Advanced Oxidation Processes for the Degradation of Pesticides

Abstract

Photocatalysis process, as an environmental application is a relatively novel subject with tremendous potential in the near future. The basics of heterogeneous photocatalysis, mainly depends on TiO2 and the application of photocatalytic processes to water purification and treatment. Heterogeneous photocatalysis is rapidly expanding Technology for water and air. Hazardous organic wastes from industrial, military, and commercial operations represent one of the greatest challenges to environmental engineers. The use of high energy oxidants such as ozone and H2O2 and/or photons those are able to generate highly reactive intermediates .OH radicals. During the last few years, there has been a plethora of research and development in the area of solar photocatalysis (TiO2 and photo-Fenton). This overview, of the most recent papers on the use of sunlight to produce the ·OH, comments on those most relevant to the development of the technology and summarizes most of the recent research related to the degradation of water contaminants, and pesticide degradation and how solar photocatalysis (coupled with biotreatment) could significantly contribute to the treatment of very persistent toxic compounds. Photodegradation of different herbicides occurred in both aqueous systems; however the presence of TiO2 clearly accelerated the degradation of the three herbicides in comparison with direct photolysis. In the project the technical grade pesticide Malathion degradation was studied which is collected from Dhanuka group of pesticide industries (New Delhi).Titanium Dioxide (TiO2) is used as a photocatalyst. The main aim of the process is to degrade the toxic complex structure of the technical grade Malathion pesticide to harmless product by treating the sample in the UV-reactor by varying pH, catalyst concentration, oxidant (H2O2). Degradation was followed by measuring the chemical oxygen demand (COD).The technical grade pesticide, Malathion degradation was observed nearly 80% by measuring COD reduction and complete adsorption on the TiO2 photocatalyst was observed during the experimental work in the lab.