Efficient optimization of photocatalytic process for azo dyes

Abstract

The need of fresh water in our time has become a problem of important concern. Restore water for new uses makes purification an essential process to achieve a desired degree of quality. This need depends on each different purpose, such as purification of drinking water or recycle water for industrial need. Due to the toxic characteristics of non-biodegradable organic pollutants, new treatment technologies must be studied and Advanced Oxidation Processes (AOP’s) come up as suitable for degradation of a wide range of organic contaminants in polluted water. The optimization of photocatalysis is an important issue to turn this process viable. Organic pollutants in effluents threats the environment in several ways, in this context, textile dyes are the major responsible for the colored wastewaters disposed at effluents. This work presents the experimental results of utilizing HNO3 and NaNO3 mixture in aqueous solution for the optimization of the photocatalytic activity. 97% of the dye was degraded in 16 min. Thus, the mechanism of reaction is discussed about a new source of hydroxyl radicals which reacts with the pollutant, as it happens in troposphere.