Micro-nano bubble ozonation for effective treatment of ibuprofen-laden wastewater and enhanced anaerobic digestion performance

Sining Zhou; Lei Qiao; Yanyan Jia; Samir Kumar Khanal; Lianpeng Sun; Hui Lu

doi:10.1016/j.watres.2024.123006

Micro-nano bubble ozonation for effective treatment of ibuprofen-laden wastewater and enhanced anaerobic digestion performance

Water Res. 2024 Dec 19:273:123006. doi: 10.1016/j.watres.2024.123006. Online ahead of print.

Authors

Sining Zhou¹, Lei Qiao¹, Yanyan Jia², Samir Kumar Khanal³, Lianpeng Sun¹, Hui Lu⁴

Affiliations

¹ School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, PR China.
² School of Ecology, Sun Yat-sen University, Shenzhen, PR China.
³ Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Ma̅noa, Honolulu, HI, United States; Department of Environmental Engineering, Korea University Sejong Campus, Sejong-ro 2511 Sejong 2511, Korea.
⁴ School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou, PR China. Electronic address: lvhui3@mail.sysu.edu.cn.

PMID: 39721508
DOI: 10.1016/j.watres.2024.123006

Abstract

The pharmaceutical industry plays a crucial role in driving global economic growth but also poses substantial environmental challenges, particularly in the efficient treatment of production wastewater. This study investigates the efficacy of micro-nano bubble (MNB) ozonation for treating high-strength ibuprofen (IBU)-laden wastewater (49.9 ± 2.3 mg/L) and mitigating its inhibitory effects on the anaerobic digestion (AD) of intralipid (IL)-laden wastewater. Our findings demonstrated that MNB ozonation achieved a 99.0 % removal efficiency of IBU within 70 min, significantly surpassing the 69.8 % efficiency observed with conventional ozonation under optimal conditions. Both conventional and MNB ozonation primarily transformed IBU through oxidation processes, including hydroxylation and the conversion of CH bonds to C = O groups, along with carbon cleavage. However, MNB ozonation markedly reduced the toxicity of IBU-laden wastewater by further transforming toxic by-products, particularly under mildly alkaline conditions (pH 7.2 and 9.0). This reduction in toxicity led to a significant improvement in subsequent AD performance; specifically, a 70-min MNB ozonation pretreatment enhanced methane production by 48.1 %, increased chemical oxygen demand removal by 35.6 %, and reduced fatty acid accumulation compared to the control without pretreatment. Additionally, the effluent from MNB ozonation positively impacted the microbial community, particularly by enriching syntrophic bacteria and methanogens. Overall, these findings offered new insights into the behavior and toxicity of IBU oxidation by-products in both conventional and MNB ozonation processes. Furthermore, this study proposed a novel strategy for the combined treatment of IBU- and IL-laden wastewaters, establishing a robust foundation for advancing MNB ozonation technology in engineered pharmaceutical wastewater treatment.

Keywords: Anaerobic digestion performance; Bacterial community structure; DFT calculation; Pharmaceutical wastewater; Transformation products.