Photo-catalytic Degradation of Industrial Dye Wastewater using ZnFe2O4 Spinel Catalyst Prepared by Co-precipitation method for COD and Color Reduction

Abstract

Dyes have been commonly used in many industrial processes; especially in the textile industry, paper,
printing and plastics industry. These dyes have very complex structures and low biodegradability. In addition, the highly
complexed structured polymers of these dyestuffs cause substantial threat to the environment mainly due to their high
stability and non-degradability and hence the decolorization/degradation of dye effluents has received a large attention.
Semiconductors like TiO2 and ZnO are used in photo-catalytic degradation process but are difficult to separate from
liquid solution after reaction, broad band gap, corrode in water which probably produced secondary pollution and
increased costs. This problem motivates the use of spinel catalysts. In this research, ZnFe2O4 spinel catalyst was
prepared using Co-precipitation having narrow band-gap is used for the degradation of industrial dye wastewater.
Experiments are carried out in sunlight and under UV lamp as a light source. The 500ml sample was taken and dosage
of 0.5 and 1g catalysts used, reaction time 240 min, at sample pH 7.The collected samples after different time interval
analyzed by COD, UV-Visible spectrophotometer for the % degradation. On completion of experiment, catalyst is filtered
and washed with water or ethanol and can be reused again without any treatment.