Utilização de zeólitas sintetizadas a partir de xisto retortado na remoção de arsênio em águas contaminadas

Abstract

The solid by-product of the oil shale processing (PETROBRAS-Brazil) was used as raw material to synthesize zeolites A and faujasite. Alkaline fusion followed by hydrothermal treatment was the synthesis procedure used, and five different starting material compositions were obtained. The more crystalline zeolite-type materials synthesized, the pretreated oil shale ash and commercial zeolites were used as adsorbents in the purification of pollutant solutions with arsenic. The zeolite-type material composed of a mixture of zeolite A (42.6%) and faujasite (52.9%) presented an ion exchange capacity comparable to the pure zeolites A and faujasite, much better than the pretreated ash.

Arsenic toxicity to cladocerans isolated and associated with iron: implications for aquatic environments

“…Furthermore, mitigation and remediation actions in the environment have been used in processes involving precipitation or adsorption of this ametal mainly to oxides and hydroxides iron (Meng et al 2002, Zaw and Emett 2002, Fernandes-Machado and Miotto-Bigatão 2007.…”

Water adsorption in hydrophilic zeolites: experiment and simulation

“…In particular, zeolite LTA4A is widely used to separate polar from non-polar molecules by permeation, as this zeolite is highly hydrophilic due to its low Si/Al ratio 1 . For example, LTA4A has proven to be useful in alcohol dehydratation [2][3][4] , pollutant removal from water 5,6 , or even as working medium in the refrigeration of thermal machines 7 .…”

“…In particular, zeolite LTA4A is widely used to separate polar from non-polar molecules by permeation, as this zeolite is highly hydrophilic due to its low Si/Al ratio. 1 For example, LTA4A has proven to be useful in alcohol dehydration, [2][3][4] pollutant removal from water, 5,6 or even as working medium in the refrigeration of thermal machines. 7 Experimental adsorption isotherms of water in zeolites provided by different research groups often show large deviations, 8,9 mainly due to imperfections in the zeolite crystals, cation relocation, or indetermination in the location of the Al atoms in the zeolite structure.…”