Kinetics of photochemical degradation of imazapyr in aqueous solutions

Kinetic parameters of imazapyr photodegradation in aqueous solutions are presented at two pH values and different concentrations. To study the effect of UV and sunlight irradiation, reactions were carried out by using a pyrex reactor equipped with UV high pressure mercury arc and a solar simulator (Heraeus Suntest CPS+). The depletion of imazapyr concentration always followed first order kinetic. The half-lives were 19.0 and 24.7 minutes at pH 7.0 and 4.0, respectively. The influence of organic matter on the photolytic process was studied irradiating a solution of imazapyr with suspended humic acids (1:1 w:w).