Coupling Between Laser Irradiation and TiO2 Nanoparticles on Efficient Decontamination of Some Pesticide's Residues from Orange and Tomato Puree


In this paper, we focused on the development of photocatalytic degradation to be a promising method for the treatment of decontaminated fruits and vegetables with pesticides. We investigate the coupling between Laser irradiation with TiO2 nanoparticles catalyst in order to study the photocatalytic degradation of metalaxyl, chlorpyrifos, and diazinon from artificially contaminated tomato puree and orange puree. Degradation products were identified by gas chromatography-mass spectrometry (GC–MS). The influences of different parameters such as catalyst concentration, irradiation time on the reaction rate were ascertained and optimum conditions for maximum degradation were determined. The degradation percentage of all pesticides was achieved under optimized conditions (1g/L catalyst at the irradiation time of 120 min). The study proved that the coupling between TiO2 nanoparticles and laser irradiation has a high potential for photocatalytic degradation of diazinon, chlorpyrifos, and metalaxyl from orange puree and tomato puree. And also, proved that the efficient degradation of pesticide residues increased with an increase in laser irradiation time (for 60 min) and catalyst (TiO2nanoparticles) dosage in all experiments. Maximum reduction >80% was observed in diazinon in all puree treatments.

The processing factor (PFs) was generally less than one which indicates that all processes can reduce pesticide residues in all puree treatments. The less efficient removal of pesticides residues from all treatments without Laser irradiation (dark TiO2100mg)

We concluded that the optimum conditions for the photodegradation of diazinon, chlorpyrifos, and metalaxyl in all puree treatments were TiO2100mg catalyst concentration and after 60 min of laser irradiation.