The Measurement And Treatment Of Sulfide In Waste Water With Electrochemical Method

Sulfide is the main pollutant in the wastewater of some chemical industries. Sulfide ions (S2^2-) not only erode metals but also disserve life-form. Therefore, it is important to make accurate measurement and valid treatment on sulfide. In this dissertation, the sulfide in industrial wastewater is taken as the object of study. Firstly, in order to measure sulfide accurately, the measurement method with coated wire Ag -Ag2S electrode is put forward. Secondly, the wastewater is treated with indirect electrolytic method, its possibility is verified by the theories and actual experiments.The preparation method of coated wire Ag - Ag2S electrode is introduced, whose electrochemical performance is tested in the same time. The result indicates that the coated wire Ag - Ag2S electrode has the equal anti - oxidation property with the fixing membrane sulfide selective electrode. The solid antimony electrode and iridium electrode serve as reference electrode in this experiment, because of the elimination of liquid abutting potential, the measurement is improved, and the linear scope of electrode is extended obviously. The effect of some kinds of surfactants is tested. It has been shownthat some cationic surfactant and anionic surfactant have positive effect on measurement, with dosage of CMC, the respond linear scope is extended obviously, too. Prepare the standard sulfide solution with thioacetamide for the first time, this kind of standard solution doesn't influence the measurement, and it is very steady. In experiments, the mathematics model about electric kinetic potential E, temperature T and density cs2- is set up. This model reflects the function relation of electric kinetic potential E corresponding with temperature T and density cs2- objectively and completely in the actual sulfide measurement.The wastewater that contains sulfide is electrolyzed with the stainless steel served as cathode, anode materials. The trough voltage, electrode area, space between electrodes, dosage of electrolyte and initial pH are chose, the practical electrolysis terms are acquired. The varieties of density, pH value, electrolysis electric current in the electrolysis process and the effects of initial sulfide density, temperature on electrolysis are studied. Experiments prove that the treating technology with electrolytic method runs stably, operates simply and the cost is low. Moreover, the wastewater can be used for the second time after treatment, which economizes water resources.In this experiment, the actual waste water is measured and treated, the recovery rate is 99% 101%,the elimination rate is above 99%,the result is satisfying.