Article
Environmental Sciences
Na Wu, Bingqing Lu, Jianmin Chen, Xiang Li
Summary: This study investigates the ability of particles inhaled into the respiratory tract to generate hydroxyl radicals, finding that accumulation-mode particles are significant in promoting hydroxyl radical generation. The study also shows that this ability is mainly related to transition metals and quinones, with sources including biomass burning, incomplete combustion, mobile & industry, and mineral dust.
ENVIRONMENTAL POLLUTION
(2021)
Article
Engineering, Environmental
Jinlai Wei, Ting Fang, Pascale S. J. Lakey, Manabu Shiraiwa
Summary: This study reveals that the deposition of fine particles and iron in the respiratory system can generate organic radicals in surrogate lungfluid (SLF). Iron ions significantly enhance the yield of organic radicals by facilitating the decomposition of organic peroxides. Ascorbate mediates the redox cycling of iron ions to sustain the decomposition of organic peroxides. In addition, antioxidants are efficient at scavenging hydroxyl radicals and superoxide.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Environmental Sciences
Haoran Yu, Joseph Varghese Puthussery, Yixiang Wang, Vishal Verma
Summary: The study assessed the oxidative potential (OP) of water-soluble and methanol-soluble fractions of ambient fine particulate matter (PM2.5) in the Midwestern United States. Results showed significant spatial and seasonal differences in OP activities, with methanol-soluble OP generally exhibiting higher activity levels. Methanol-soluble OP also showed stronger site-to-site correlations compared to water-soluble OP, indicating a better extraction of redox-active compounds from various emission sources into methanol.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Acoustics
Nanda V. Ranade, Vivek V. Ranade
Summary: Cavitation processes, involving the collapse of cavities, generate intense physico-chemical effects that are useful for various applications. However, existing single cavity models are computationally demanding and not easily integrated with cavitation device or reactor scale models, limiting their usefulness. This study introduces artificial neural network (ANN) based surrogate models that accurately represent the complex effects of cavity collapse. The performance of the trained ANN was evaluated using unseen data, showing good simulation results within and beyond the training range. The presented methodology and results are beneficial for developing high-fidelity CFD models of cavitation devices/reactors.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Chemistry, Physical
Pijun Duan, Xinning Liu, Binhua Liu, Muhammad Akram, Yanwei Li, Jingwen Pan, Qinyan Yue, Baoyu Gao, Xing Xu
Summary: The presence of phosphate was found to increase the effectiveness of PMS activation for pollutants removal in AOPs, promoting the generation of SO4 center dot- through efficient breaking of the O-O bond of PMS. The yields of SO4 center dot- were linearly dependent on phosphate concentration, while the yields of .OH remained constant.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Environmental Sciences
Kubra Ulucan-Altuntas, Senem Yazici Guvenc, Emine Can-Guven, Fatih Ilhan, Gamze Varank
Summary: This study investigated the degradation of oxytetracycline by heat-activated peroxydisulfate and peroxymonosulfate processes. Response surface methodology was used to evaluate the effect of process parameters on oxytetracycline removal efficiency, showing significant results for both processes. The predicted oxytetracycline removal efficiencies for the PDS and PMS processes were 89.7% and 84.0%, respectively, with the PDS process having higher kinetic constants at all pH values than the PMS process.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Engineering, Environmental
Jiangzhou Xie, Changyong Zhang, T. David Waite
Summary: Anodic oxidation is a promising treatment technology for removing organic pollutants from wastewaters. Hydroxyl radicals are the primary species used for oxidizing organics. This review discusses the methods of identifying hydroxyl radicals, debates on the validity of experimental results, and quantification methods. It also highlights the generation mechanisms of hydroxyl radicals and their utilization in electrochemical reactors. The key challenges for anodic oxidation technology are identified as eliminating errors in identification, establishing effective quantification methods, developing cost-effective anode materials, and optimizing reactor designs for maximum utilization efficiency of hydroxyl radicals.
Article
Engineering, Environmental
Alexander John, Irene Carra, Bruce Jefferson, Monika Jodkowska, Adam Brookes, Peter Jarvis
Summary: The application of microbubbles in water treatment has shown to enhance gas-liquid contacting processes and compound removal compared to conventional bubbling techniques. However, this study found that there was no significant difference in hydroxyl radical generation between microbubble and conventional bubble ozonation systems.
