Study on wet air oxidation of aqueous ferrous cyanide solution catalyzed by three metal salts

• Published in: Water Science & Technology Vol. 42; no. 3-4; pp. 131 - 136
• Main Authors: LEE, B.-N, LOU, J.-C
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Pergamon Press 01-01-2000; IWA Publishing
• Subjects: Applied sciences; Catalysis; Catalysts; Chemical oxygen demand; Copper; Cyanides; Exact sciences and technology; Ferrocyanide; Industrial wastewaters; Iron; Kinetics; Metals; Oxidation; Oxidation rate; Pollution; Reaction kinetics; Reaction time; Removal; Salts; Wastewaters; Water treatment and pollution; Wet oxidation; Wet oxidation process; Iron II Cyanides; Cerium Nitrates; Temperature effect; Experimental study; Manganese Nitrates; Copper Sulfates; Chemical oxygen demand; Industrial waste water; Wet air; Physicochemical purification; Oxidation; Waste water purification; Catalyst
• ISBN: 1900222442; 9781900222440
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2000.0369

The catalytic wet oxidation (CWO) process with Cu super(2+), Mn super(2+), and Ce super(2+) as catalysts, respectively, was applied to investigate the degradation of ferrocyanide (Fe(CN) sub(6) super(4-)) solution. For the conversions of Fe(CN) super(64) during the noncatalytic wet oxidation (WO) process up to 99.9% was attained after a reaction time of 70 min. The COD removal efficiency was observed as only 38% in a noncatalytic oxidation; however, it could be enhanced to 75%, 61%, and 50% in the presence of Cu super(2+), Mn super(2+), and Ce super(2+), respectively. Both noncatalytic and catalytic wet oxidation processes of Fe(CN) sub(6) super(4-) solution were considered to be a two-step reaction at pH 9.0 and temperatures of 433-473 K. The oxidation rate was initially fast, followed by a slow step, which did obey first-order kinetics with respect to chemical oxygen demand (COD). Both the Cu super(2+) and Ce super(2+) catalyzed oxidation showed a significant effect on the reduction of activation energy during the first reaction of the WO runs.