ผลของการล้างด้วย TiO2 ที่ใช้แสงเป็นตัวเร่งร่วมกับโอโซนต่อการลดสารกำจัดศัตรูพืชตกค้างในผักคะน้าหลังการเก็บเกี่ยว

Abstract

This study aims to investigate the optimum condition of TiO2 with photocatalysis and ozone washing to reduce pesticides chlorpyrifos. The three different TiO2 coated media (glass ball, glass slide and glass bead) were prepared and tested with KI solution for efficiency of oxidation test. It was found that of TiO2- coated glass beads at 45 mg/ml for 60 min had the highest iodine liberation rate.A 1 mgL-1 standard chlorpyrifos was subjected to TiO2 with photocatalysis and ozone for 15, 30, 45 and 60 minutes. The percentage reduction of the chlorpyrifos was calculated The results showed that TiO2 with photacatalysis and ozone for 60 minute was the most effective to reduce chlorpyrifos concentration of 36.89%, which correlated with an increase of iodine liberation rate. The effectiveness of TiO2 with photocatalysis and ozone for reduce a contaminated chlorpyrifos in Chinese kale was determined by washing with the treatments of TiO2 with photocatalyst, ozone and the combination and sampling every 15 minutes. It was found that the TiO2 with photocatalysis combined with ozone reduced chlorpyrifos concentration to 53% when compared with the control which was 11%. In addition, the quality changes of Chinese kale after washing with the treatment of TiO2 with phocatalysis and ozone and stored for 12 days at 5 0C also investigated. There was no significant difference of quality of Chinese kale in leaf color, totle soluble solids and ascorbic acid content.