Gas-Liquid-Solid Reactions of Polyvinyl Alcohol on Oxidation Treatments for Environmental Pollution Remediation

Polyvinyl alcohol (PVA) oxidation in liquid-phase was studied in a batch high-pressure reactor at 140 to 240;C and 0.7 MPa oxygen partial pressure. The two-phase (gas-liquid) non-catalytic wet oxidation was compared with a three-phase system (gas-liquid-solid) using CuO-ZnO/Al2O3 and Mn-Ce-O oxides catalysts. This study pointed out oxidation processes as quite promising technologies for industrial effluents containing PVA, leading to high reductions in PVA and total organic carbon (TOC) levels. Catalysts showed high activity at 180;C and carbon adsorption was not observed; Mn-Ce-O showed significant leaching to the liquid-phase, compared with CuO-ZnO/Al2O3. Acetic and formic acids were detected as refractory compounds for oxidation.