol/dm3 NaOH aqueous solution at 120oC for 24 hours. The XRD patterns of the prepared composites had diffraction peaks of P-type zeolite together with quartz and mullite contained in the original CFA. It is found that the CZ bulk composites can be prepared by the hydrothermal alkalin treatment of the reagentactivated bulk body. The CZ composites with Na2CO3 prepared at 700oC had a specific surface area of 1,300 m2/g-carbon and a cation-exchangeable capacity of 180 mequiv./100g-inorganic. This result indicates that the present material can remove simultaneously both non-polar and cationic contaminants from wastewater. 1 Introduction In Japan, nearly 40 million tons of the industrial solid wastes (ISWs) are discharged every year. The total amount of these ISWs is reduced by some kinds

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