Degradação de 2,4-Dinitrofenol com processo de oxidação avançada do tipo O3/OH-

Abstract

2,4-Dinitrophenol or 2,4-DNF is a yellow, nitroderivated organic compound of the formula C6H4N2O5. Due to its use in several manufacturing processes such as explosives, pharmaceuticals, pesticides, pigments, dyes, wood preservatives and rubber chemicals, it is commonly found in effluents from these industries. However, due to some characteristics such as toxicity and recalcitrance, it can hinder treatment by conventional systems. An alternative would be the use of Advanced Oxidative Processes (OAP), which is defined as a set of methods in which there is the generation of free radicals, especially the hydroxyl radical (OH), agent of high oxidizing power, which under certain conditions physical and chemical properties can promote the mineralization of toxic components that conventional treatments cannot eliminate. In this context, the objective of this study was to study the degradation of 2,4-DNF using an OAP type O3/ OH-. The experimental conditions included the use of two types of reactors on a laboratory scale to evaluate the pH effect. The analytical response for assessing the% degradation of 2,4-DNF was the reduction in absorbance measured at its maximum absorption wavelength (ʎmax = 360nm). The experimental system consisted of an ozonator, a silica column, an air flow meter and a compressor. The results obtained showed that the alkaline pH offers a better degradation condition, however, conditioned to the presence of a minimum concentration of ozone, which was better provided by a fast mixing reactor in which the ozone transfer efficiency was significantly higher, having been possible, a total discoloration of the solution and degradation of 98.4% of 2,4-DNF, suggesting high potential of the process.