Efficient Degradation of Paper Mill Effluent by Synergy of Microdischarge Plasma and Fenton-Like Process

Global paper production is increasing every year to meet the surging demand for writing/printing, packing, and tissues. Large quantities of liquid and solid wastes are being generated during paper manufacturing processes. In this study, the efficiency of combining nonthermal microdischarge plasma and a Fenton-like process to degrade real paper mill effluent is investigated. Air microdischarge plasma was characterized using optical emission spectroscopy (OES), and the reactive species were identified. The UV-Vis absorption studies revealed 42.1% and 45.5% effluent content degradation with Plasma/H2O2 and Plasma/Fenton-like processes, respectively. A highly acidic medium enhanced the degradation by favoring the oxidation of Fenton's reagent in the Plasma/Fe3+ process and the degradation mechanism is discussed. The combined effect of the Plasma/Fenton-like process at pH of 3, exhibited a synergistic effect on the effluent degradation with 86.3% removal rate, and mineralization of 46.7% was achieved. In addition, the OH radical scavenging study on the degradation percentage was evaluated. Functional groups formed during the reaction were analyzed using attenuated total reflection-Fourier transform infrared (ATR-FTIR) studies. The changes in the physicochemical parameters of the effluent were measured. The study delineated that the microdischarge plasma combined with Fenton-like process can be employed for the degradation of paper and pulp mill effluent and allied liquid wastes effectively.