246 results on '"Dongqiang Zhu"'
Search Results
2. Molecular signature of soil organic matter under different land uses in the Lake Chaohu Basin
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Han Gao, Huixin Li, Chen Lin, Pedro J.J. Alvarez, Caroline A. Masiello, Dongqiang Zhu, Ao Kong, and Xiaolei Qu
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High-throughput untargeted mass spectrometry screening ,Mass spectrum processing algorithm ,Soil organic matter ,Molecular signature ,Land use ,Ecology ,QH540-549.5 ,Environmental sciences ,GE1-350 - Abstract
The concentration and molecular composition of soil organic matter (SOM) are important factors in mitigation against climate change as well as providing other ecosystem services. Our quantitative understanding of how land use influences SOM molecular composition and associated turnover dynamics is limited, which underscores the need for high-throughput analytical approaches and molecular marker signatures to clarify this etiology. Combining a high-throughput untargeted mass spectrometry screening and molecular markers, we show that forest, farmland and urban land uses result in distinct molecular signatures of SOM in the Lake Chaohu Basin. Molecular markers indicate that forest SOM has abundant carbon contents from vegetation and condensed organic carbon, leading to high soil organic carbon (SOC) concentration. Farmland SOM has moderate carbon contents from vegetation, and limited content of condensed organic carbon, with SOC significantly lower than that of forest soils. Urban SOM has high abundance of condensed organic carbon markers due to anthropogenic activities but relatively low in markers from vegetation. Consistently, urban soils have the highest black carbon/SOC ratio among these land uses. Overall, our results suggested that the molecular signature of SOM varies significantly with land use in the Lake Chaohu Basin, influencing carbon dynamics. Our strategy of molecular fingerprinting and marker discovery is expected to enlighten further research on SOM molecular signatures and cycling dynamics.
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- 2022
- Full Text
- View/download PDF
3. Future research needs for environmental science in China
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Dongqiang Zhu, Weiqiang Chen, Xiaolei Qu, Yuming Zheng, Jun Bi, Haidong Kan, Yongming Luo, Guangguo Ying, Eddy Y. Zeng, Fangjie Zhao, Lingyan Zhu, Yongguan Zhu, and Shu Tao
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Environmental science ,China ,Challenges ,Opportunities ,Research needs ,Geography (General) ,G1-922 ,Environmental sciences ,GE1-350 - Abstract
Environmental science is an interdisciplinary science developed in the process of understanding and solving ecological and environmental problems. In order to tackle these problems, environmental science research is expected to reveal the source, behavior, fate, exposure, and risks of pollutants in the environment and develop potential solutions to control pollution. It provides the scientific basis for decision-makers to establish environmental and economic policies, and promote concerted efforts for the sustainable development of society. Here, we articulate the development patterns, challenges, and future research needs of environmental science in China based on literature review and expert panel discussion. Environmental science research has evolved significantly in the past decade with an increasing diversity of environmental pollutants and health impacts, new technologies and methods, deepening fusion of multiple disciplines, and emerging solutions for pollution control. Its future development relies on the advances in our knowledge on the fate and transport of pollutants, regional environmental processes, ecotoxicological effects, environmental exposure and health effects, environmental analysis and monitoring, source control and reduction, environmental remediation, as well as environmental risk management. For each of these fields, we summarize the significant challenges and highlight the research demands for China. Based on the status quo of China's environmental science research and future needs, we provide recommendations to promote its future development, including encouraging innovation and interdisciplinary research, providing decision support for national needs, encouraging international collaboration, and improving collaboration mechanisms.
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- 2021
- Full Text
- View/download PDF
4. A nanozyme-like colorimetric sensing strategy based on persulfate activation on Co-based metal–organic frameworks
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Zehui Deng, Qingling Xiao, Heyun Fu, Shourong Zheng, Pedro J.J. Alvarez, Dongqiang Zhu, Zhaoyi Xu, and Xiaolei Qu
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Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
This study developed a nanozyme-like colorimetric sensing strategy based on persulfate activation for the first time, outperforming the H2O2 activation approach.
