EFFECT OF TiO2-COATED SUBSTRATE PHOTOCATALYSIS ON CHLOPYRIFOS INSECTICIDE DEGRADATION

Abstract

The efficiencies of photocatalysis using TiO2-coated substrates to reduce chlorpyrifos insecticides was
evaluated. Three different glass substrates (glass ball, glass slide and glass bead) were prepared and tested with KI
solution for efficiency of oxidation test. It was found that 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 those TiO2-coated substrates
photocatalysis for 15, 30, 45 and 60 minutes. The percentage reduction of chlorpyrifos was calculated. It was shown
that TiO2-coated glass bead photocatalysis had high reduction rate of chlorpyrifos concentration within 15 minutes,
which correlated with an increase in iodine liberation rate. The effectiveness of TiO2 in photocatalysis to reduce
contaminated chlorpyrifos in Chinese kale was determined by treatments with different TiO2-coated substrate
photocatalysis and sampled every 15 minutes for 60 minutes. It was found that TiO2-coated glass bead reduced
chlorpyrifos concentration to 53% when compared with the control. In addition, in the quality of Chinese kale after
treatment withTiO2 in photocatalysis and stored for 12 days at 5 °
C was also investigated. There was no significant
difference in the quality of Chinese kale in weight loss, leaf color, total soluble solids and ascorbic acid content.