Experimental Study On The Electrochemical Oxidation Degradation Of Phenols Organic Pollutants

With the development of modern industry and economy, water pollution has already become an austere issue which baffles society of continuable development. At present, it has been the difficutlty and focus of the waste treatment for disposal of toxic and biorefractory organics which can't be treated effectively by the current ordinary waste water treatment technology. In this article, based on the research and development of treatment method of phenolic organic waste water, the studies on waste water select 4-chlorophenol as simulating organic is selected and the corresponding electro-oxidation degradation behaviors and characteristics are investigated. And we will develop the fundamental study on the electro-oxidation technology for the organics waste water treatment .This paper selects stainless steel as a matrix, first electroplatesα-PbO₂ as diamond made by electro-dip process, then electroplatesβ-PbO₂ doping NaF as suface layer. In electroplating system suface layer, using orthogonal experiment investigation temperature, current density and the quality of the NaF concentration affect on PbO₂ electrode oxidation degradation 4-CP's electricity catalytic activity. Finally arrive at the best conditions of electroplating PbO₂ electrode: the temperature is 70℃, current density is 15mA/cm-2, the quality of the NaF concentration is 1.26g/L-1. And the factor analysis obtains the current density's effection is the biggest, the NaF concentration is subordinate, and the influence of the temperature is the smallest. And further, which is prepared for additional experiment with higher electricity catalytic activity of stainless steel base PbO₂ electrode.By using the primitive PbO₂ electrode as anode, and regardes the stainless steel as cathode to degrade stimulant 4-chlorophenol waste water in a no dissepimental electrochemical reactor which is cylindrical and self-made by plexiglass. The factors such as applied voltage, pH, support electrolytes concentration, aeration rate, and initial pollutants concentration are the systematic and comprehensive research in the process of degrading the pollutants. The results of experimental show that when the initial pollutants concentration is 100 mg/L, the removal rate will be increased as the increasing of applied voltage; the suitable condition is 10 V. The optimal conditions of electrolyte concentration and aeration rate are 0.04mol/L and 0.2m3·h-1 respectively, the removal rate of 4-CP is the best. The degrading of pollutions is more effected by wastewater initial pH. In acidic condition, the removal rate of 4-CP enhanced obviously, but not little is better, when the pH is 3, the removal rate of 4-CP is the highest. Pollution wiping off ratio is decreased as increasing the initial pollution concentration, but the absolute wiping off value is increased wholly.The kinetcs study of pollutions electro-oxidaiton indicates that the electrolytic oxidation accords with the apparent first-order kinetics law. Simultaneously studies the oxidation rate constant impacted by the factors such as applied voltage, pH and initial pollutants concentration. The results indicate that the oxidation rate constant is firstly increased and then decreased as the increasing of the support electrolytes concentration and aeration rate, influenced by the pH obviously. The oxidation rare constant has linear relationship with the applied voltage. With the compare of different pollutions degrading by electro-oxidation, the pollutions'structure has influenced on the degradation . Suction electronic base makes compounds'reactivity reduce, electronic base makes compounds'reactivity enhance. For different replaced groups of degradationg from easy to difficult order is: -NH₂>-CH₃>-Cl>-NO₂.This article research indicate that the electro-chemistry oxidation process can effective degradation the 4-chlorophenol in the wastewater, and has a better stability. It can offer the theoretical foundation for the electro-chemical oxidation degrading the refractory organics, lay a foundation for the electro-chemical oxidation process during the practical.