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- 2023
5. Bacterial community assembly and antibiotic resistance genes in soils exposed to antibiotics at environmentally relevant concentrations
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Zeyou Chen, Wei Zhang, Anping Peng, Yike Shen, Xin Jin, Robert D. Stedtfeld, Stephen A. Boyd, Brian J. Teppen, James M. Tiedje, Cheng Gu, Dongqiang Zhu, Yi Luo, and Hui Li
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Microbiology ,Ecology, Evolution, Behavior and Systematics - Published
- 2023
6. Contributions of biomass burning to global and regional SO2 emissions
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Zhihan Luo, Wenxiao Zhang, Haoran Xu, Guofeng Shen, Hefa Cheng, Dongqiang Zhu, Yu'ang Ren, Xiao Yun, Bengang Li, Yilin Chen, Wenjun Meng, Xinyuan Yu, Shu Tao, Huizhong Shen, Qirui Zhong, and Earth and Climate
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Atmospheric Science ,South asia ,010504 meteorology & atmospheric sciences ,business.industry ,Fossil fuel ,Biomass ,010501 environmental sciences ,01 natural sciences ,Hazardous air pollutants ,Residential sector ,Spatial difference ,Sulfur dioxide (SO) ,Absolute amount ,Environmental protection ,SDG 13 - Climate Action ,Environmental science ,Coal ,Temporal trend ,business ,Biomass burning ,0105 earth and related environmental sciences - Abstract
Harmful SO2 largely originates from coal and oil combustions, but in some areas the biomass burning contribution could not be ignored. Here, we evaluated SO2 emissions from biomass burning (BB-SO2) with largely focusing on regional difference and temporal trends in the relative contributions of biomass burning from different sectors. Globally, the biomass burning emitted 4.26 (3.20–6.20) Tg SO2 in 2014, contributing 4.0% of the total SO2 emissions stemming from anthropogenic sources and natural open fires. But in some African and South Asian countries, biomass burning was a major source of SO2 with the contribution as high as 80–90%. Regarding sector contributions of biomass SO2, open fires contributed nearly half, followed by the residential sector (~29%) on the global scale, however, substantially different profiles were revealed across countries. Residential sector is the largest anthropogenic BB-SO2 source in the developing countries, while in the developed countries, industry and energy production were the two main anthropogenic BB-SO2sources. From 1960 to 2014, biomass SO2 emission, either the absolute amount or the relative contribution to the total, increased in the U.S. and Europe, and the contributions were over 20% in some countries. The biomass burning SO2 emission showed an increasing trend in India and a unimodal change in China, while a decreasing trend in the relative contributions were revealed in these two largest developing countries, which were 2.7% and 0.8%, respectively in 2014. With unignorable biomass burning contribution to SO2, as well as other hazardous air pollutants, in some regions, it is suggested that in assessing climate and health impacts of promoted biomass utilization when phasing out of fossil fuels, multiple components should be co-evaluated.
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- 2021
7. Future research needs for environmental science in China
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Eddy Y. Zeng, Shu Tao, Weiqiang Chen, Fang-Jie Zhao, Xiaolei Qu, Yongming Luo, Yuming Zheng, Lingyan Zhu, Guangguo Ying, Haidong Kan, Dongqiang Zhu, Yong-Guan Zhu, and Jun Bi
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Sustainable development ,China ,Geography (General) ,Decision support system ,Ecology ,Environmental analysis ,Status quo ,Process (engineering) ,Emerging technologies ,media_common.quotation_subject ,Geography, Planning and Development ,Environmental exposure ,Environmental science ,Environmental sciences ,Opportunities ,G1-922 ,Research needs ,GE1-350 ,Challenges ,Environmental planning ,Nature and Landscape Conservation ,Earth-Surface Processes ,media_common ,Panel discussion - Abstract
Environmental science is an interdisciplinary science developed in the process of understanding and solving ecological and environmental problems. In order to tackle these problems, environmental science research is expected to reveal the source, behavior, fate, exposure, and risks of pollutants in the environment and develop potential solutions to control pollution. It provides the scientific basis for decision-makers to establish environmental and economic policies, and promote concerted efforts for the sustainable development of society. Here, we articulate the development patterns, challenges, and future research needs of environmental science in China based on literature review and expert panel discussion. Environmental science research has evolved significantly in the past decade with an increasing diversity of environmental pollutants and health impacts, new technologies and methods, deepening fusion of multiple disciplines, and emerging solutions for pollution control. Its future development relies on the advances in our knowledge on the fate and transport of pollutants, regional environmental processes, ecotoxicological effects, environmental exposure and health effects, environmental analysis and monitoring, source control and reduction, environmental remediation, as well as environmental risk management. For each of these fields, we summarize the significant challenges and highlight the research demands for China. Based on the status quo of China's environmental science research and future needs, we provide recommendations to promote its future development, including encouraging innovation and interdisciplinary research, providing decision support for national needs, encouraging international collaboration, and improving collaboration mechanisms.
