Abstract

MARTINEZ JARDINES, Luis Gerardo; MARTIN ROMERO, Francisco; GUTIERREZ RUIZ, Margarita Eugenia  and  CENICEROS GOMEZ, Águeda Elena. Evaluation of the removal of arsenic and cadmium from aqueous solution using natural rhyolitic sediments and metallurgical wastes. Rev. Int. Contam. Ambient [online]. 2012, vol.28, n.3, pp.237-249. ISSN 0188-4999.

The use of natural materials abundant, efficient and inexpensive for use in stabilization of contaminants is in development, so some sorbent materials for removal of Cd (II) on aqueous solutions in the range of 10-100 mg/L and for As (III) and As (V) in the range of 1-500 mg/L have been investigated. The sorbent materials studied are indigenous rhyolitic sediments and metallurgical wastes from San Luis Potosi, México. Mineralogical analysis showed that rhyolitic sediments are characterized by the occurrence of clay minerals, while the metallurgical wastes are characterized by Fe-bearing minerals as ammoniojarosite, K-jarosite, hematite and goethite. The experimental results showed that the rhyolitic sediments had high removal efficiency (94-99 %) for Cd (II); while As (III) was barely removed (5-18 %) and As (V) was not retained by these natural geological materials. By contrast, the removal of As (III) and As (V) by metallurgical wastes had an efficiency of 88 and 77 %, respectively. However, these wastes were not able to remove Cd (II). The experimental results were fitted to the Linear, Langmuir, and Freundlich isotherm models to obtain the characteristic parameters of each model. The Linear model for As (III) on rhyolitic sediments, as well as the Langmuir model for Cd (II) on rhyolitic sediments and As (III) and (V) on metallurgical wastes, were found to well represent the measured sorption data.

Keywords : arsenic; cadmium; rhyolitic sediments; metallurgical waste; sorption isotherm.