CHEMICAL ENGINEERING JOURNAL
(2022)
Review
Environmental Sciences
Jiayao Chen, Heiko J. Jahn, Haitong Zhe Sun, Zhi Ning, Weisheng Lu, Kin Fai Ho, Tony J. Ward
Summary: Exposure measurement error is a significant bias source in epidemiological studies. This study assessed the validity of using ambient measurements as proxies for personal exposures and found that the correlation between personal exposure and ambient concentrations is influenced by health status and pollutant type.
ENVIRONMENTAL POLLUTION
(2022)
Article
Environmental Sciences
Liina Onga, Eneliis Kattel-Salusoo, Marina Trapido, Sergei Preis
Summary: This study experimentally investigated the oxidation of the widely used anti-inflammatory corticosteroid dexamethasone (DXM) using gas-phase pulsed corona discharge (PCD). The results showed that PCD had higher energy efficiency compared to ozonation and was effective in oxidizing DXM at different pH levels and concentrations. Radical oxidation was identified as the dominant transformation pathway for DXM. However, high concentrations of DXM during PCD treatment may lead to increased toxicity, which requires further investigation.
Article
Engineering, Environmental
Lei Wang, Yi Chen, Baiyang Chen, Jie Yang
Summary: This study showed that reduced oxygen mainly generates center dot OH, and photolysis products can trigger the formation of H2O2 under 254 nm UV. Additionally, evidence of direct photolysis-induced indirect photolysis phenomenon was presented, along with a comprehensive methodology to identify the presence and sources of radicals.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Chemistry, Physical
Ji Young Hwang, Gun-hee Moon, Bupmo Kim, Takashi Tachikawa, Tetsuro Majima, Seungwoo Hong, Kangwoo Cho, Wooyul Kim, Wonyong Choi
Summary: The generation of mobile free OH radicals on anatase through a reductive conversion of dissolved O2 is crucial in achieving the mineralization of non-adsorbing substrates, while surface trapped holes lead to the generation of surface-bound OH radicals on both anatase and rutile. Understanding the production pathway of OH radicals in photocatalysis will help optimize their generation for efficient photocatalytic oxidation of pollutants.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Multidisciplinary
Jiaxin Lv, Ruixin Chen, Zhen Wu, Yang Bai, Han Song, Chen Tian, Mengye Wang, Zhang Lin
Summary: The enrichment of microplastics in polar ice is a common phenomenon. Therefore, studying the degradation behavior of microplastics in frozen environments is important in evaluating their impact on polar ecosystems. This study investigated the degradation of polystyrene (PS) in frozen anoxic Fe(ii)-containing solutions, revealing a 14.6-fold higher degradation rate compared to water. The study provides insights into an overlooked pathway for microplastic degradation in frozen environments, which is crucial for understanding their environmental behavior.
ENVIRONMENTAL SCIENCE-NANO
(2023)
Article
Chemistry, Multidisciplinary
Runfeng Lin, Junkai Liu, Weilin Xu, Zicheng Liu, Xiang He, Canze Zheng, Miaomiao Kang, Xue Li, Zhijun Zhang, Hai-Tao Feng, Jacky W. Y. Lam, Dong Wang, Ming Chen, Ben Zhong Tang
Summary: In this work, a pyrazine-based near-infrared type I photosensitizer (PS) with remarkable donor-acceptor effect and efficient intramolecular motions was developed. The PS exhibited high photothermal conversion efficiency and strong hydroxyl radical generation due to its vigorous intramolecular motions. It also demonstrated excellent imaging-guided cancer synergistic therapy, stimulating the development of advanced PS and solid-state intramolecular motions for biomedical applications.
ADVANCED MATERIALS
(2023)
Article
Environmental Sciences
Caofan Xiao, Xueqi Chen, Xiumei Tao, Xian Liu, Xun Wang, Lei Zhu
Summary: In this study, B-doped TiO2 photocatalytic materials were synthesized by sol-gel method and characterized by XRD, TEM, XPS, and other methods. The results showed that 4%B-TiO2 nanopowder had smaller grain size, higher porosity, and lower bandgap energy compared to undoped TiO2. Scavenging experiments and ESR results revealed that ·OH was the main active species. Therefore, under 365 nm UV light, the degradation efficiency of AP reached 98.8% in 30 minutes when using 10 mg/L initial concentration of AP and 1 g/L loading of 4%B-TiO2, due to the efficient generation of ·OH by B-TiO2.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)