Effect of different parameters on photocatalytic degradation to remove pesticide intermediates and synthetic dyes in water Ayomal Fernando , U.S.K Weliwegamage, G.W.C.S Perera College of Chemical Sciences, Institute of Chemistry Ceylon, Sri Lanka Water pollution due to pesticides and organic pollutants is a serious environmental problem that can harm the ecosystem and human health. photocatalytic degradation is a promising technology for the removal of pesticides and organic pollutants as it is effective, environmentally friendly, and cost-effective. The present study explored the effects of various parameters such as radiation type, pH of the solution, type of photocatalyst and the particle size, initial concentration of dyes and pesticides, Amount of H 2 O 2 concentration, reaction temperature, and photocatalyst load on photocatalysis of each compound. TiO 2 nanoparticles, TiO 2 microparticles, and MnO 2 microparticles were used to compare the efficiency of the photocatalysts. Methylene Blue, Methyl Orange, and Acid Red 1 were used as synthetic dyes and p-nitrophenol, and p-Nitroaniline as pesticide intermediates were taken as organic pollutants. The highest degradation efficiency was observed under UV irradiation compared to sunlight for all compounds. At pH 8 Methylene Blue, at pH 2 Methyl Orange, Acid Red 1, and p-nitrophenol, and pH 11 p-nitroaniline showed the highest degradation. The study showed that nano TiO 2 photocatalysts had higher degrading efficiency than MnO 2 and TiO 2 microparticles. Furthermore, it was discovered that the chemical’s photodegradation efficiency was greatest at low concentrations. In addition, the Photodegradation efficiency of compounds was higher at higher H 2 O 2 concentrations (0.3 M). The results indicated that the optimal conditions for the highest degradation efficiency varied depending on the compound. Methylene blue, methyl orange, and acid red 1 showed high degradation efficiency at high temperatures like 55°C, while p-nitrophenol and p-nitroaniline showed higher degradation efficiency at 45 °C. The study further showed that all chemicals displayed the highest degradation efficiency when loaded with 20 mg of TiO2 nanoparticle photocatalyst. Overall, the study suggests that photocatalytic degradation using TiO 2 nanoparticles is a promising technology for the removal of organic pollutants from water. References 1. Mohomad Nageeb Rashed. Organic Pollutants Monitoring, Risk and Treatment ; 2013. https://doi.org/10.5772/55953. 2. Muhammad Farhan Hanafi, N. S. A Review on the Current Techniques and Technologies of Organic Pollutants Removal from Water/Waste Water ; 2020. https://doi.org/https:doi.org/10.1016/j.matpr.2021.01.265. 3. Advance Oxidation Process for Waste Water Treatment ; Suresh C. Ameta Rakshith Ameta, Ed.; ScienceDirect, 2018. https:// doi.org/https//doi.org/10.1016/C2016-0-00384-4. 4. Fan shi and Bryan Morreale. Novel Materials for Carbon Dioxide Mitigation Technology ; 2015. https://doi.org/https//doi. org/10.1016/C2012-0-01304-X. 5. Carmen, Z.; Daniel, S. Textile Organic Dyes – Characteristics, Polluting Effects and Separation/Elimination Procedures from Industrial Effluents – A Critical Overview. Org. Pollut. Ten Years After Stock. Conv. - Environ. Anal. Update. 2012 . https://doi. org/10.5772/32373.
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