PHYSICOCHEMICAL CHARACTERISTICS OF ADSORBENTS DERIVED FROM WASTE RAW MATERIALS

Abstract

Efficient use of industrial waste and prevention of environmental damage caused by industrial enterprises are closely connected and relevant issues in the modern world. This research is focused on obtaining zeolite adsorbents based on wastes from the oil and gas refining industry and the energy sector of the Republic of Uzbekistan, as well as on local mineral raw materials for subsequent use in addressing environmental issues. Potential raw materials - zeolites deactivated through purification and drying of natural gas, samples of fly ash - the side-product from energy production by burning the brown coal, wastes from processing of used alumina adsorbent and enriched Angren kaolin – have been studied by means of thermography, diffractometry and scanning electron microscopy. Taking into account high thermal stability, chemical and phase composition of coal wastes, conversion of the fly ash into zeolite structures was made only by preliminary fusion with a mixture of sodium hydroxide and sodium carbonate. Kaolin-based adsorbents resulted from alkaline fusion contained less ballast quartz, but more hydroxysodalite than when zeolite crystallized in granules without a binder. Forming of multiphase adsorbents, including metastable zeolites such as NaA and NaX, as well as stable NaP and hydroxysodalite zeolites, has been experimentally proven. Outcomes from adsorption of toxic organic and inorganic volatile compounds from the gas phase have been presented. Ion exchange properties were studied on the extraction of Ca2+ cations and typical cationic dyes from model solutions of CaCl2, crystal violet and brilliant green