Survey efficiency of ultraviolet and zinc oxide process (UV/ZnO) for removal of diazinon pesticide from aqueous solution

The presence of persistent organic pollutants and toxics (e.g., pesticides) in ground, surface, and drinking water resources combined with the inability of conventional treatment methods to remove these pollutants have led to the development of advanced oxidation processes. Nowadays, nanophotocatalyst processes are considered as clean and environmentally-friendly treatment methods that can be extensively used for removing contaminants. The objective of the present study was to determine the efficiency of the ultraviolet and zinc oxide (UV/ZnO) process in the removal of diazinon pesticide from aqueous solutions. For the purposes of this study, samples were adjusted in a batch reactor at five different detention times. The pH levels used were 3, 7, and 9. Irradiation was performed using a 125 W medium-pressure mercury lamp. The diazinon concentrations of the samples were 100 and 500 Sg/L and the concentrations of zinc oxide nanoparticles were 50, 100, and 150 mg/L. The highest degradation efficiency was observed at pH 7 (mean = 80.92 ± 30.3), while the lowest was observed for pH 3 (mean 67.11 ± 24.49). Results showed that the optimal concentration of nanoparticles (6-12 nm) was 100 mg L-1

Potoccatalytic oxidation of oganophosphorus pesticides using zinc oxide

Abstract In recent years, the application of heteroge-neous photocatalytic water treatment processses has gained wide attention due to its effectiveness in degra-ding and mineralizing the pesticides. These pesticides are often found in many surface and groundwater sources and their concentration levels often exceed the drinking water permissible limits recommended by Iran and European drinking water standards. The aim of the present study was to investigate the influence of various parameters such as initial malathion and diazinon concentration catalyst amount, initial pH of the reaction medium and pesticide types on the photocatalytic decomposition of pesticides in the presence of ZnO using an ultraviolet lamp as the light source. The best conditions for the photocatalytic degradation of pesticides were obtained. Results showed that the optimal concentration of catalyst was found to be 100 mg. L -1 . The photodegradation efficiency of pesticides increases with the increase of the illumination time. The photodegradation rate of pesticides was higher in alkaline than in acidic conditions. The photocatalytic degradation rate of the malathion was more than diazinon. The photodegradation efficiency decreases with the increase in the initial concentration of pesticides. The photocatalytic system afforded the highest removed percentage at initial concentration for diazinon and malatlion were 100 and 200 mg.L-1 respectivel

Photocatalytic Oxidation of Carbofuran Pesticide Using Zinc Oxide

In recent years, the application of ultraviolet irradiation and zinc oxide (UV/ZnO) process water and wastewater treatment has gained removal activity of the persistence organic compounds. The degradation of carbofuran pesticide was investigated under ultraviolet irradiation and zinc oxide (UV/ZnO) process. Likewise, the effect of the operational parameters such as reaction volume, initial concentration of catalyst, initial carbofuran concentration, light intensity and pH were studied. In this study the (UV/ZnO) process at different initial concentrations (50-250 mg/L), 5 different initial pH and 5 different initial concentration of catalyst was investigated. Analyses were performed by gas chromatography mass spectroscopy. Results showed that the carbofuran initial concentration of 50 mg/L, ZnO concentration of 300 mg/L, pH of 8, light intensity of 125 watts and reaction volume of 150 mL, were the optimum condition for degradation of carbofuran by UV/ZnO system. This study demonstrated that carbofuran could be effectively degraded by ultrasonic irradiation

Removal of malathion insecticide from water by employing acoustical wave technology

Background: Organophosphorus pesticides are one of the most prevalent usages for pest control in the country. Such pesticides enter into water sources by different routes. Since drinking of contaminated water at the higher doses than the standard level, may causes undesirable effects to human health and ecosystem. The object of this research was to investigate the effect of various parameters including time, power and concentration on sonodecomposition of malathion insecticide in the water. Methods: The sonochemical degradation of malathion was investigated using acoustic wave technology (AWT). AWT with 130 kHz was used to study the decomposition of insecticide solution. Samples were analyzed using HPLC at different intervals times. Effectiveness of AWT at different times (20, 40, 60, 80, 100, and 120 minutes), concentrations of malathion at 2, 4 and 8 mg/L as well as powers of device (300W, 400W, 500W) are compared. Results: These findings showed that the degradation of the malathion insecticide at lower concentrations was greater in comparison to higher concentrations. Also, there was positive correlation between power increasing and the ability to malathion degradation Conclusion: The sonodegradation of malathion at different concentrations and powers was successfully achieved. It has been shown that acoustical wave technology can be used to reduce the concentration of dissolved insecticide using high frequency