Study On Preparation Of PbO₂/CF Electrode And Its Property

With the expanding scale of industrialization production of pesticide,cyanide leaching of gold and so on,the difficulty of sewage disposal is incremental and substandard sewage discharge will be environmentally hazardous.According to the characteristic that sewage is refractory and low biochemical quality,An advanced oxidation technology was adopted for the pretreatment degradation of sewage in this thesis.A new electrode material called carbon fiber was introduced and its electrochemical and electro-catalytic performance was investigated.A lead dioxide electrode was prepared using carbon fiber as basal body.Depending on the methods such as X-ray diffraction,SEM,polarization curve,the shape,ingredients,catalytic property and service lifetime of the lead dioxide active layer on the surface of the electrode were characterized and the impact of the electroplating conditions upon the factors was studied also.With the prepared electrode,the electrochemical catalytic degradation of m-dicyanobenzene sewage was carried out and this thesis analyzed the influence of ampere density,pH upon the degradation effect during the reaction process.Eventually,the method of the combination of electrochemical pretreatment and A/O technics was used to dispose the process sewage of a chemical factory and the study of the technics was researched in this paper.The use of anode polarization curve characterized that the oxygen-evolution potent-ial in the acid solution of carbon fiber was 1.82V and the removal rate reached 82.2 % when the process of m-dicyanobenzene sewage electrolyzation sustained 1h.During t he electrolyzation process,the electrode polarization effect was tininess and the voltage and the electric current remained stable,which indicated that the carbon fiber electrode possessed favorable electro-catalytic and electro-catalytic performance.The method of e lectrodeposition process was used to prepare the lead dioxide electrode with carbon fib er as basal body. The best technological conditions of study electroplating process wer-e as follows:plumbi nitras solution concentration 150g/L,pH around 1.2,NaF additiveO. 5g/L,distance between plates 1.5cm,temperature 60℃,ampere density 40mA/cm2,Elec-tro plating time 2h.The performance of the prepared electrode under the best technolog-ica 1 conditions was characterized as the crystal pattern on the surface of the electrode,de pending on the use of XRD.β-PbO2 was the main acquisition on the electrode surfa-ce and SEM showed that the crystal pattern of the electrode was well-distributed and co mpact.Voltage-current curve and polarization curve showed that the prepared electro-de had a higher oxygen-evolution potential which was around 1.7V and indicated a g-oo d electrochemical performance.The influence of different ampere density,plate spacin-g,i nitial concentration of m-dicyanobenzene,pH value of the sewage,electrolyte concen-trati on and reaction time,upon the removal efficiency of m-dicyanobenzene were inves-tigat ed,during the electrochemical oxidation process of m-dicyanobenzene,using prepar-ed el ectrode.The method of the inosculation of electrochemical pretreatment and A/O techni cs was used to dispose the m-dicyanobenzene sewage.After electrochemical pretre-atme nt disposal,the B/C of the sewage increased to 0.55 and with additional A/O technics disposing,the degradation rate of m-dicyanobenzene,COD,NH4+ -N,was 100%,98%and 85 %,respectively.