Remoção de nitrogênio amoniacal de efluentes utilizando Zeólitas sintetizadas a partir de cinzas de carvão

Abstract

Nowadays there is a growing concern about large scale production of industrial residues, its currently uneconomically viable reutilization and also proper final destination. The bottom ashes of mineral coal fit perfectly this scenario, becoming one of the greatest environmental issues for the companies that use the mineral coal as fuel. Among some reutilization possibilities for this type of residue, there is the transformation of it in a zeolitic material with specific desired characteristics. This alternative has been studied in many countries. In this paper it was studied and applied the hydrothermal process under alkaline conditions for the zeolite synthesis using bottom ashes of mineral coal (lagoon ashes) as raw material. The formation of the desired zeolite (Na-P1) was confirmed through x-rays diffraction analysis. Aiming nitrogen reduction in industrial effluents, there were evaluated tests of ammoniac nitrogen adsorption in a fluidized bed system with internal recirculation and zone of decantation, and in a fixed bed system as well. The obtained results of nitrogen adsorption had been considered adequate for the tests in the fluidized bed system. However, the results found in the fixed bed system had not been satisfactory.