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Encapsulation of sludge from the sewage treatment plants of the clay matrices automotive industry
Authors: César Augusto García Ubaque, María Camila García Vaca, Martha Lucía Vaca Bohórquez
Number of views: 459
This article presents results of a pilot study, where metals leaching from ceramic pieces were made with different mixes of slugde and clay from the sewage treatment plant G.M. COLMOTORES in Bogotá (Colombia). The slugde have been stabilized and solidified in clays and cook in a Hoffman Furnace oven for the fabrication of bricks. The proportions of mixture of clay and sludge for the fabrication of bricks used were: 99:1, 95:5, 90:10, 80:20 and 60:40. Then, the bricks were burned at temperatures between 50 to 1100 ° C. Moreover, clays, sludge and bricks were tested by: X ray diffraction (XRD), X-ray Fluorescence X (XRF), Thermogravimetry (TG), Differential Thermal Analysis (DTA), Atomic Absorption Spectroscopy (AA) and Scanning Electron Microscopy (SEM). Finally, other leaching tests were performed in the bricks (Toxicity Characteristic Leaching Procedure - TCLP) for the determination of heavy metals. Results from this study showed that the clay had a high affinity with the sludge and the bricks showed low levels of leaching. Also, it was considered that 95:5 of clay and sludge was the best mixing ratio for all the metals. The metal with lowest removal percentage was selenium and the highest removal percentages were arsenic, nickel, chrome, zinc and cadmium.