Photocatalytic Decomposition of Selected Textile Industrial Effluent on Fe-Ti-Zn Oxide Catalysts

Abstract

Textile dyeing industries produce a large volume of wastewater containing printing and dyeing residues of reactive dyes and chemicals. The release of colored organic compounds in the effluents contaminates the surface and ground water and is considered to be the source of nonaesthetic pollution and eutrophication. So, it is imperative to treat the discharge effluents before releasing them to the environment. The present study focused on the characterization of the untreated effluents to understand the pollution status as well as optimize the process parameters for their degradation and mineralization by heterogeneous photocatalysis. The dyeing effluents were collected from three (3) textile dying industries of Rajshahi and Sirajganj districts. The analyzed physicochemical parameters for these effluent samples included pH, EC, DO, TDS, TSS, COD, BOD, TOC, heavy metals, and anions. The analyses were done using several methods such as gravimetric, electrochemical, colorimetric, and optical. The effluents were subjected to photocatalytic degradation using three different photocatalysts as TiO2, ZnO, and Fe2O3. The study optimized various operational parameters, including initial effluent concentration, catalyst concentration, catalyst type, pH, reaction time, and oxidizing agent dose to get the maximum degradation efficiency of an individual and mixed catalyst for a particular textile dyeing effluents.