title: Leaching behavior and chemical stability of copper butyl xanthate complex under acidic conditions.
abstract: Although xanthate addition can be used for treating copper-containing wastewater, a better understanding of the leaching toxicity and the stability characteristics of the copper xanthate complexes formed is essential. This work was undertaken to evaluate the leaching behavior of copper xanthate complex precipitates by means of toxicity characteristics leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) using 1 N acetic acid solution as the leachant. Also, the chemical stability of the copper xanthate complex during extraction has been examined with the studying of variation of chemical structure using UV-vis, Fourier transform infrared and X-ray photoelectron spectroscopies (XPS). Both TCLP and SDLT results showed that a negligible amount of copper ion was leached out from the copper xanthate complex precipitate, indicating that the complex exhibited a high degree of copper leaching stability under acidic conditions. Nevertheless, chemical structure of the copper xanthate complex precipitate varied during the leaching tests. XPS data suggested that the copper xanthate complex initially contained both cupric and cuprous xanthate, but the unstable cupric xanthate change to the cuprous form after acid extraction, indicating the cuprous xanthate to be the final stabilizing structure. Despite that, the changes of chemical structure did not induce the rapid leaching of copper from the copper xanthate complex.
authors.affiliation: Department of Environmental Engineering, National Cheng Kung University, 1 Ta-Hsueh Rd., city 70101, Tainan, Taiwan, ROC.
authors.forename: Yi Kuo
authors.initials: YK
authors.lastname: Chang
authors.forename: Juu En
authors.initials: JE
authors.lastname: Chang
authors.forename: Li Choung
authors.initials: LC
authors.lastname: Chiang
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D003300:Copper / Q000737:chemistry* / Q000633:toxicity; D004784:Environmental Monitoring / Q000379:methods; D006256:Hazardous Waste / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D013052:Spectrometry, X-Ray Emission; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013871:Thiones / Q000737:chemistry* / Q000633:toxicity
chemical_list: D006256:Hazardous Waste; D013871:Thiones; C025099:butylxanthate; D003300:Copper; D019342:Acetic Acid