| With the rapid development of social economy since the reform and opening up in China,industrial and agricultural production a serious threat to the environment. Biodegradableorganic waste water is a difficult point in the field of water treatment, achieve a kind of highefficiency and low cost of biodegradable organic waste water treatment technology has beenthe environment researchers study goals. Caprolactam as raw materials for the production ofnylon in the process of production and use of all can produce high concentration organicwastewater, the treatment method is single and limited effect. Electrocatalytic oxidationtechnology for its efficient handling capacity of organic pollutants widely attention.Electrocatalytic electrode as the core part of the electrocatalytic oxidation technology, thematerial type and performance directly affects the processing effect. In many electric catalyticelectrodes, Ti/SnO2electrodes has good development prospect in wastewater treatmentbecause of the high oxidation ability, high oxygen evolution potential and the low cost.Ti/SnO2-Sb electrodes were preparated by Pechini method, the substrate was coated byimpregnation technology in the process of preparation. Main research contents include:(1)Effect of the number of electrode coating, the concentration of precursor solution, thecomplexing agent ratio in the precursor solution and the sintering temperature on catalyticoxidation of phenol performance and service life of Ti/SnO2-Sb electrode; effect of thedifferent Sb doping amount on coating material and performance of Ti/SnO2-Sb electrode.(2)Effect of the different Mo doping amount on surface morphology, chemical composition,coating structure, the oxygen evolution potential and the electrocatalytic oxidation of phenolof Ti/SnO2-Sb-Mo electrodes; by means of cyclic voltammograms, UV-Vis spectral opticaltesting method is combined with such as phenol, TOC and COD determination results of Modoping mechanism are analyzed.(3) Influence factors of electrocatalytic oxidationcaprolactam simulated wastewater and wastewater using Ti/SnO2-Sb-Mo electrode aselectrocatalytic anode.Above all the experimental study result and analysis, achieve the following conclusions:(1) The effect of the number of electrode coating, the concentration of precursor solution,the complexing agent ratio in the precursor solution and the sintering temperature on catalyticoxidation of phenol performance and service life of Ti/SnO2-Sb electrodes were not obvious. that’s mainly because of the the same electrode coating material. The conditions There is agreat influenceon on the stability and service life time of Ti/SnO2-Sb electrodes. A moderateamount of Sb doping would helpful to improve the electrocatalytic activity and stability of theTi/SnO2-Sb electrodes, Sb doping decrease the oxygen evolution potential of all dopingTi/SnO2electrodes. The performance of3%Sb doped Ti/SnO2-Sb electrode was the best.Optimal condition of preparation of Ti/SnO2-Sb electrode as follows: the number of electrodecoating was15, concentration of precursor solution was0.5mol/L, the mole ratio of metalions in liquid, citric acid, ethylene glycol was1:3:3, sintering temperature for using ladderprogram temperature to600℃, Sb doping was3%(set Sn as100%).(2) The clustering phenomena was discovered on Mo doping electrodes surface, Sbcontent in the coating was higher than the theoretical value and Mo content is lower than thetheoretical value, Mo and Sb doping dosen’t changed SnO2sifang rutile phase structure andinterstitial or instead into SnO2lattice. Ti/SnO2-Sb-Mo electrode with1%Mo presented thehighest electroactivity of phenol, the mineralization current efficiency, and the longer servicelife time. Ti/SnO2-Sb-Mo electrode with7%Mo possess the highest oxygen evolutionpotential. Mo doping improve Ti/SnO2-Sb-Mo electrodes mineralized performance were notobvious, the high Mo doping level will decrease the electrode performance. Mo auxiliaryTi/SnO2-Sb-Mo electrode adsorption phenol in the process of the electrocatalytic oxidationof phenol, too much Mo doping hinder the diffusion of water molecules to generate·OH onSb-set.(3) Set the preparated Ti/SnO2-Sb-Mo electrode as anode, the caprolactam simulatedwastewater was treated in the effective area40cm2, the spacing between adjacent electrodewas20mm, caprolactam initial concentration was100mg/L, the pH value was7, Na2SO4concentration was0.25mol/L, current density was20mA/cm2, after3.5h under the abovecondition of electrocatalytic oxidation treatment, COD removal rate was91.5%; Actualcaprolactam wastewater in the same reaction and the caprolactam wastewater was diluted20times, pH value was7, Na2SO4concentration was20g/L, current density was50mA/cm2,electrocatalytic oxidation treatment for3.5h the COD removal rate was33.2%under theabove condition. |
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