Industrial processes are activities that produce large amounts of wastes. Often these wastes are disposed in dam or landfills, occupying large areas and causing environmental damage such as the contamination of water and soil. According to the Circular Economy concept, waste should be minimized and reused as raw material in a new process. This work describes two residues, namely red mud (bauxite residue) and waste foundry sand (WFS), whose chemical compositions indicate their suitability for use as protective coatings. These residues were used to obtain coatings on aluminum alloy by employing plasma electrolytic oxidation (PEO). The PEO process enables the creation of coatings that are durable, uniform, and strongly adherent on metallic components of different shapes. The mineralogical compositions of the coatings were investigated using X-ray diffraction (XRD). Surface wettability was determined by contact angle measurements and evaluation was made of the average surface roughness. Alumina was the main phase observed by XR, indicating good chemical stability and high thermal resistance. The coatings obtained with the red mud were thicker and less rough, compared to those obtained with the WFS. The results demonstrated the feasibility of using these wastes for coating metals in order to improve their properties and enable new applications. Keywords: Industrial Waste, Red Mud, Waste Foundry Sand, Circular Economy, Ceramic Coating.

Abstract:This work aimed to evaluate the physical, chemical, microbiological and parasitological parameters in a composting system of Vegetable Solid Residues (VSR). The work was carried out during four months and was constituted of a compost bed of 12 m 3 of volume and the proportion used for its filing was of 6:1 (VSR: Sawdust). For the analysis of the microbiological and parasitological parameters16 sample collections were carried out for each parameter, at weekly intervals. The presence of Total Coliforms (TC), Thermotolerant Coliforms (TTC) and Intestinal Parasite Eggs (IPE). Regarding the physical and chemical parameters were analyzed: Temperature, pH and the Carbon and Nitrogen Relation (CNR). For the physical and chemical parameters the results revealed that there was a reduction in the CNR, with the final value of 14. The temperature presented little increase in the first five weeks, with the average value of 38.98°C and its stabilization in the last week with average value of 29.3°. The pH oscillated between neutrality to slightly acid. There was no reduction in the TC, but for the TTC there was a decrease in its count of 98.54%. In relation to the IPE, the composting system was capable of inactivating and eliminating them.