Electrochemical Removal Of Sulfur Ions In The Solution

Sulfide is often found in the petroleum, the natural gas and the related products, or waste gases and water. Not only is sulfide bad for human health and the ecological environment, but also lead to corrosion of the metal equipment. Therefore, it seems to be particularly necessary to adopt a high effective desulfurization method that is economical and environmental.There are some disadvantages by using conventional removal methods, such as adsorption and absorption, for the high sulfide content of wastewater, waste, oil, natural gas and related products, especially for the desulfurization process which has been designed and installed and put into useing. Physical methods required transformation process equipment or upgrade, the relative investment is large and there will be a tremendous impact on the production. Chemical methods may lead to some changes of physical and chemical properties of the product by adding a large number of chemical reagentsElectrochemical desulfurization is a new method of removal technology which using oxidation-reduction reaction of hydrogen sulfide or sulfur dioxide on the surface of electrode. It has many advantages such as high efficiency, simple operation, easy to automate, does not cause secondary pollution to the environment and so on. It also has very broad development prospects. At present the research on it is less at home, also have not to achieve industrialization, in view of the merits of electrochemical desulfurization. In this paper it chooses cyclic voltammetry and constant potential polarization method to research the electrochemical desulfurization mechanism in three-electrode system, and also studies the influence of environmental factors on desulfurization efficiency, such as electrolytic voltage, electrolytic time, electrolytic temperature, etc., Through the above research it can easily get the optimal conditions of the removal sulfide in the sulfide solution by electrochemical oxidation.The result of cyclic voltammetry show that sulfur ions have two electrochemical reaction processes on the carbon electrodes in1.Omol/L sodium hydroxide solution. First sulfide ion oxidize to sulfur which deposited on the electrode surface in-100mV, the reversibility of this reaction is stronger and the control step is sulfur ion diffusion. Sulfur elemental oxidize to sulfate ion in300mV.Experiments of the electrochemical desulfurization efficiency show that:as the electrolysis voltage, electrolytic time and temperature increases, the desulfurization efficiency showed a trend of first increase and then leveled off or slightly decreases. The suitable conditions of sulfide ion oxidize to sulfate ion in1.Omol/L sodium hydroxide solution electrolytic system is:electrolytic voltage is1.25V, electrolytic time is2400s, electrolytic temperature is333K. On the above conditions, the desulfurization efficiency can reach to more than of99.0%in0.1mol/L of sulfur solution can.