OZONE DEGRADATION OF SELECTED NONAGRICULTURAL HERBICIDES

This research note investigates the efficiency of ozone for the degrad ation of threeherbicides, propyl-4-methyl-S-oxo-2-imidazolin-2-yl)-nic otinic acid], triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) an d diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] under controlled la boratory conditions. Experiments were conducted at pH 7.5, in a bubble contactor column, with a raw lowland surface water spiked with initia l active ingredient concentrations of 2 mu gL(-1). The ozone doses app lied and consumed were 4.79 and 2.9 mg O(3)L(-1), respectively, and re sulted in removals of 53%, 48% and 90% of imazapyr, triclopyr and diur on, respectively.