Improved wet oxidation for the treatment of dyeing wastewater concentrate from membrane separation process

In this paper, a series of wet oxidation experiments was carried out in a 2-l autoclave reactor. To achieve a significant reduction of the reaction temperature and pressure, two new oxidation methods were applied. One was to partially or totally replace oxygen with a stronger oxidant, viz. hydrogen peroxide, and the other was to introduce a catalyst. Both processes were found to achieve a higher initial reaction rate of TOC and colour reduction at lower reaction temperatures and pressures as compared with the conventional wet air oxidation. By combining the two new improved methods to treat the dyeing wastewater concentrate from a membrane separation process, almost 80% of TOC reduction and 90% of colour removal were achieved within half-an-hour at a reaction temperature of 110°C and a system total pressure of 50 kPa.