The photocatalytic degradation of the herbicide atrazine has been studied using suspended titanium
dioxide as catalyst. The Langmuir-Hinshelwood model is satisfactorily obeyed at initial time and in the
course of the reaction. The rate of degradation is found to be enhanced by the addition of persulphate ions.
Competitive degradation between atrazine and other pollutants is satisfactorily interpreted as monitored by
a competitive adsorption of the reactants. As a consequence, efficient reactants such as salicylic acid and
phenol delay atrazine degradation until these compounds are degraded.

O.  Zahraa

L.  Sauvanaud

G.  Hamard

M.  Bouchy

Kinetics of atrazine degradation by photocatalytic process in aqueous solution

Experimental research of photocatalytical oxidation (PCO) of aqueous solutions of de-icing
agents (ethylene glycol and ethylene glycol monoethyl ether) and methyl <i>tert</i>-butyl ether (MTBE) was undertaken.
These chemicals are water-soluble components of jet and motor fuels accidentally disposed to
the environment. Titanium dioxide (Degussa P25) under near-UV irradiation was selected as a photocatalyst.
A slightly acidic medium was preferable for the process efficiency for MTBE, whereas a neutral medium
was beneficial for de-icing agents and jet fuel aqueous extracts. <mml:math alttext="${\text{TiO}}_{\text{2}} $" id="E1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> suspension fractional composition was found to be dependent on pH and the presence of organic admixtures: the minimum size of <mml:math alttext="${\text{TiO}}_{\text{2}} $" id="E2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> particles at their maximum uniformity was established in an acidic medium, where the efficiency of PCO of
de-icing agents was the poorest. On the other hand, neutral and slightly acidic media, beneficial for PCO efficiency,
were favourable for particle agglomeration, which indicates a minimal role for photocatalyst particle
size in PCO efficiency. PCO efficiency increased with increasing MTBE and icing inhibitor concentration. The
biodegradability of aqueous solutions of oxygenated additives increased as PCO proceeded. The influence
of mineral additives—sulphate, calcium, ferric and manganese ions—on the process efficiency was found to
be complex. Special attention was paid to energy-saving PCO with a photocatalyst attached to buoyant glass
micro-spheres and reduced intensity of stirring of the slurry.

M. Krichevskaya

A. Kachina

T. Malygina

S. Preis

J. Kallas

Photocatalytic oxidation of fuel oxygenated additives in aqueous solutions

In this study humic acids, which are known to be a heterogeneous group of organic macromolecules
found in natural waters, were oxidized using ozonation and photocatalysis in a sequential system.
Ozonation was employed for achieving partial oxidation of humic acids prior to photocatalytic oxidation.
Degradation of humic acid was explained by using pseudo first order reaction rate model based on UV-vis
measurements. An improvement was achieved in the photocatalytic degradation rates with respect to the
degree of pre-oxidation by ozonation. Due to the surface oriented nature of photocatalysis, adsorption characteristics
of partially oxidized humic acid samples on <mml:math alttext="${\text{TiO}}_{\text{2}} $" id="E1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> photocatalyst were evaluated by the application
of the Freundlich adsorption model. The photocatalytic degradation rates did not correlate well with the
dark adsorption characteristics of the pre-ozonated as well as untreated humic acid samples.

Aslihan Kerc

Miray Bekbolet

Ahmet Mete Saatci

Effect of partial oxidation by ozonation on the photocatalytic degradation of humic acids

Aims of the present work are to investigate the photomineralization of commercial humic acid
in water solution.The effect of initial pH of solution and different anions (chloride, sulfate and mixture)
on the photocatalytic degradation of HA with titanium dioxide in aqueous solution has been examined.
The photocatalytic mineralization rate in alkaline solution is lower than in neutral and acidic solution. In our
conditions no effect of chloride ions on the degradation rate is observed. The influence of the sulfate depends
on its concentration in the solution. For a large concentration, we note a decrease of the mineralization
rate.

