THERMODYNAMIC STUDIES FOR ARSENIC REMOVAL FROM GROUNDWATER IN TORREON MEXICO
Arsenic contamination is an enormous worldwide problem. In Torreon Mexico, Arsenic contaminated natural waters, including surface water and ground water, are a significant problem as some of these compounds are known as toxic, mutagenic, and carcinogenic. Groundwater arsenic contamination in Torreon Mexico was first reported 30 years ago 1. Arsenic concentration has been found in well water from several communities ranging from 0.25 to 1.0 ppm. The elevated concentration of arsenic in water, above that originating from natural sources, has been attributed to the use of organo arsenical pesticides in the cotton fields and also to the millions of tons of waste slag generated at a local lead/zinc smelter 1.A very promising electrochemical treatment technique that does not require chemical additions to remove arsenic is electrocoagulation (EC) with air injection. The purpose of this research was to investigate the thermodynamic of arsenic adsorption on iron species using the Langmuir’s Isotherm. Also, thermodynamic parameters such as ΔH°, ΔS° and ΔG° were calculated and the adsorption process found to be exothermic and spontaneous. Powder X-ray Diffraction, Scanning Electron Microscopy, and Transmission M.ssbauer Spectroscopy were used to characterize the solid products formed at iron electrodes during EC. The results of this study suggest that magnetite particles and amorphous iron oxyhydroxides are present in the examined EC products and in this study indicate that arsenic can be succesfully adsorbed on iron species by electrocoagulation process. Field pilot-scale study demonstrated the removal of As(Ⅲ)/As(Ⅴ) with an efficiency of more than 99％ from both wastewater and wells.
arsenic removal electrocoagulation adsorption magnetite particles
J. R. PARGA DR. J. L. VALENZUELA
Instituto Tecnológico de Saltillo, Saltillo Coah. , México Universidad de Sonora, Hermosillo Sonora, México
国际会议
北京
英文
13-19
2010-05-17（万方平台首次上网日期，不代表论文的发表时间）