Degradation of organic pollutants in aquatic environment photoinduced by Fe(III)Cit complex: Impact of TiO2

0359748 - ÚFCH JH 2012 RIV NL eng J - Journal Article
Kolář, Michal - Jirkovský, Jaromír - Mailhot, G. - Bolte, M. - Krýsa, J.
Degradation of organic pollutants in aquatic environment photoinduced by Fe(III)Cit complex: Impact of TiO2.
Catalysis Today. Roč. 161, č. 1 (2011), s. 127-132. ISSN 0920-5861. E-ISSN 1873-4308
R&D Projects: GA MŠMT 1M0577
Institutional research plan: CEZ:AV0Z40400503
Keywords : ferric citrate * TiO2 * monuron
Subject RIV: CG - Electrochemistry
Impact factor: 3.407, year: 2011

Kinetics of photoinduced degradation of monuron (N-(4-chlorophenyl)-N',N'-dimethylurea) in three different photocatalytic systems (Fe(III)Cit, TiO2, combined system Fe(III)Cit + TiO2) were studied and compared. Principal importance of pH on the efficiency of the systems containing ferric citrate was found (optimal pH near 3). Positive effect of TiO2 addition (24 mg L-1) to Fe(III)Cit (2.55 x 10(-4) mol L-1) was observed at the optimal pH. This effect was emphasized with tenfold lower concentration of Fe(III) Cit (2.55 x 10(-5) mol L-1). On the contrary, the reaction was practically inhibited close to neutral pH. At acid pH, more active species of both Fe(III) Cit and Fe(III) aquacomplexes are present. During photolysis of the Fe(III) Cit complex, a proton is consumed, restoring hydroxyl group; if the pH approaches the neutral zone, the Fe(III) tends to form aggregates, which are far less photoactive.
Permanent Link: http://hdl.handle.net/11104/0197470