Jarek Wiszniowski

Didier Robert

Joanna Surmacz-Gorska

Korneliusz Miksch

Jean-Victor Weber

Photocatalytic mineralization of humic acids with <svg style="vertical-align:-3.27605pt" height="15.675" version="1.1" viewBox="0 0 32.512501 15.675" width="32.512501" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.537)"><path id="x54" d="M592 498l-30 -3q-13 63 -31 89q-13 19 -33.5 25.5t-75.5 6.5h-70v-493q0 -60 16 -75.5t86 -19.5v-28h-286v28q68 4 83.5 19.5t15.5 75.5v493h-62q-60 0 -83 -7t-33 -24q-12 -17 -32 -90h-29q10 116 12 180h20q10 -16 21 -20.5t34 -4.5h395q19 0 28.5 5t21.5 20h21&#xA;q2 -89 11 -177z" /></g><g transform="matrix(.017,-0,0,-.017,8.868,11.537)"><path id="x69" d="M135 536q-20 0 -35 15.5t-15 35.5q0 22 15 37t36 15t35.5 -15t14.5 -37q0 -21 -15 -36t-36 -15zM252 0h-220v26q48 5 59 17t11 63v206q0 47 -9 58t-54 18v24q78 12 142 39v-345q0 -51 11.5 -63t59.5 -17v-26z" /></g><g transform="matrix(.017,-0,0,-.017,13.424,11.537)"><path id="x4F" d="M381 665q131 0 226.5 -93t95.5 -239q0 -158 -96 -253t-238 -95q-137 0 -231 95t-94 238q0 142 92.5 244.5t244.5 102.5zM359 629q-89 0 -151 -74.5t-62 -208.5q0 -141 69 -233t175 -92q90 0 150.5 74t60.5 211q0 152 -69 237.5t-173 85.5z" /></g><g transform="matrix(.012,-0,0,-.012,26.125,15.613)"><path id="x32" d="M412 140l28 -9q0 -2 -35 -131h-373v23q112 112 161 170q59 70 92 127t33 115q0 63 -31 98t-86 35q-75 0 -137 -93l-22 20l57 81q55 59 135 59q69 0 118.5 -46.5t49.5 -122.5q0 -62 -29.5 -114t-102.5 -130l-141 -149h186q42 0 58.5 10.5t38.5 56.5z" /></g></svg>: Effect of pH, sulfate and chloride anions

The photocatalytic degradation of aqueous solutions of Acid Orange 7 in <mml:math alttext="${\text{TiO}}_{\text{2}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> suspensions has been investigated with the use of a solar light simulating source. It has been found that, when the full
range of emitted photons is used, decolorization and complete mineralization of the solution is achieved
with satisfactory rates, depending on initial dye concentration. A reaction pathway is proposed according
to which degradation of the dye molecules adsorbed on the photocatalyst surface takes place via a series of
oxidation steps, which lead to decolorization and formation of a number of intermediates, mainly aromatic
and aliphatic acids, which are further oxidized toward compounds of progressively lower molecular weight.
Eventually, mineralization is achieved leading to the formation of gas phase <mml:math alttext="${\text{CO}}_{\text{2}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> and inorganic ions in solution.
Kinetic results show that the initial rate of decolorization depends strongly on surface coverage and on
incident photon energy. Visible light photons contribute to decolorization, via the photosensitization mechanism,
but with reaction rates which are more than two orders of magnitude lower than the corresponding
ones induced by photons of energy higher than that of the band gap of the semiconductor. In both cases,
the initial rate of decolorization is significantly reduced for dye coverages close to monolayer.

