2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 7: Energy Production, Environmental & Multiscale
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 528 pages |
| ISBN: | 978-1-987820-09-6 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Development of an arsenic stabilization method to remediate wastes and soils and its use to improve the security of metallurgical waste disposal sites
Margarita Gutierrez-Ruiz1; Francisco Romero1; Agueda Ceniceros1; Gerardo Martinez1; Tania Tavares2;1UNAM, Mexico, Mexico; 2DEPARTMENT OF ANALYTICAL CHEMISTRY, INSTITUTE OF CHEMISTRY UFBA, Salvador, Brazil;
Type of Paper: Regular
Id Paper: 144
Topic: 8
Abstract:
In a contaminated terrain of 432.6 ha located in San Luis Potosi, Mexico, where lead and copper smelters and an arsenic trioxide plant had operated for nearly a century, the geochemical behavior of arsenic in soils and wastes was studied and field experiments conducted in order to stabilize this element. The analyses indicated that most of the soils contained As (V), but in the soils of the surrounding area of the arsenic trioxide plant, high concentrations of arsenic (III) were detected. Field experiments were carried out to evaluate As stabilization of soils based on the encapsulation of As (III) with cement and/or chemical stabilization. The chemical process was an oxidation with a waste rich en Mn (IV) with a subsequent precipitation absorption of the As (V) formed. The stabilization treatments reduced the As soluble concentration with different efficiencies. In all cases the reduction of As solubility in most of the treated soils was significantly reduced at levels lower than the maximum permissible As soluble concentration of the NOM-147 (0.5 mg/L). Although the lowest efficiency was obtained using Mn-waste and sulfuric acid, the best environmental and economic solution is to create a safe geochemical barrier in the hazardous waste safe disposal site built in the study area. Mn-waste together with jarosite and rhyolitic materials, form an excellent control to the solubility of cationic and anionic inorganic toxic species.