Table 2: The effect of moisture, iron(III), and humic substances at the surface of Kaolinite on the photodegradation rate constant of mesotrione and metsulfuron methyl; layer thickness = 100 µm; (organic compound) = 5.2 µmol g−1. Irradiation was performed with a Sunlight simulator.

CompoundDry layer
×10−2
min−1
Moisture
×10−2
min−1
Iron(III); 1.0 wt%
×10−2
min−1
Humic acids; 2.0 wt%
×10−2
min−1

Mesotrione0.400.920.730.12
Metsulfuron methyl2.218.04.91.3