In order to contribute to the sustainability of the foundry and construction industrial sectors, this work investigated the possibility of employing used foundry sand (UFS) in soil-cement bricks. Modular bricks were prepared with percentages of 10 wt% cement, 0-25 wt% commercial sand, 0-65 wt% used foundry sand, 25-65 wt% clay, and 15-30 wt% gravel dust. A content of 10 wt% Portland cement was adopted to ensure economic feasibility, and gravel was used to improve mechanical strength. The modular bricks were tested to determine their technical properties. The interfaces between the constituent materials were observed by scanning electron microscopy. In durability tests, the bricks showed water absorption and weight loss in accordance with current technical standards. The addition of UFS together with gravel dust reduced water absorption and provided an acceptable level of mechanical resistance, in accordance with established soil-cement standards. Keywords: soil-cement brick, used foundry sand, building ceramics, solid industrial waste. Resumo A fim de contribuir para a sustentabilidade de indústrias de fundição e de construção, este artigo estudou a possibilidade de areia descartada de fundição (ADF) ser incorporada em tijolos de solo-cimento. Tijolos modulares foram preparados com

The aim of this study was to evaluate the quantity of vanadium removed through electrokinetic remediation applied to catalyst waste used in a fluid catalytic cracking process. In excess, vanadium affects process efficiency by reducing the catalyst's activity, causing deactivation and reducing its useful life in petroleum cracking during refining. The electrochemical reactor used was composed of an extra cathode chamber coupled with an ion-selective cation exchange membrane, Nafion®. The function of the cathode chamber was to increase the overpotential for a hydrogen reduction reaction (HRR) and the electric field to favour metal ion removal. Sodium citrate was used for electrolyte remediation (complexing vanadium) at 0.5 mol/L with an 11.0 V (ε =0.5 V/cm) potential applied. The treatment efficiency was analysed based on the vanadium ion concentration in the electrolyte collected. The results show that electrokinetic remediation using the dual cathode chamber yielded more metal removal and lower energy consumption.

The electrokinetic remediation process, through the application of electric potential and different electrolytes, aimed at mobilizing and removing contaminant metals in spent catalytic cracking catalysts. In this study, FCC spent catalysts were studied after the remediation process with three different electrolytes (solutions of sodium citrate, sulfuric acid or citric acid). The techniques of XRD, XRF, NMR and EPR were used in order to evaluate the changes. The results indicated that the electrokinetic remediation tends to reorganize the internal structure of the catalyst, recovering part of the crystallinity and removing a percentage of the contaminants.

RESUMO -O crescente desenvolvimento do setor petrolífero e a consequente geração de resíduos advindos dessas atividades tem demandado inúmeras pesquisas em diversos setores tecnológicos, visando uma eficiência ambiental em sua destinação. O processo de remediação eletrocinética vem ao encontro desta necessidade, aplicando potencial elétrico ao sistema para a mobilização e remoção dos metais aderidos ao material em tratamento. No presente trabalho, o catalisador desativado de FCC foi remediado com o emprego de soluções de citrato de sódio e ácido sulfúrico como eletrólitos, junto a aplicação de potencial elétrico de 11 V durante 48 h. O material tratado foi analisado através da técnica de FRX para a determinação do teor de níquel e vanádio antes e após o tratamento. A remediação ácida removeu 24% de V, enquanto a alcalina removeu 29% de V. Para as duas condições a remoção de níquel foi próxima a 2%. Vislumbra-se assim o potencial de aplicação da técnica para a regeneração deste tipo de material.