TREATMENT OF WASTEWATER CONTAINING DYE MIXTURE USING PYRITE CINDER IN HETEROGENEOUS FENTON PROCESS

Dyes and pigments are important industrial chemicals. The structures of dyes can be very diverse and complex, so the treatment of wastewater containing these chemicals can be very challenging. Fenton process is particularly attractive and effective to degrade a wide range of dyes. In order to reduce the expenses related to applying these processes, the use of waste materials in the heterogeneous Fenton process, as alternative sources of catalytic iron, is recently investigated in scientific literature. In this study effluent was obtained from dye house unit of carpet factory (Serbia) and it contained the mixture of six commercial dyes. Pyrite cinder, a residue from sulfuric acid production, was also used in this process as a source of catalytic iron. Effluent decolourization rate reached 75% under optimal condition. Additionally, the research included further characterization of obtained effluent in terms of mineralization and metal leaching. A significant degree of mineralization was achieved under the applied conditions. Although, dye degradation was satisfactory, the metal content of the solutions after the process suggests that an additional treatment step, by using lime, is necessary. Results indicated that the applied waste material is effective as iron source in modified Fenton processes for treatment of effluent containing mixture of dyes.