The Removal of Fe, Zn, Cu, and Pb from Wastewaters Using Chabazite Zeolites Produced from Southern Brazilian Coal Ashes

摘要

The use of the southern Brazilian coal ashes generated in power plants for the production of zeolites can constitute an alternative and noble use for a residue which has historically contributed for the degrading of vast areas. Brazilian's largest coal mine ― Candiota ― is located in the state of Rio Grande do Sul close to the borderline with Uruguai. The practice in Candiota, an open pit mine, is to use exhausted areas for the disposal of the ashes not commercialized (around 70%). As far as the disposal of ashes is concerned, a good improvement has been done, particularly during the last 5 years, with the adoption of proper techniques for the soil recovery. Despite that, the presence of old deposits dating from the sixties associated with the natural conditions of the surrounding soil has contributed to the contamination of the region's surface waters, particularly with metals. It is shown here that a Chabazite zeolite can be used for the reduction of the region's water metal content with good results. That is, the region's main residue is used for the production of a material which can help to reduce the environmental impact associated to its disposal.