Article
Engineering, Environmental
Yunhui Zhang, Yun Wang, Yong Li, Zuxin Xu, Huaizheng Li, Wei Jin
Summary: Dissolved effluent organic matter (EfOM) is crucial for the ozonation decomposition and hydroxyl radical (& BULL;OH) scavenging in the degradation of trace organic contaminants (TrOCs) in municipal secondary effluents. This study isolated EfOM into six fractions to understand their reaction kinetics and roles in & BULL;OH chain reactions. The results showed that hydrophilic fractions (HiF) had higher reaction rate constants (kEfOM-& BULL;OH) than hydrophobic fractions (HoF), with hydrophilic base (HiB) being the most important fraction in ozone decomposition and & BULL;OH reaction.
Article
Engineering, Environmental
Chenglong Yu, Yuxi Lu, Yanting Zhang, Ao Qian, Peng Zhang, Man Tong, Songhu Yuan
Summary: This study investigated the production of hydroxyl radicals (.OH) from solid humic acid during oxidation. The results demonstrated that solid humic acid transferred electrons to oxygen, leading to the generation of .OH. The modeling results also confirmed that reduced solid organic matter played a significant role in .OH production.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Haiyan Du, Yuanxin Cao, Zhe Li, Lina Li, Huacheng Xu
Summary: The study found that seasonal sediment samples from Lake Poyang in China exhibited high concentrations of HO' with spatial heterogeneity, showing positive correlations with Fe(II), sedimentary organic carbon, and dissolved organic carbon content, indicating a general contribution of these reduced substances to HO' formation. Moreover, the contents and species of Fe(II) and DOM were highlighted as important factors in manipulating HO' yield.
Article
Environmental Sciences
Xi-Xi Wang, Bao-Ming Liu, Min-Feng Lu, Yu-Ping Li, Ying-Ying Jiang, Ming-Xing Zhao, Zhen-Xing Huang, Yang Pan, Heng-Feng Miao, Wen-Quan Ruan
Summary: This study analyzed the physicochemical properties, components, and disinfection byproduct formation potentials (DBPFPs) of algal organic matter (AOM) and natural organic matter (NOM) in a typical eutrophic lake. Results showed that AOM had higher organic nitrogen content and exhibited higher DBPFPs, especially for nitrogenous DBPFP. The study also found that the molecular weight distribution between AOM and NOM was similar, but AOM had higher concentrations of building blocks while NOM had higher concentrations of biopolymers and humics (HS).
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Federico Bacilieri, Anssi V. Vahatalo, Luca Carena, Mingjie Wang, Pin Gao, Marco Minella, Davide Vione
Summary: The formation quantum yields of photochemically produced reactive intermediates (PPRIs) by irradiated CDOM decrease with increasing irradiation wavelength. Specifically, the formation quantum yields of the excited triplet states of CDOM and singlet oxygen show an exponentially decreasing trend with wavelength. However, the trend for center dot OH is different, with more effective production occurring under UVB irradiation than predicted by an exponential function. CDOM is found to be able to trigger center dot OH photogeneration in deep waters to a higher extent than UVB-absorbing nitrate or UVB + UVA-absorbing nitrite.
Article
Engineering, Environmental
Yixuan Wang, Danyu Huang, Chenghao Ge, Xiaolei Wang, Changyin Zhu, Ning Chen, Guodong Fang, Dongmei Zhou
Summary: Recently, the production of hydroxyl radical (•OH) during soil redox fluctuations has been reported, but the low efficiency of contaminant degradation hinders engineering remediation. This study found that the addition of low-molecular-weight organic acids (LMWOAs), such as oxalic acid (OA) and citric acid (CA), significantly enhanced •OH production during oxygenation of anoxic paddy slurries. The highest •OH accumulation was observed with 0.5 mM CA due to its strong capacity for complexation.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Xingyue Li, Shiqi Liu, Shiqi Wang, Li Feng, Peng Gao, Yongze Liu, Liqiu Zhang
Summary: This study investigated the various advanced treatment processes for the secondary effluent of municipal wastewater treatment plants and their impact on dissolved organic matter (DOM) and disinfection byproduct (DBP) generation. The results showed that the biological aerated filter (BAF) and ozonation processes significantly affected DOM characteristics and subsequent DBP generation. Low molecular weight hydrophobic DOM removal resulted in a reduction in DBP production, while ozonation led to an increase in halogenated aldehydes (HALs) and halogenated ketones (HKs). Humic acid (HA) was identified as the main organic type in DOM and an important precursor for DBPs. The specific ultraviolet absorbance at 254 nm (SUVA) was found to be a critical factor for trichloromethane (TCM) generation. Large molecule hydrophobic DOM contributed the most to the formation of carbonaceous disinfection by-products, and NH4+-N content affected the generation of nitrogenous disinfection by-products.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Environmental
