Study on Fenton Oxidation Promoted by Ultrasound Irradiation for Pulping and Papermaking Wastewater

In order to improve the degradation efficiency of pulping and papermaking wastewater, the combination oxidation process of Fenton with ultrasonic irradiation was carried out. The processes of ultrasonic irradiation alone and Fenton oxidation alone on pulping and papermaking wastewater treatment were optimized respectively. Basing on the optimum process of Fenton oxidation, the synergistic effect of ultrasonic treatment was also confirmed. Through the optimum process treatment, chroma removal rate of wastewater reached above 90%, turbidity removal rate over 80%, and COD reduced to 60 mg/L. The FTIR (ATR) spectra of wastewaters, treated by three oxidation systems above, were tested respectively. The results showed that Fenton treatment and ultrasound irradiation both caused the damage of ester linkage of carboxylic group of lignin and the degradation of aromatic structure. Comparably, US-Fenton (ultrasound and Fenton treatment) process had better oxidation ability than that of Fenton oxidation alone.