Reverse Osmosis Coupling Multi-Catalytic Ozonation (RO-MCO) in Treating Printing and Dyeing Wastewater and Membrane Concentrate: Removal Performance and Mechanism

In the face of high demand for reuse from printing and dyeing industries in centralized wastewater treatment of Jiangsu Province, reverse osmosis (RO) process is routinely used in wastewater recycling. However, the membrane concentrate is high in salinity, with high chromaticity and complex composition. Ozone oxidation, as an efficient and clean advanced oxidation process, is widely used but also suffers from several problems such as poor mass transfer and catalytic efficiency. In this paper, a novel aluminum-carbon based metal-doped composite ozone catalyst was designed, and RO coupling Multi-Catalytic Oxidation was constructed in treating biotreatment tail water. The optimal parameters of catalyst dosage of 0.5 g L-1, ozone concentration of 5 mg L-1 and 30% H2O2 dosage of 10 mg L-1 were obtained. After long-term operation experiments, the combined process has been proven to achieve safe discharge and recycling of the tail water, with low ecological risk to the external water environment.