Photodegradation of Carbofuran in Paddy Water Samples

Abstract Rice fields are one of the agricultural sectors in Malaysia that are heavily pesticide-treated. This study aimed to determine how carbofuran degrades in paddy water and what happens to its metabolite products, carbofuran phenol, and 3-ketocarbofuran. The experiment was conducted in two distinct ways, with one water sample being exposed to sunshine and the other remaining in the dark. Within 56 days of observation, the study discovered that carbofuran decomposed very slowly in all conditions. The water sample exposed to sunlight showed a faster degradation rate, 0.04 day-1, compared to the water kept in the dark at 0.0186 day-1. The results also demonstrated that photolysis and hydrolysis enhance the degradation of the carbofuran in the water. Both 3-ketocarbofuran and carbofuran–phenol was detected as metabolites with low concentration levels, ranging from 0.03 to 0.23 ppm. These metabolites are considered 'emerging pollutants' as they can be detected in the environment and may post-treat as much as the parent compounds themselves. Hence, this study is trying to fill in the research gap to assess the route and rate of carbofuran and its transformation products.