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- 2021
8. Mechanism for selective binding of aromatic compounds on oxygen-rich graphene nanosheets based on molecule size/polarity matching
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Heyun Fu, Bingyu Wang, Dongqiang Zhu, Zhicheng Zhou, Shidong Bao, Xiaolei Qu, Yong Guo, Lan Ling, Shourong Zheng, Pu Duan, Jingdong Mao, Klaus Schmidt-Rohr, Shu Tao, and Pedro J. J. Alvarez
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Multidisciplinary - Abstract
Selective binding of organic compounds is the cornerstone of many important industrial and pharmaceutical applications. Here, we achieved highly selective binding of aromatic compounds in aqueous solution and gas phase by oxygen-enriched graphene oxide (GO) nanosheets via a previously unknown mechanism based on size matching and polarity matching. Oxygen-containing functional groups (predominately epoxies and hydroxyls) on the nongraphitized aliphatic carbons of the basal plane of GO formed highly polar regions that encompass graphitic regions slightly larger than the benzene ring. This facilitated size match–based interactions between small apolar compounds and the isolated aromatic region of GO, resulting in high binding selectivity relative to larger apolar compounds. The interactions between the functional group(s) of polar aromatics and the epoxy/hydroxyl groups around the isolated aromatic region of GO enhanced binding selectivity relative to similar-sized apolar aromatics. These findings provide opportunities for precision separations and molecular recognition enabled by size/polarity match–based selectivity.
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- 2022
9. Spatially Resolved Emission Factors to Reduce Uncertainties in Air Pollutant Emission Estimates from the Residential Sector
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Yingjun Chen, Guofeng Shen, Lai-Guo Chen, Ningning Zhang, Junji Cao, Yuxuan Ren, Yaojie Li, Gang Li, Xinlei Liu, Yong Zhang, Haitao Lu, Wei Du, Shu Tao, Zhihan Luo, Dongqiang Zhu, Xiao-Ming Liang, Hefa Cheng, Ming Liu, Bengang Li, Yuanchen Chen, and Zhe Qian
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Pollutant ,Air Pollutants ,China ,Briquette ,business.industry ,Anthracite ,General Chemistry ,010501 environmental sciences ,Combustion ,Solid fuel ,Atmospheric sciences ,01 natural sciences ,Coal ,Stove ,Environmental Chemistry ,Environmental science ,Particulate Matter ,Biomass ,Emission inventory ,Household Articles ,business ,0105 earth and related environmental sciences - Abstract
The residential sector is a major source of air pollutant emission inventory uncertainties. A nationwide field emission measurement campaign was conducted in rural China to evaluate the variabilities of realistic emission factors (EFs) from indoor solid fuel combustion. For a total of 1313 burning events, the overall average EFs (±standard deviation) of PM2.5 were 8.93 ± 6.95 and 7.33 ± 9.01 g/kg for biomass and coals, respectively, and 89.3 ± 51.2 and 114 ± 87 g/kg for CO. Higher EFs were found from burning of uncompressed straws, while lower EFs were found from processed biomass pellets, coal briquettes, and relatively clean anthracite coals. Modified combustion efficiency was found to be the most significant factor associated with variations in CO EFs, whereas for PM2.5, fuel and stove differences determined its variations. Weak correlations between PM2.5 and CO indicated high uncertainties in using CO as a surrogate for PM2.5. EFs accurately fit log-normal distributions, and obvious spatial heterogeneity was observed attributed to different fuel-stove combinations across the country. Emission estimation variabilities, which are determined by the interquartile ranges divided by the median values, were notably reduced when spatially resolved EFs were adopted in the inventory.
