Preparation and characterization of activated carbon/zeolite composites from industrial solid wastes

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 850degreesC for 1 hour in N-2 atmosphere. This activated cylindrical black body was hydrothermally treated in a Teflon-sealed pressure vessel with 2 mol/dm(3) NaOH aqueous solution at 120degreesC 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 reagent-activated bulk body. The CZ composites with Na2CO3 prepared at 700degreesC had a specific surface area of 1,300 m(2)/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.