Student Of Electrogeneration Of H₂O₂and Treatment Of Dye Wastewater On Acetylene Black-PTFE Composite Cathode

With the rapid development of industrial and agricultural, water pollution problemscontinue to emerge. The traditional biophysical methods showed some limitations indealing with refractory organic wastewater. Advanced oxidation technology graduallygoes into people’s vision for its superior oxidation. Electric Fenton as a typical advancedoxidation technology, for its high oxidation activity, no secondary pollution and simpleequipment become more and more popular.In this paper, we designed a composite cathode as a gas diffusion electrode forgenerating the hydrogen peroxide, thus to avoid the unnecessary waste duringtransportation and storage. A composite acetylene black-PTFE cathode consisting of aactive core that mainly provides catalytic activity to the composite cathode and adampproof coating that mainly brings about hydrophile-hydrophobe balance on thecomposite cathode surfaces has been fabricated. The main factors affecting the H2O2yieldand useful life of the composite cathode were investigated using a three-electrodeundivided cell fed with air at2L·min1in Na2SO4solution of0.05mol·L-1. Theexperimental results showed that:(1) the dampproof coating could increase the H2O2yieldand only when the cathode surfaces were at hydrophile–hydrophobe balance the H2O2yield was highest;(2) the dampproof coating could greatly increase the current carryingcapacity of the composite cathode, the optimal current density of108mA·cm2being4.5times higher than that of the cathode without dampproof coating (only the active core) andat108mA·cm2and pH3through150min electrolysis, an average H2O2generation rateof271mg·L1·h1·cm2was obtained, being the maximum obtained so far with an averagecurrent efficiency of79.1%and energy consumption of27.5kWh·kg–1(3) theelectrowetting resulted in the failure of the cathode without dampproof coating (only theactive core), the dampproof coating could greatly increase cathodic useful life.This paper also studied an electricity Fenton system that consist of a compositeacetylene black-PTFE cathode, a platinum anode, and a certain amount of Fe2+fordegrading acid magenta dye wastewater of100mg·L-1. The results show: after60minutes of electrolytic, by the addition of0.5mmol·L-1of Fe2+, the degradation rate of acidmagenta at absorption peak540nm reached99.1%. Moreover, the article also adoptanother electricity Fenton system that consist of a composite acetylene black-PTFEcathode and an iron anode to treatment mixed dye wastewater of50mg·L-1of acidmagenta and50mg·L-1Alizarin red S. After60minutes of electrolytic, the degradationrate of acid magenta at absorption peak at540nm reached97.6%, the degradation rate ofAlizarin red S at absorption peak at420nm reached98.3%. Degradation effect is veryobvious.