Maria  Stylidi

Dimitris I. Kondarides

Xenophon E. Verykios

Mechanistic and kinetic study of solar-light induced photocatalytic degradation of Acid Orange 7 in aqueous <svg style="vertical-align:-3.27605pt" height="15.675" version="1.1" viewBox="0 0 32.512501 15.675" width="32.512501" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.537)"><path id="x54" d="M592 498l-30 -3q-13 63 -31 89q-13 19 -33.5 25.5t-75.5 6.5h-70v-493q0 -60 16 -75.5t86 -19.5v-28h-286v28q68 4 83.5 19.5t15.5 75.5v493h-62q-60 0 -83 -7t-33 -24q-12 -17 -32 -90h-29q10 116 12 180h20q10 -16 21 -20.5t34 -4.5h395q19 0 28.5 5t21.5 20h21&#xA;q2 -89 11 -177z" /></g><g transform="matrix(.017,-0,0,-.017,8.868,11.537)"><path id="x69" d="M135 536q-20 0 -35 15.5t-15 35.5q0 22 15 37t36 15t35.5 -15t14.5 -37q0 -21 -15 -36t-36 -15zM252 0h-220v26q48 5 59 17t11 63v206q0 47 -9 58t-54 18v24q78 12 142 39v-345q0 -51 11.5 -63t59.5 -17v-26z" /></g><g transform="matrix(.017,-0,0,-.017,13.424,11.537)"><path id="x4F" d="M381 665q131 0 226.5 -93t95.5 -239q0 -158 -96 -253t-238 -95q-137 0 -231 95t-94 238q0 142 92.5 244.5t244.5 102.5zM359 629q-89 0 -151 -74.5t-62 -208.5q0 -141 69 -233t175 -92q90 0 150.5 74t60.5 211q0 152 -69 237.5t-173 85.5z" /></g><g transform="matrix(.012,-0,0,-.012,26.125,15.613)"><path id="x32" d="M412 140l28 -9q0 -2 -35 -131h-373v23q112 112 161 170q59 70 92 127t33 115q0 63 -31 98t-86 35q-75 0 -137 -93l-22 20l57 81q55 59 135 59q69 0 118.5 -46.5t49.5 -122.5q0 -62 -29.5 -114t-102.5 -130l-141 -149h186q42 0 58.5 10.5t38.5 56.5z" /></g></svg> suspensions

The photocatalytic degradation of two azo-dyes–an industrial one (Congo Red (CR)), and an
alimentary one (Amaranth (AM))–has been investigated in <mml:math alttext="${\text{TiO}}_{\text{2}} $" id="E1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math>/UV aqueous suspensions. In addition to a
prompt removal of the colors, <mml:math alttext="${\text{TiO}}_{\text{2}} $" id="E2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math>/UV-based photocatalysis was simultaneously able to fully oxidize the
dyes, with a complete mineralization of organic carbon into <mml:math alttext="${\text{CO}}_{\text{2}} $" id="E3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math>. In particular, the aromatic rings were submitted
to successive attacks by photogenerated <mml:math alttext="${\text{OH}}^ \circ  $" id="E4" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mtext>OH</mml:mtext></mml:mrow><mml:mo>∘</mml:mo></mml:msup></mml:mrow></mml:math> radicals leading to hydroxylated metabolites before the
ring opening and the final evolution of <mml:math alttext="${\text{CO}}_{\text{2}} $" id="E5" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> induced by repeated subsequent “photo-Kolbe” reactions with
carboxylic intermediates. Simultaneously, sulfur heteroatoms were converted into innocuous <mml:math alttext="${\text{SO}}_{\text{4}} x^{2 - } $" id="E6" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>SO</mml:mtext></mml:mrow><mml:mtext>4</mml:mtext></mml:msub><mml:mrow><mml:mn>2</mml:mn><mml:mo>−</mml:mo></mml:mrow></mml:mrow></mml:math> ions. The mineralization of nitrogen was more complex to analyze. Nitrogen atoms in the -3 oxidation state, such
as in the amino-groups of CR, initially remained at this reduction degree and produced <mml:math alttext="${\text{NH}}_{\text{4}}^ +  $" id="E7" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>NH</mml:mtext></mml:mrow><mml:mtext>4</mml:mtext></mml:msub><mml:mo>+</mml:mo></mml:mrow></mml:math> cations, subsequently and very slowly converted into <mml:math alttext="${\text{NO}}_{\text{3}}^{-} $" id="E8" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>NO</mml:mtext></mml:mrow><mml:mtext>3</mml:mtext></mml:msub><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:mrow></mml:math> anions. For both azo-dyes (CR and AM) degradation, the overall
mass balance in nitrogen was always found incomplete. Various experiments performed in pure oxygen in
a vacuum-tight cell and then in an air-free photoreactor (but filled with pure oxygen) enabled us to put in
evidence the formation of <mml:math alttext="${\text{N}}_{\text{2}} $" id="E9" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>N</mml:mtext><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math>. Quantitative measurements clearly indicated that gaseous dinitrogen evolved
stoichiometrically corresponded to the mineralization of the central –N=N– azo-group. This constitutes the
ideal issue for the elimination of nitrogen-containing pollutants, not only for environmental photocatalysis
but also for any other physicochemical method. These results suggest that <mml:math alttext="${\text{TiO}}_{\text{2}} $" id="E10" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math>/UV photocatalysis may be
envisaged as a method for treatment of diluted colored waste waters not only for decolorization but also for
total detoxification, in particular in textile industries in semi-arid countries.

