The photodegradation of pesticides was investigated on adsorbed phases: silica, kaolin, bentonite and on a standard soil. Kinetic results show that the photodegradation of phenmedipham is dependant on the nature of the support. On silica and bentonite the degradation is immediate while the photodegradation is slow on kaolin and standard soil. Also, the nature of the photodegradation depends on the reactional mechanism on the support.
