Analysis of anti-foulant degradation in water environment by UV-Vis spectroscopy

Abstract

Zinc pyrithione (ZnPT) is widely used as booster biocide in antifouling paints after banning on use of organotin compounds. Photolysis of ZnPT in aquerious solution was investigated using a photospectroscopic technique Photolysis experiment using xenon lamp was found to simulate the decomposition by natural sunlight. The photospectroscopic study successfully identified one of the degradation products and measured the kinetics of ZnPT's photolysis. It is concluded that ZnPT was decomposed by the irradiation to form Pyridine-2-sulfonic acid (PSA). Kinetics constant of ZnPT photolysis was proportional to the irradiation power and independent of temperature. The half live of ZnPT in solution was estimated to be about 17 minutes in Tokyo, Japan.