Microwave-induced persulfate-hydrogen peroxide binary oxidant process for the treatment of dinitrodiazophenol industrial wastewater

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 382; p. 122803
• Main Authors: Chen, Weiming, Luo, Yuanfeng, Ran, Gang, Li, Qibin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.02.2020
• Subjects: Advanced oxidation process; Dinitrodiazophenol industrial wastewater; Hydrogen peroxide; Microwave; Persulfate; Microwave; Hydrogen peroxide; Persulfate; Dinitrodiazophenol industrial wastewater; Advanced oxidation process
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2019.122803

•MW-PS-H2O2 binary-oxidant process was firstly used to treat DDNP wastewater.•The oxidant utilization rate considerably increased with the binary oxidant process.•Both SO4·- and ·OH were major contributions to organics degradation. Microwave (MW) irradiation is a superior approach to a warm-up system than conventional heating, and persulfate (PS) and hydrogen peroxide (H2O2) can be efficiently activated to produce a reactive oxygen species for organic degradation. However, shortcomings remain regarding whether to use a low oxidant or the low treatment efficiency of a single oxidant process. In this study, a PS-H2O2 binary oxidant process induced by MW was developed to treat dinitrodiazophenol industrial wastewater. The best chemical oxygen demand (COD) (73.5%) and color number (CN) (98.1%) removal efficiencies were obtained for the MW-PS-H2O2 process under conditions of a total oxidant dose = 7.4 mM and n(PS)/n(H2O2) = 3.7/3.7. In the MW-PS-H2O2 process, the combination of ·OH and SO4− better degrades organics in DDNP industrial wastewater with the advantages of lower residual salinity (sulfate ions) and less invalid decomposition of excessive H2O2. In addition, benzene ring substances and functional group substances were greatly degraded, and the molecular weight of the organics considerably decreased as a result of the MW-PS-H2O2 process. Overall, the results demonstrate that the MW-PS-H2O2 process is a promising treatment method for dinitrodiazophenol industrial wastewater with high treatment efficacy and high oxidant utilization.