JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Xuanyu Ji,Alberto Tiraferri,Xiaofei Zhang,Peng Liu,Zhiwei Gan,John C. Crittenden,Jun Ma,Baicang Liu
Knowledge on the composition and characteristics of dissolved organic matter (DOM) in complex shale gas wastewater (SGW) is critical to evaluate environmental risks and to determine effective management strategies. Herein, five SGW samples from four key shale gas blocks in the Sichuan Basin, China, were comprehensively characterized. Specifically, FT-ICR MS was employed to provide insights into the sources, composition, and characteristics of SGW DOM. Organic matter was characterized by low average molecular weight , high saturation degree, and low aromaticity. Notably, the absence of correlations between molecular-level parameters and spectral indexes might be attributed to the high complexity and variability of SGW. The unique distribution depicted in van Krevelen diagrams suggested various sources of DOM in SGW, such as microbially derived organics in shales and biochemical transformations. Moreover, linear alkyl benzene sulfonates , as well as associated biodegraded metabolites and coproducts, were identified in SGW, implying the distinct anthropogenic imprints and abundant microbial activities . Furthermore, high DOC removal rates (31.42–79.23 %) were achieved by biological treatment, fully supporting the inherently labile nature of SGW and the feasibility of biodegradation for SGW management . Therefore, we conclude that DOM in SGW is a complex but mostly labile mixture reflecting both autochthonous and anthropogenic sources .
研究领域:
环境科学
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化学
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Tianlie Luo,Yueyu Ran,Yaling Li,Xi Ren,Dian Liu,Shuya Guo,Zhongyu Guo,Guo Liu,Yihua Li,Willie J.G.M. Peijnenburg
Dissolved black carbon (DBC) plays a critical but poorly understood role in the photochemical transformation of organic pollutants. Its structural heterogeneity, determined by biomass source and pyrolysis temperature, strongly influences its photosensitization efficiency. This study systematically investigated the molecular characteristics of DBC derived from rice, wheat and corn straw and examined their effects on the photodegradation kinetics and pathways of α-nitroso-β-naphthol (αNβN). Fourier transform ion cyclotron resonance mass spectrometry analysis revealed that DBC primarily comprises CHO compounds with lignin-derived and fused-ring aromatic structures. With increasing pyrolysis temperature, lignin transforms into highly condensed polycyclic aromatic frameworks characterized by enhanced unsaturation and aromaticity. This molecular transformation directly governs the photochemical activity of DBC, as evidenced by linear correlations between the molecular features of DBC (i.e., unsaturation and aromaticity) and its optical properties, steady-state concentrations of reactive intermediates (RIs) and αNβN photolysis rates. Mechanistic studies identified the triplet-excited state of DBC ( 3 DBC ⁎ ) as the dominant RI responsible for αNβN degradation via dehydrogenation, condensation and redox reactions. While most photoproducts exhibit lower ecotoxicity than αNβN, exceptions such as 2-nitro-1-naphthol and coumarin underscore source-dependent risk variations. These findings advance the molecular-level understanding of the environmental implications of DBC, emphasizing its dual function as both a photochemical promoter and a modulator of pollutant behavior.
研究领域:
环境化学
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光化学
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质谱分析
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环境科学
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污染物降解
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Chuanjin Lin,Yanfei Tang,Jing Sun,Bin Dong,Xu Zuxin
In this study, the remediation effects of two types of sludge (ferric-based flocculant and non-ferric-based flocculant) on Cr(VI)-polluted wastewater were evaluated to clarify the key components in sludge hydrothermal solutions responsible for reducing Cr(VI) and understand the underlying molecular-level transformation mechanisms. The results revealed that the primary reactions during the hydrothermal processes were deamination and decarboxylation reactions. Correlation analysis highlighted proteins, reducing sugars, amino groups, and phenolic hydroxyl groups as the major contributors. In-depth analysis of the transformation process of functional groups within dissolved organic matter (DOM) and synergistic redox process between Cr(VI) and DOM in hydrothermal solutions demonstrated that phenolic hydroxyl and amino groups gradually underwent oxidation during reduction of Cr(VI) by DOM, forming aldehyde and carboxyl groups , among the others. Time-dependent density functional theory calculations revealed notable shift of reducing functional groups from ground state to excited state following iron complexation, ultimately facilitating reduction reaction. Subsequent investigations, including soil column leaching and seed germination rate tests, indicated that synergistic redox interaction between Cr(VI) and DOM significantly reduced waterborne heavy metal and toxic organic pollution. These findings carry substantial implications for sludge treatment and remediation of heavy metal pollution in wastewater, offering valuable insights into effective environmental remediation strategies.
