RESUMO
In the presence of silver ion, Mn2+ could be electro-oxidized to potassium hypermanganate in phosphoric acid solution, which could effectively react with pyrocatechol in acid solution and luminol in sodium hydroxide solution to produce chemiluminescence. On the basis of this, a novel indirect approach for the detection of Mn2+ was established. The effect of silver ions on the electrochemical oxidation of Mn2+was studied. when 1. 5 ×10-5 mol/L Ag+ and 0. 01 mol/L phosphoric acid solution were used in the process of electrochemical oxidation, the CL intensity could be up to the maximum value after the above solution was electrolyzed for 2 min. The relation of CL intensity and Mn2+concentration in the solutions at different pH and the selectivity were also investigated. when the pyrocatechol was used as luminescent reagent in the acidic medium, the CL intensity was linearly to the Mn2+concentration in the range of 1. 82×10-7-7. 27×10-5 mol/L with excellent selectivity. Common ions had little interferences in the determination of Mn2+. The method was successfully applied to the determination of Mn2+ in surface water and drinking water with satisfactory results.
RESUMO
Con la creciente presión hacia un uso más racional del recurso hídrico, el desarrollo de tecnologías apropiadas de tratamiento de aguas es cada vez más urgente. Debido a ello, en los últimos años se han propuesto procesos de oxidación fotoquímicos y electroquímicos como alternativa para el tratamiento de aguas contaminadas con sustancias antropogénicas difícilmente biodegradables, así como para eliminar bacterias en aguas destinadas al consumo humano. El objetivo de este trabajo es presentar algunas de nuestras más recientes investigaciones que demuestran que tanto la electroquímica como la fotoquímica, al igual que el acople de estos procesos con tratamientos biológicos, son alternativas muy prometedoras para aumentar la calidad del agua.
With the increasing pressure on a more effective use of water resources, the developpement of appropriate water treatment technologies become more and more important. Photochemical and electrochemical oxidation processes have been proposed in recent years as an attractive alternative for the treatment of contaminated water containing anthropogenic substances hardly biodegradable as well as to purify and disinfect drinking waters. The aim of this paper is to present some of our last results demonstrating that electrochemical, photochemical, and the coupling of these processes with biological systems are very promising alternativesfor the improvement of the water quality.