E. Puzenat

H. Lachheb

M. Karkmaz

A. Houas

C. Guillard

J. M. Herrmann

Fate of nitrogen atoms in the photocatalytic degradation of industrial (congo red) and alimentary (amaranth) azo dyes. Evidence for mineralization into gaseous dinitrogen

This study examined the photocatalytic degradation of common textile dye, reactive yellow 17 by
photocatalysis over <mml:math alttext="${\text{TiO}}_{\text{2}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> (Degussa P25) photocatalyst coated on the glass plates (reactor) using cement as a
binder. Sunlight was used as an energy source. The degradation efficiency was found to be the high at around
neutral pH values. The influence of additives such as <mml:math alttext="${\text{H}}_{\text{2}} {\text{O}}_{\text{2}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>H</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math>, <mml:math alttext="${\text{K}}_{\text{2}} {\text{S}}_{\text{2}} {\text{O}}_{\text{8}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>K</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>S</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mtext>8</mml:mtext></mml:msub></mml:mrow></mml:math>, <mml:math alttext="${\text{Na}}_{\text{2}} {\text{CO}}_{\text{3}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Na</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mrow><mml:mtext>CO</mml:mtext></mml:mrow><mml:mtext>3</mml:mtext></mml:msub></mml:mrow></mml:math> or NaCl, on the degradation
efficiency of the dye in the presence of cement binder was systematically studied. Both <mml:math alttext="${\text{Na}}_{\text{2}} {\text{CO}}_{\text{3}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Na</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mrow><mml:mtext>CO</mml:mtext></mml:mrow><mml:mtext>3</mml:mtext></mml:msub></mml:mrow></mml:math> and NaCl
were hindering the rate of photocatalytic degradation. Whereas, increase the initial concentrations of both
<mml:math alttext="${\text{H}}_{\text{2}} {\text{O}}_{\text{2}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>H</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> and <mml:math alttext="${\text{K}}_{\text{2}} {\text{S}}_{\text{2}} {\text{O}}_{\text{8}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>K</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>S</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mtext>8</mml:mtext></mml:msub></mml:mrow></mml:math>, increased the rate of degradation of the dye. UV-vis spectrophotometer and chemical
oxidation demand were used to study decolourisation and degradation of dye, respectively. From this study,
degradation of textile dye reactive yellow 17 with <mml:math alttext="${\text{TiO}}_{\text{2}} $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>TiO</mml:mtext></mml:mrow><mml:mtext>2</mml:mtext></mml:msub></mml:mrow></mml:math> photocatalyst coated on the glass plate using cement
as a binder employing solar energy may emerge as a cost-effective method for textile dye wastewater of low
concentration.

