title: Electrochemical degradation of m-cresol using porous carbon-nanotube-containing cathode and Ti/SnO2-Sb2O5-IrO2 anode: kinetics, byproducts and biodegradability.
abstract: The degradation of m-cresol solution was studied using an electrochemical oxidation system with Ti/SnO2-Sb2O5-IrO2 anode for anodic oxidation and porous carbon-nanotube-containing cathode for H2O2 electrogeneration along with Fe(3+) reduction. Organic pollutants were oxidized by hydroxyl radical (OH) formed simultaneously in the medium from electro-Fenton reaction in the presence of Fe(2+) and at the anode surface from water oxidation. The porous cathode made of graphite, carbon nanotube (CNT) and polytetrafluoroethene (PTFE) exhibited a higher catalytic activity toward O2 reduction producing H2O2 and Fe(3+) reduction for Fe(2+) regeneration, favoring organics degradation by electro-Fenton oxidation. The degradation kinetics results revealed that the reaction of m-cresol cleavage with hydroxyl radicals could be described by pseudo first-order kinetics. The progress of organics mineralization demonstrated some byproducts were formed during m-cresol degradation. Based on the byproducts identified by GC-MS and HPLC, the sequential process of m-cresol degradation was proposed. Furthermore, the aerobic biological treatment showed that the electrochemical treatment was able to evidently enhance the biodegradability of m-cresol solution.
authors.affiliation: School of Environment and Safety Engineering, Qingdao University of Science and Technology, Shandong, Qingdao 266042, China. cyyf200611@qust.edu.cn
authors.forename: Yanyang
authors.initials: Y
authors.lastname: Chu
authors.forename: Dongmei
authors.initials: D
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Qian
authors.forename: Lingling
authors.initials: L
authors.lastname: Li
mesh_terms: D000332:Aerobiosis; D000965:Antimony / Q000737:chemistry*; D001673:Biodegradation, Environmental; D003408:Cresols / Q000737:chemistry* / Q000378:metabolism; D004566:Electrodes; D004572:Electrolysis; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry*; D016062:Porosity; D012722:Sewage; D017971:Tin Compounds / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003408:Cresols; D037742:Nanotubes, Carbon; D012722:Sewage; D017971:Tin Compounds; D014874:Water Pollutants, Chemical; C044458:iridium oxide; C032538:4-cresol; D007495:Iridium; C027104:antimony pentoxide; D000965:Antimony; D006861:Hydrogen Peroxide; D007501:Iron; C045358:stannic oxide