Degradation and Diffusion of Fenobucarb and Triazophos in Water in Furrows of a Fruit Farm to Namdang Canal, Bangbon District, Bangkok

Abstract

 Nowadays, there are pesticides that were focused because of concern of their residues in environments. Moreover, we found residue of some pesticides from carbamate and organophosphate groups in surface waters near agricultural area in Thonburi, Bangkok. Therefore, this research aims to study degradation of carbamate and organophosphate pesticide in water in furrows of a fruit farm continuously in a village of Wararom Petchakasem 81, Bangbon district and to study diffusion of the pesticides from the furrows to a nearest surface water, Klong Namdang. We sprayed fenobucarb and triazophos then randomized water samples were collected from 6 points distributed in the farm then put into a sample at 0, 3, 5, and 7 days after spraying. The canal water sample was collected as
the previous method for 0 days after spraying only. The water samples were assessed the contents of the pesticides by Liquid chromatography - mass spectrophotometer (LC-MS) and Gas chromatography - flame photometric detector (GC-FPD), respectively. The research was done during October, 2024 – June, 2025. Statistic F was used for analyzing variation and linear regression and statistic t was used for mean comparison, respectively. We found that means of content of the pesticide residues, in water in the farm collecting from different days after spraying the pesticides were not significantly different (p=0.7731). Moreover, the pesticides were degraded within 4.89 and 6.83 days after spraying with the degradation rate of 0.4110 and 0.2927 µg/l/day, respectively. It meant that the pesticides degraded in a closed rate. However, means of the residue contents in water in furrows of the farm and the canal were significantly different (p=0.0004). It meant that the pesticides may distributed from the farm to the canal. The results showed the risk of the pesticides to environment and health of the community because the residues were not in the standard of water quality of surface water identifying by Pollution Control Department and World Health Organization.