Laboratory Experiments on Electrochemical Remediation of the Environment. Part 5: Indirect H2S Remediation

• J. G. Ibanez ^[1]
  1. [1] Universidad Iberoamericana

     Universidad Iberoamericana

     México

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 78, Nº 6, 2001, pág. 778
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Many polluting gases can be transformed to nonpolluting--or at least, less polluting--forms by changing the oxidation states of one or more of their constituent atoms. This can often be achieved by transferring electrons to or from the pollutant from or to an electrified interface. Since electrochemical remediation methods require an ion-conducting medium to perform their function, this can be accomplished either by using an absorption medium in an electrochemical cell (inner-cell process) or by absorbing the gas first and then transferring the absorption medium into the electrochemical cell to be treated (outer-cell process). Also, in such methods the polluting species can either undergo electron transfer on an electrode surface (direct method), or electrons can be shuttled to or from the electrode by an electron carrier (indirect method). We report here an experiment to demonstrate one way in which the electrochemical treatment of H2S can be accomplished by bubbling it through an iodine solution. A dramatic change in color occurs, due to the oxidation of S2- ions by I2, producing a suspension of yellow elemental S and colorless iodide ions. The resulting solution is then electrolyzed, regenerating the iodine and producing pure hydrogen. This cycle can be repeated many times with the same solution.