研究领域:
环境科学
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化学
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DOI
PubMed
高影响因子
TALANTA
·
2024
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IF 5.6
Bingliang Zhang,Qiyi Wang,Cong Wang,Changmin Wang,Xifeng Shi,Bo Tang
Disinfection byproducts (DBPs) have been extensively investigated during the chlorination of water and wastewater. Although over 700 DBPs have been identified, more than 50% of the total organic halogen remains unknown. Solid phase extraction (SPE) has been emerged as a popular pretreatment approach for enrichment and desalting of unknown DBPs prior to the mass spectrometry analysis. However, the effects of SPE conditions on unknown DBPs in real wastewater have not yet been reported. Herein, three factors (acid types, pH values, and sorbent types) influencing the composition of DBPs in chlorinated municipal wastewater were systematically investigated by Fourier transform ion cyclotron resonance mass spectrometry and statistical analysis. The results indicated that the number of DBPs in different SPE conditions ranged from 280 to 706, and the majority ones were Br-DBPs and CHOX compounds. Compared with H 2 SO 4 , more common DBPs were found when using HCl and HCOOH to adjust the pH values of samples. The unique DBPs extracted at pH 1.0 and 2.0 generally owned higher modified aromaticity index (AI mod ) value and C number than at pH 3.0. The effect of acid types on the extracted DBPs was pH dependent, and the total number of extracted DBPs increased with the increasing of pH value. In terms of sorbent types, the unique DBPs in C18 sorbent possessed low O/C ratios (O/C < 0.6), whereas the unique ones in HLB sorbent owned high O/C ratios (O/C > 0.6). Compared with C18 and HLB sorbents, the unique DBPs extracted in PPL sorbent were characterized by relatively high AI mod and DBE values. Based on mass difference analysis, 1496 precursors-DBPs pairs were identified in all extracted samples, with the highest number of bromine substitution reaction. Overall, the effects of SPE conditions on the composition of unknown DBPs should not be overlooked, and the amount and diversity of DBPs may be underestimated under a single SPE condition. This study provides new methodological references for the accurate identification of unknown DBPs with different characteristics in real wastewater.
研究领域:
环境科学
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分析化学
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DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2024
·Vol. 40
·期 4
·730-736
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IF 3.1
Hu Lin,Tong Shengrui,Xu Yanyong,Zhang Hailiang,Yu Shanshan,Chen Meifang,Ge Maofa
Unsaturated ketones are typical oxygenated volatile organic compounds (OVOCs) with high reactivity, and are important precursors in air pollution. The sources of OVOCs are complex and include direct emissions and secondary oxidation formation of VOCs in the atmosphere. 2-Cyclohexen-1-one is a widespread substance, and is derived from the industrial catalytic oxidation of cyclohexene. In this paper, we investigated the rate constants of the chemical reactions of 2-cyclohexen-1-one with NO 3 radicals, which is (7.25±0.29)×10 −15 cm 3 ·molecule −1 ·s −1 at 298 K and under 1 atm (1 atm=101325Pa). It supplemented the kinetics of NO 3 radicals database, and revealed its effects in the nighttime atmosphere. In addition, the reaction products of 2-cyclohexen-1-one with NO 3 radicals were detected by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), which revealed a series of nitrate esters in the composition of the secondary organic aerosol (SOA), which may reduce atmospheric visibility. Finally, the possible pathways for the generation of the products were developed.
研究领域:
大气化学
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环境科学
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分析化学
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Libing Liu,Lei Du,Sen Lu,Bo Yang,Xu Zhao,Deli Wu,Xunchang Fei,Hongping He,Dongsheng Wang
Various combined processes with pre-coagulation have been developed for biologically treated landfill leachate , but the microscopic-level processes occurring during coagulation remain largely unknown. Herein, dissolved organic matter (DOM) fate using fluorescence excitation emission matrix spectroscopy combined with parallel factor analysis and electrospray ionization coupled Fourier transform-ion cyclotron resonance mass spectrometry and concomitant heavy metal (HM) behaviors were explored at the molecular level. In addition, AlCl 3 and two polyaluminum chloride (PACl) species (dominated by [AlO 4 Al 12 (OH) 24 (H 2 O) 12 ] 7+ and [(AlO 4 ) 2 Al 28 (OH) 56 (H 2 O) 26 ] 18+ , respectively) were used. The results show that all coagulants are efficient at removing DOM. PACl was found to be advantageous over AlCl 3 in overcoming pH fluctuation, which is ascribed to the different dominant mechanisms, namely, entrapment and sweep flocculation for AlCl 3 and charge neutralization for PACl. Consequently, PACl was more effective at removing humic substances , usually high-molecular-weight, oxygen-rich and unsaturated, than protein substances. For HM removal, PACl was likewise better and more stable, where As, Cu, Ni, Co and Hg were removed predominantly via adsorption, and Cr, Zn, Pb, Cd and Mn were removed via coprecipitation . Correlation analysis showed that humic substances tended to complex with HMs and be removed synergistically due to the ubiquitous occurrences of aromatic structures and oxygen-containing functional groups.
研究领域:
环境科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
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