Photocatalytic Effect of ZnO Crystals on Methylene Blue Solutions

Abstract

Natural water resources are continuing to gain importance due to the increasing human population. Furthermore the waste waters contaminate clean water resources. Consequently importance of the water resources is increasing rapidly. The many industries produce large quantities wastewater containing organic colorants, such as methylene blue (MB). High doses of these type organic colorants are dangerous for all living organisms. Cheap and efficient methods on wastewater treatment are needed.  The organic pollutants can be removed but not destroyed by using traditional wastewater treatment techniques such as coagulation, adsorption on activated carbon, reverse osmosis. Some of these methods are expensive and some of them are insufficient. As an alternative, Advance Oxidation Process (AOP), a cheap and efficient method, have received increased attention for their ability of degrading a wide range of contaminants found in the water resources. Recently, the application of metal oxide semiconductors in the advanced oxidation process (AOP) has gained wide interest for the degrading the organic pollutant found in the environment.

In this study, the photocatalytic activity of ZnO particles on the degradation of MB was carried out under UV light. Three different MB dye content in the 300 mL solution (containing 0.1 g ZnO) were investigated. The results indicate a linear relationship between MB concentration and degradation rate constant.