The influence of the various parameters which govern the kinetics (mas
s of catalyst, wavelength, initial concentration, temperature, radiant
flux, modification of the photocatalyst) has been analyzed. The knowl
edge of these parameters enables one to determine the best conditions
for an optimum quantum yield. The photon appears as a reactant and the
light flux as an additional phase (the 'electromagnetic phase'). Seve
ral examples of polyphasic photocatalytic systems are described with u
p to 5 phases working concertedly, especially in the case of pollutant
removal from used waters.