Fe3O4 nanoparticles loading on cow dung based activated carbon as an efficient catalyst for catalytic microbubble ozonation of biologically pretreated coal gasification wastewater

• Published in: Journal of environmental management Vol. 267; p. 110615
• Main Authors: Hou, Sen, Jia, Shengyong, Jia, Jinjin, He, Zhengguang, Li, Guirong, Zuo, Qiting, Zhuang, Haifeng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2020
• Subjects: Biologically pretreated coal gasification wastewater; Catalytic ozonation; Cow dung based activated carbon; Fe3O4 nanoparticles; Microbubble ozone; Cow dung based activated carbon; Catalytic ozonation; Biologically pretreated coal gasification wastewater; Fe3O4 nanoparticles; Microbubble ozone
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.110615

Cow dung based activated carbon was successfully modified by Fe3O4 nanoparticles as the novel catalyst (Fe3O4 nanoparticles@CDAC) to improve the microbubble ozonation treating biologically pretreated coal gasification wastewater (BPCGW). When the pH, ozone dosage, ozone bubble diameter and catalyst dosage of the ozonation were 7, 0.4 L/min, 5 μm and 3 g/L, the chemical oxygen demand (COD) removal efficiency reached 74% and the ratio of biochemical oxygen demand in five days/COD (BOD5/COD) increased from 0.04 to 0.52, which were attributed to the electron transfer of Fe2+ and Fe3+ in Fe3O4 and enhanced hydroxyl radicals generation by the reaction of iron ions and ozone. Meanwhile, benzene derivatives, naphthalene and aromatic proteins were significantly removed while multiple chain hydrocarbons and their derivatives composed the main residual organic matters. The catalytic activity was slightly decreased even the catalyst has been reused for five times. Therefore, catalytic microbubble ozonation using Fe3O4 nanoparticles@CDAC represented excellent performance treating BPCGW and it is a promising process for wastewater advanced treatment. [Display omitted] •Biologically pretreated coal gasification wastewater was treated by ozonation.•Cow dung based activated carbon loaded by Fe3O4 nanoparticles promoted the ozonation.•Benzene derivatives, naphthalene and aromatic proteins were significantly removed.•Reaction between ozone and Fe2+/Fe3+ (electron transfer in valences) produced ·OH.•Novel catalyst still showed remarkable catalytic ability after using five times.