Conventional wastewater treatment processes are increasingly difficult to fulfill strict standards of
achieving the required quality. Therefore, it is necessary to apply processes that in an efficient and
economically justified way reach the necessary limits in order to discharge wastewater into the
recipient. The process of photolysis represents the degradation of the starting pollutant practically to
water and carbon dioxide. The whole process takes place under the action of a UV lamp that imitated
solar irradiation. The process is environmentally justified since, unlike some other advanced
oxidation processes – AOPs, there is no use of additional, hazardous, chemicals which possibly results
in the precipitates formation that are leading to further treatment. In this paper, photolytic degradation
of pesticide thiophanate methyl was performed in doubled wall quartz reactor equipped with a
thermoregulation system. Reaction was forced under Osram ULTRA VITALUX UV lamp (300W).
Kinetics of photodecomposition process was followed by pseudo-first order. In certain time periods,
specimens were sampled, filtered and monitored by UV spectrophotometer Shimadzu 1800 with an
aim to determine the concentration of xenobiotic. Complete degradation of present xenobiotics was
obtained after 240 min. With an aim to enhance the degradation process, hydrogen peroxide was
added as a boosting agent which cause a shortening in demanded time (150 min) for complete
degradation. Verification of the success of decomposition was confirmed by the obtained values of
chemical oxygen demand (COD), which reveal that the established system has a basis for real
application in industrial or municipal wastewater