B.  Neppolian

S. R. Kanel

H. C. Choi

M. V. Shankar

Banunathi  Arabindoo

V.  Murugesan

Photocatalytic degradation of reactive yellow 17 dye in aqueous solution in the presence of <svg style="vertical-align:-3.27605pt" height="15.675" version="1.1" viewBox="0 0 32.512501 15.675" width="32.512501" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.537)"><path id="x54" d="M592 498l-30 -3q-13 63 -31 89q-13 19 -33.5 25.5t-75.5 6.5h-70v-493q0 -60 16 -75.5t86 -19.5v-28h-286v28q68 4 83.5 19.5t15.5 75.5v493h-62q-60 0 -83 -7t-33 -24q-12 -17 -32 -90h-29q10 116 12 180h20q10 -16 21 -20.5t34 -4.5h395q19 0 28.5 5t21.5 20h21&#xA;q2 -89 11 -177z" /></g><g transform="matrix(.017,-0,0,-.017,8.868,11.537)"><path id="x69" d="M135 536q-20 0 -35 15.5t-15 35.5q0 22 15 37t36 15t35.5 -15t14.5 -37q0 -21 -15 -36t-36 -15zM252 0h-220v26q48 5 59 17t11 63v206q0 47 -9 58t-54 18v24q78 12 142 39v-345q0 -51 11.5 -63t59.5 -17v-26z" /></g><g transform="matrix(.017,-0,0,-.017,13.424,11.537)"><path id="x4F" d="M381 665q131 0 226.5 -93t95.5 -239q0 -158 -96 -253t-238 -95q-137 0 -231 95t-94 238q0 142 92.5 244.5t244.5 102.5zM359 629q-89 0 -151 -74.5t-62 -208.5q0 -141 69 -233t175 -92q90 0 150.5 74t60.5 211q0 152 -69 237.5t-173 85.5z" /></g><g transform="matrix(.012,-0,0,-.012,26.125,15.613)"><path id="x32" d="M412 140l28 -9q0 -2 -35 -131h-373v23q112 112 161 170q59 70 92 127t33 115q0 63 -31 98t-86 35q-75 0 -137 -93l-22 20l57 81q55 59 135 59q69 0 118.5 -46.5t49.5 -122.5q0 -62 -29.5 -114t-102.5 -130l-141 -149h186q42 0 58.5 10.5t38.5 56.5z" /></g></svg> with cement binder

M. S. A. Abdel-Mottaleb

Editorial

The Fe(III)-photoinduced degradation of <mml:math alttext="$4$" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>4</mml:mn><mml:mo></mml:mo></mml:msup></mml:math>,<mml:math alttext="$4'$" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>4</mml:mn><mml:mo>&#x2032;</mml:mo></mml:msup></mml:math>-diaminostilbene-<mml:math alttext="$2$" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>2</mml:mn><mml:mo></mml:mo></mml:msup></mml:math>,<mml:math alttext="$2'$" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>2</mml:mn><mml:mo>&#x2032;</mml:mo></mml:msup></mml:math>-disulfonic acid (DSD), used as a model compound of fluorescent whitening agents, was investigated in aqueous solution. The mixing
of DSD and iron(III) solutions immediately led to DSD degradation into two oxidation products 5-amino-2-
formyl-benzene sulfonic acid (<b>1</b>) and DSD epoxide (<b>2</b>) together with the formation of Fe(II). The behaviour
of the latter solution was investigated under monochromatic excitation at 365 nm. The irradiation of the
solution resulted in a photoredox process that yielded Fe(II) and <mml:math alttext="${\text{HO}}^ \bullet  $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mtext>HO</mml:mtext></mml:mrow><mml:mo>&#x2022;</mml:mo></mml:msup></mml:mrow></mml:math> radicals; <mml:math alttext="$\left[ {{\text{Fe}}\left( {{\text{H}}_{\text{2}} {\text{O}}} \right)_5 \left( {{\text{OH}}} \right)} \right]^{2 + } $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mrow><mml:mo>[</mml:mo><mml:mrow><mml:mtext>Fe</mml:mtext><mml:msub><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mtext>H</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:mtext>O</mml:mtext></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow><mml:mn>5</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mtext>OH</mml:mtext></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow><mml:mo>]</mml:mo></mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math> being the most photoactive species. The disappearances of the oxidation products were shown to only involve the
attack of <mml:math alttext="${\text{HO}}^ \bullet  $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mtext>HO</mml:mtext></mml:mrow><mml:mo>&#x2022;</mml:mo></mml:msup></mml:mrow></mml:math> radicals; the quantum yields of disappearances are wavelength dependent as the formation
of the hydroxyl radicals is. For prolonged irradiation, the total mineralisation of the oxidation products
was achieved with the formation of sulphate and ammonium ions. The half-lives of products <b>1</b> and <b>2</b> when
submitted to such a process under solar irradiation were estimated to be respectively 12 and 11 min in the
mixture with 100% of monomeric species <mml:math alttext="$\left[ {{\text{Fe}}\left( {{\text{H}}_{\text{2}} {\text{O}}} \right)_5 \left( {{\text{OH}}} \right)} \right]^{2 + } $" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow><mml:mrow><mml:mo>[</mml:mo><mml:mrow><mml:mtext>Fe</mml:mtext><mml:msub><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mtext>H</mml:mtext><mml:mtext>2</mml:mtext></mml:msub><mml:mtext>O</mml:mtext></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow><mml:mn>5</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mtext>OH</mml:mtext></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow><mml:mo>]</mml:mo></mml:mrow></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>. Under these conditions, the total mineralisation is reached within 2 days of exposure.

