Degradation of Reactive Red 180 and Safranin and a Comparative Analysis of Photocatalysis and Photo-Membrane Systems for Real Textile Wastewater Treatment

Abstract

This study examined the degradation of Reactive Red 180 and safranin using zinc oxide photocatalysis. Complete dye removal was achieved for both dyes under optimal conditions within 2 h. For Reactive Red 180, the optimum conditions were pH 10, 0.5 g/L zinc oxide, 25 ppm dye concentration, and 1 L volume. For safranin, the conditions were pH 10, 0.75 g/L ZnO, 25 ppm dye concentration, and 1 L volume. In terms of reusability, the removal efficiency of Reactive Red 180 decreased from 100% at the 1st cycle to 82% after five cycles, while safranin removal remained constant across all cycles. A comparison between photocatalysis and photo-membrane systems was conducted on real textile wastewater with an original pH of 10.45 and a Pt/Co value of 1000 ppm. In the Photocatalytic Membrane Reactor, 100% dye removal and 48% chemical oxygen demand removal were achieved in 2 h using a zinc oxide amount of 0.75 g/L. In the photocatalytic system, 86% dye removal efficiency and 20% chemical oxygen demand removal efficiency were achieved after 4 h. The photocatalytic membrane reactor presents an efficient, durable, and cost-effective solution for various industrial and environmental processes, making it a promising alternative to traditional photocatalytic systems.