title: Continuous electrochemical treatment of phenolic wastewater in a tubular reactor.
abstract: The electrochemical treatment of phenolic wastewater in a continuous tubular reactor, constructed from a stainless steel tube with a cylindrical carbon anode at the centre, was investigated in this study, being first in literature. The effects of residence time on phenol removal was studied at 25 degrees C, 120 g l(-1) electrolyte concentration for 450 and 3100 mg l(-1) phenol feed concentrations with 61.4 and 54.7 mA cm(-2) current densities, respectively. The change in phenol concentration and pH of the reaction medium was monitored in every run and GC/MS analyses were performed to determine the fate of intermediate products formed during the electrochemical reaction in a specified batch run. During the electrolysis mono, di- and tri-substituted chlorinated phenol products were initially formed and consumed along with phenol thereafter mainly by polymerization mechanism. For 10 and 20 min of residence time phenol removal was 56% and 78%, respectively, with 450 mg l(-1) phenol feed concentration and above 40 min of residence time all phenol was consumed within the column. For 1, 1.5, 2 and 3h of residence time, phenol removal achieved was 42%, 71%, 81% and 98%, respectively, at 3100 mg l(-1) phenol feed concentration. It is noteworthy that more than 95% of the initial phenol was converted into a non-passivating polymer without hazardous end products in a comparatively fast and energy-efficient process, being a safe treatment.
authors.affiliation: Faculty of Engineering, Chemical Engineering Department, Hacettepe University, Beytepe 06532, Ankara, Turkey.
authors.forename: Bahadir K
authors.initials: BK
authors.lastname: Körbahti
authors.forename: Abdurrahman
authors.initials: A
authors.lastname: Tanyolaç
mesh_terms: D004202:Disinfectants / Q000737:chemistry* / Q000302:isolation & purification; D004563:Electrochemistry; D004784:Environmental Monitoring; D007700:Kinetics; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification; D011108:Polymers; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D004202:Disinfectants; D010636:Phenols; D011108:Polymers; D014874:Water Pollutants, Chemical