The adsorption performance, thermodynamic and kinetic model of high crystallinity Na-p zeolites prepared from oil shale ash for the waste water treatment

Abstract

Abstract The Na-p zeolite using oil shale ash (OSA) as raw material was synthesized by hydrothermal synthesis method. The effects of alkali concentration, acid concentration, crystallization temperature, and crystallization time on the formation of Na-p zeolite were studied. The optimal synthesis conditions for converting oil shale ash into Na-p zeolite are: acid leaching concentration is 10%, NaOH dosage is 7 g, crystallization temperature is 130℃ and crystallization time is 12 h. It is found that adding some coal fly ash to oil shale ash can improve the adsorption performance of zeolite materials. The specific surface and the crystallinity of zeolite prepared from OSA and coal fly ash (CFA) are greater than that of pure OSA. The absorbion experiment results indicate that the zeolite synthesized by adding coal fly ash to the oil shale ash own richer pore structure and higher adsorption efficiency for methylene blue (99.2%). The thermodynamic and kinetic processes of methylene blue adsorption by pure oil shale ash, zeolites synthesized from oil shale ash, and zeolites synthesized from oil shale ash with coal fly ash have been systematically studied. These results reveal that the zeolite synthesized in the present study with high absorption can be used as a promising material for the wast water treatment.