Pascal  Wong-Wah-Chung

Gilles  Mailhot

Mich&#232;le  Bolte

Iron(III) photoinduced degradation: Catalytic method for <svg style="vertical-align:-0.0pt" height="10.8625" version="1.1" viewBox="0 0 8.9125004 10.8625" width="8.9125004" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,10.8)"><path id="x34" d="M456 178h-96v-72q0 -51 12.5 -62.5t72.5 -16.5v-27h-256v27q65 5 78 17t13 62v72h-260v28q182 271 300 426h40v-407h96v-47zM280 225v295h-2q-107 -148 -196 -295h198z" /></g></svg>,<svg style="vertical-align:-0.0pt" height="17.7125" version="1.1" viewBox="0 0 12.4375 17.7125" width="12.4375" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,17.65)"><use xlink:href="#x34"/></g><g transform="matrix(.012,-0,0,-.012,8.225,9.488)"><path id="x2032" d="M227 744l-123 -338l-31 15l73 368q12 3 41.5 -8t36.5 -20z" /></g></svg>-diaminostilbene-<svg style="vertical-align:-0.0pt" height="10.9125" version="1.1" viewBox="0 0 8.9125004 10.9125" width="8.9125004" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,10.862)"><path id="x32" d="M412 140l28 -9q0 -2 -35 -131h-373v23q112 112 161 170q59 70 92 127t33 115q0 63 -31 98t-86 35q-75 0 -137 -93l-22 20l57 81q55 59 135 59q69 0 118.5 -46.5t49.5 -122.5q0 -62 -29.5 -114t-102.5 -130l-141 -149h186q42 0 58.5 10.5t38.5 56.5z" /></g></svg>,<svg style="vertical-align:-0.0pt" height="17.7125" version="1.1" viewBox="0 0 12.4375 17.7125" width="12.4375" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,17.65)"><use xlink:href="#x32"/></g><g transform="matrix(.012,-0,0,-.012,8.225,9.488)"><use xlink:href="#x2032"/></g></svg>-disulfonic acid removal from water

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<p><em>International Journal of Photoenergy</em> publishes original research and review articles focused on all areas of photoenergy, including photochemistry and solar energy utilization.</p>


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<p>Chief Editor, Giulia Grancini, is based at the University of Pavia, Italy. Her current research work aims at solving the stability and toxicity issues of developing multi-dimensional hybrid interfaces as lego-bricks for a new efficient, stable, and environmentally-friendly solar technology.</p>


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International Journal of Photoenergy - Table of contents 2003

International Journal of Photoenergy | Hindawi

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International Journal of Photoenergy publishes original research and review articles focused on all areas of photoenergy, including photochemistry and solar energy utilization.

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