Síntese integrada em condições brandas de zeólitas 4A e NaP1, a partir de cinzas de carvão, para o uso em detergente e descontaminação ambiental

Abstract

The main use of coal is the generation of electricity, which represents 41% of all electricity generated in the world. Coal burning power plants in the southern states of Brazil produce 3.0x106 tons of ash per year. The present work aims the integrated synthesis of zeolites NaP1 and 4A under mild conditions using coal fly ash as raw material. These zeolites present industrial and environmental applications of great importance for the country, aiming at the minimization of environmental impacts and waste generated. For the synthesis of zeolites hydrothermal process was carried out with different concentrations of the NaOH in low cost glass reactor. The liquid/solid ratio, temperature, sources of aluminum, among other factors, was also investigated. Several techniques were used, to characterize the synthesized zeolite, such as SEM, XRD, XRF, CEC, among others. The best zeolitic products were used in the effluents treatment. Under the conditions used in this study NaP1 and 4A zeolites were obtained with CEC values of 2.5 and 4.5 meq g-1, respectively, indicating high conversions. The zeolite NaP1 proved been highly efficient in removing Mn and NH4+, from Acid Mine Drainage and Swine manure effluents, respectively, within the emission limits imposed by legislation. The results of this study indicate that the zeolite 4A is could be used in replacement of the polyphosphate in detergents.