The Studay Of Three Kinds Of Electrochemical Technologies In The Water Treatment

Electrochemical technology is a series of process which includs chemical reaction, electrochemical reaction or physical reaction by a extra electric field in a 'specifically chemical reactor to get anticipaitive purpose about removing contamination in wastewater or reclaiming some usefull substances. In this paper, the different woring electrode materials were used to dispose liquid waste containing Chrome(VI), simulated methyl orange wastewater and nitrate water and the satisfactory results were obtained.This paper were composed of tree sections as follows:(1) TiO2loaded on Activated Carbon Fiber was prepared by sol-gel method, and whose micrograph surface was characterized by SEM. The operating parameters were investigated including electrosorption time, solution pH, electrosorption potential and the contentration of Chrome(VI). Experimental results showed that the electrode of ACF-TiO2has a good electroadsorption capacity. The concentration of the waste water containing Chrome(VI) was25mg/L, when the electrolysis potential was1.5V, the initial pH was3.0, the electrolyzing time was150min, the electroadsorption rate of Chrome(VI) was up to98%. The electroadsorption of Chrome(VI) follows Langmuir adsorption isotherm equation and pseudo-second-order kinetic equation.(2) The methyl orange degradation was carried out by the electro-Fenton reaction which was composed of graphite anode and active carbon fiber cathode. Factors on degradation of methyl orange was investigated such as electrolysis time,solution pH, electrolysis potential, the contentration of Fe2+and the initial contentration of methyl orange. The results showed that the ACF cathode had better electrooxidation performance and the concentration of methyl orange was4mmol/L, when the voltage was8V, the contentration of Fe2+was0.2mmol/L, the pH of the methyl orange water was3and the the electrolyzing time was60min,the color removal efficiency was up to98.12%and the COD elimination was50.89%. Through ultraviolet spectrum analysis, the—N=N—double conjugate of methyl orange was destroyed firstly and then benzene ring was crakcked, lastly almost all the molecules had been degraded to CO2and water by sonoelectrochemical. The kinetic analysis showed that the decolorization and COD elimination of methyl orange degradation follow first-order kinetics relationship.(3)Chronoamperometry was used to investigate the conditions of electrochemical reduction system by bismuth cathode and stainless steel anodes on removing nitrate wastewater. The different electrolysis potential and nitrate contentration was used to investigat the electrochemical reduction effciency. The results obtioned under the optimal operational parameters:0.1mol/L NaSO4of pH12containing100mg/L nitrate the potential at-2.1V vs.Ag/AgCl showed that removal rate65.23%and the selectivity of nitrogen56.78%. Experimental results showed that the bismuth cathode had better electrocatayvtic selectivity performance and pseudo-first-order reaction was used for the electrochemical reduction of nitrate.