Wet oxidation of PVA-containing desizing wastewater

Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by vario us wet oxidation methods. Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODCr) and total organic carbon (TOC) removal rate. Up to 90 % of the initial CODCr was removed by wet air oxidation(WAO) at 270 degrees C with stoichiometric oxygen supply, while at temperature of 200 degrees C , the CODCr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperat ure of 150 degrees C. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. initial solution p H was observed to play a significant role in PWAO and WPO where H2O2 was em ployed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODCr removal increases in the order: WAO, CWAO, PWA O and WPO.