APLICAÇÃO DA LAMA DE BENEFICIAMENTO DE ROCHAS ORNAMENTAIS COMO CATALISADOR NO PROCESSO FOTO FENTON PARA A DESCOLORAÇÃO DE CORANTE EM SOLUÇÃO AQUOSO

Abstract

The extraction and processing of ornamental rocks generate a very significant amount of waste, representing an environmental and public health problem. The residue is a fine-grained compound by rock powder and inputs used in the processing process have a potential economic value. The present study was carried out to evaluate the efficiency of the waste generated in the discoloration of an aqueous solution containing methylene blue dye, such as alternative for treating textile effluents. The samples were characterized by X-ray diffraction, inductively coupled plasma optical emission spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The catalytic properties of the samples were evaluated in the Fenton and photo Fenton reactions at pH 3 and natural pH. The best decolorization efficiency (≈ 95%) was achieved using the GRM catalyst at pH 3, after 5 min of photo Fenton reaction. Importantly, owing to its excellent structural and chemical stability, the samples showed a decolorization efficiency above 95% after 5 consecutive cycles of 30 min of reaction. This innovative strategy not only offers a new prospect for the rational disposal of abrasive mud waste, but also contributes to minimizing environmental impacts, promoting sustainable development in the stone industry.