Preparation Of Modified Carbon Black-PTFE Cathode And Treatment Of Dye Wastewater By A New Two-Chamber Electrochemical System

Facing the tremendous pressure of environment protection with the rapidlydevelopment of economy, the dyeing sewage is unmanageable due to its properties ofgreat quantity, high colority and poor biochemical purification. Conventional wastewatertreatment processes are inefficient for the removal of these types of toxic and hazardousdyes from wastewater. The Electro-Fenton process as one of the powerful andenvironmental-friendly emerging technologies has been attracted much attention.In this research, a modified carbon black-PTFE cathode for the electrogeneration ofhydrogen peroxide was fabricated using modified carbon black powder as the catalyst andPTFE as the binder. Solution pH and methode of cathode modification have been studiedusing the electrolysis system fed with air at2L·min-1in Na₂SO₄solution of0.05M andthe characteristics of the cathode were examined by FTIR and BET. The experimentalresults show that: the optimum dose of3-Trifluoromethylaniline is0.05mM·g^-1in themodified methods, The extra H₂O₂generation rate reaches5.5mg·L-1·h-1·cm^-2after150min of electrolysis, and the current efficiency is91.0%at pH3and the current density of20mA·cm^-2.The experiment with the peroxi-coagulation system has been carried out to discussthe potential applications of wastewater treatment use the cathode. The effect of solutionpH and current density has been studied to the degradation of100mg·L-1of ARS in atwo-electrode undivided system. The result show that: more than90%of TOC of ARS hasbeen removed in150min at pH3and the current density is1.35mA·cm^-2.A new two-chamber electrochemical system has been developed to degradate organictoxic dye wastewater in this paper. To investigate the decolorization and mineralizationrate in the anode chamber, Fe²⁺supply dosage and supply rate, ratio of H₂O₂to Fe²⁺weredetermined to test and to validate a kinetic model for the reaction. The results showed that:the reaction effect is much better with the faster supply rate of the same amount of Fe²⁺. Inthe optimum operation conditions of [Fe²⁺]:[H₂O₂]=1:20, the removal rate of TOC of ARSis95.8%with the solar radiation, which is53.6%higher than that without the solarradiation, and the decolourization efficiency is more than99%in10min. Kinetic resultsshowed evidence of pseudo-first-order model. The final color removal efficiencies are 0.69%,53.8%,82.1%and98.5%by using the electrolysis, Fenton, electro-Fenton andphotoelectro-Fenton processes, respectively.