Abstract: The ozone-ultraviolet (O3-UV) process, which has emerged for advanced treatment of the secondary effluents (SEs) of wastewater treatment plants (WWTPs), requires optimization that balances the contributions of O3 (chemical oxidation) and hydroxyl radicals (HO•, advanced oxidation) to minimize energy consumption. In this study, a novel bench-scale mini-fluidic O3-UV system (MFOUS) was developed, allowing for accurate determination and convenient adjustment of the key operational parameters including O3 mass loading (ML) and UV fluence (Fp). The degradation of refractory organic compounds in the O3-UV process, expressed by chemical oxygen demand (COD) reduction and biodegradability (i.e., ratio of biological oxygen demand (BOD) to COD) enhancement, was investigated for three typical SEs with different reactivities toward O3. Moreover, an evaluation method for the energy consumption of the O3-UV process was established, enabling fine optimization of operational parameters to balance the contributions of O3 and HO•. For example, to achieve 40% of COD reduction in SE-1, the ML and Fp should be optimized to 0.340 kg m−3 and 0.009 einstein m−2, respectively, resulting in the lowest energy consumption of 7.29 kWh m−3. Through optimizing the O3-UV process for energy conservation, this study will help the WWTPs to achieve carbon-neutral goal in the future.

Biography: Dr. Zhimin Qiang is a distinguished professor at the School of Environmental Science & Engineering, Shanghai Jiao Tong University. He was a recipient of the National Science Fund for Distinguished Young Scholars, and had served as the director of Drinking Water Science and Technology of Chinese Academy of Sciences, and the director of Sate Key Laboratory of Environmental Aquatic Chemistry of China. His research covers advanced treatment, green disinfection, and safe distribution of water and wastewater. Prof. Qiang has led over 40 research projects, published about 250 SCI papers (H index = 62) and 120 Chinese papers, and been recognized as a Highly Cited Researcher by Elsevier in China. He holds 20 innovation patents and has received 8 national/provincial honors and awards.