Shuwen Yan, Jiaqian Sun, Haitao Sha, Qi Li, Jianxin Nie, Jianmin Zou, Chiheng Chu, Weihua Song
Summary: Hydroxyl radicals (OH·) are reactive species generated through solar irradiation of chromophoric dissolved organic matter (CDOM) in surface waters. This study found that the concentration of OH· in CDOM microphase is significantly higher than in the aqueous phase, suggesting CDOM behaves as a natural microreactor. The elevated concentrations of photogenerated OH· within CDOM may improve understanding of hydrophobic pollutant degradation and play important roles in the phototransformation of CDOM.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Mengxi Tan, Shaochong Liu, Ning Chen, Yuliang Li, Liqiang Ge, Changyin Zhu, Dongmei Zhou
Summary: The role of iron phases in preserving organic carbon can be reversed under redox-fluctuation conditions, especially for Fe(II) minerals-protected organic carbon. Hydroxyl radicals produced during oxidation processes can induce mineralization of organic carbon associated with Fe(II) minerals.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Yutong Liang, Robert J. Weber, Pawel K. Misztal, Coty N. Jen, Allen H. Goldstein
Summary: The number and severity of large wildfires in the western United States have been increasing for decades. This research focuses on the measurement of volatile organic compounds (VOCs) emitted from biomass burning (BB) during the Northern California wildfires in October 2017. The results indicate that VOCs play a significant role in the composition of smoke plumes and their chemistry during transport, impacting ozone formation and levels in the San Francisco Bay Area.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Jinxiu Lou, Huijie Lu, Wei Wang, Lizhong Zhu
Summary: This study evaluated the correlation between molecular weight and HBQs generation of river NOM. It was found that HBQs were approximately 9 times more abundant in NOM fractions larger than 50 kDa compared to low molecular weight fractions. The presence of lignin-like and highly oxygen compounds in NOM was found to play critical roles in the formation of HBQs. Derivatizing certain compounds in NOM reduced HBQs yields significantly.
Article
Engineering, Environmental
Dingxiang Wang, Jiahao He, Jun Ma, Jing Zhang, Timothy J. Strathmann
Summary: Permanganate and ferrate oxidations are widely used advanced treatment processes to degrade organic components in secondary effluents from municipal wastewater treatment plants. However, these reactions are sensitive to the dissolved effluent organic matter (EfOM) and do not mineralize it but change its molecular composition.
Article
Engineering, Environmental
Woorim Lee, Sandro Marcotullio, Hoonsik Yeom, Heejong Son, Tae-Hun Kim, Yunho Lee
Summary: This study investigated the reaction kinetics and degradation efficiency of methylparaben and its halogenated products (Cl-, Br-, Cl,Cl-, Br,Cl-, and Br,Br-methylparabens) during ozonation and UV 254 /H2O2 treatment. The results showed that ozonation and UV/H2O2 were effective in controlling the presence of methylparaben and its halogenated products.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Engineering, Environmental
Ang Hu, Kyoung-Soon Jang, Fanfan Meng, James Stegen, Andrew J. Tanentzap, Mira Choi, Jay T. Lennon, Janne Soininen, Jianjun Wang
Summary: This study examines the deterministic and stochastic processes governing the assembly of dissolved organic matter (DOM) molecules in aquatic microcosms. The researchers found that labile or recalcitrant molecules in active fractions are primarily governed by deterministic processes, while stochastic processes are more important for the assembly of molecules within inactive fractions. Interestingly, the importance of deterministic selection increases with global change gradients for recalcitrant molecules in both active and inactive fractions. These findings highlight the importance of understanding the assembly and turnover of organic carbon in a changing world.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Shelby Buckley, Frank Leresche, Blair Hanson, Fernando L. Rosario-Ortiz
Summary: The complex effects of ozonation on the photo-physical and size-based properties of dissolved organic matter (DOM) were investigated using two DOM isolates, Suwannee River Fulvic Acid (SRFA) and Pony Lake Fulvic Acid (PLFA). The results showed that ozonation affected the fluorescence quantum yield differently in low and high apparent molecular weight (AMW) fractions. It also increased the singlet oxygen quantum yield in the low AMW fractions, indicating these fractions are the most photoreactive. The study further suggested that the photoactive and fluorescent fractions of DOM are likely independent pools of chromophores from different AMW fractions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