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- 2021
10. Differentiated-Rate Clean Heating Strategy with Superior Environmental and Health Benefits in Northern China
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Jianmin Ma, Dongqiang Zhu, Hefa Cheng, Wenxiao Zhang, Xiao Yun, Junfeng Liu, Wenjun Meng, Xilong Wang, Guofeng Shen, Huizhong Shen, Qirui Zhong, Yu'ang Ren, Haoran Xu, Xinyuan Yu, Yilin Chen, and Shu Tao
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Air pollution ,General Chemistry ,010501 environmental sciences ,Health benefits ,Per capita income ,medicine.disease_cause ,01 natural sciences ,Age and gender ,Premature death ,Urbanization ,medicine ,Environmental Chemistry ,Environmental science ,Penetration rate ,Socioeconomics ,China ,0105 earth and related environmental sciences - Abstract
Residential heating using solid fuels contributes significantly to air pollution and has subsequent health impacts in China. To mitigate emissions, a clean heating campaign (CHC-1) covering 28 municipalities has been implemented. Although only a single penetration rate was initially planned by CHC-1 for all municipalities, outcomes in the different municipalities varied considerably. Recently, a second phase (CHC-2) has been launched for the remaining 128 municipalities in northern China with once again a fixed penetration rate set. Here, we quantified factors that affected the penetration rates of CHC-1, developed an intervention scheme with differentiated targets for CHC-2, and compared the environmental and health benefits of the fixed- and differentiated-rate strategies. We found that the penetration rates of CHC-1 depended on per capita income, terrain slope, and population density and that such relationships could be quantified using a piecewise regression model. This model was applied to develop a differentiated-rate strategy for CHC-2. It clearly evidenced that a differentiated scheme would be more environmentally beneficial. Although the same number of rural households can achieve clean heating under both intervention scenarios, the proposed differentiated strategy can prevent 30 000 (23 000-34 000) premature deaths associated with residential heating annually compared to the 26 000 (21 000-31 000) premature deaths prevented under the fixed-rate scheme. Differences among gender and age groups and the effects of urbanization and aging are also discussed.
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- 2020
11. The anti-tumor effect of miR-539-3p on colon cancer via regulating cell viability, motility, and nude mouse tumorigenicity with CDK14 inhibition
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Tao Hu, Jian Liu, Jiangui Yu, Zhuo Wang, Dongqiang Zhu, and Chengwu Jin
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0301 basic medicine ,TUNEL assay ,medicine.diagnostic_test ,biology ,Cell growth ,business.industry ,Colorectal cancer ,Gastroenterology ,medicine.disease ,biology.organism_classification ,Flow cytometry ,Metastasis ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Nude mouse ,Oncology ,Apoptosis ,030220 oncology & carcinogenesis ,Cancer research ,Medicine ,Original Article ,Viability assay ,business - Abstract
Background Colon cancer is one of the major causes of morbidity and mortality worldwide. MicroRNAs (miRNAs) play important functions in the growth and metastasis of colon cancer. This study aimed to investigate the anti-tumor effect of micro ribonucleic acid 539-3p (miR-539-3p) on colon cancer via regulation of cell viability, motility, and nude mouse tumorigenicity with cyclin-dependent kinase 14 (CDK14) inhibition. Methods The target relationship between miR-539-3p and CDK14 was predicted using TargetScan software, and were detected by luciferase reporter assay. Cell counting kit-8 (CCK-8) assay and flow cytometry were employed to examine cell proliferation and apoptosis. Western blotting was employed to measure the protein expression levels of p27, cleaved caspase-3, and epithelial (E)- and neural (N)-cadherin. The effect of miR-539-3p on tumor growth was evaluated by establishing a xenograft tumor model in nude mice. Results The target relationship of CDK14 and miR-539-3p was identified as a negative regulator. Overexpression of miR-539-3p significantly inhibited SW620 and SW480 cell proliferation, promoted cell apoptosis, and suppressed cell invasion by targeting CDK14. The xenograft tumor model showed that the overexpression of miR-539-3p reduced tumor weight and volume. Immunohistochemical staining revealed that the overexpression of miR-539-3p inhibited the expression of Ki67 and E-cadherin. Additionally, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining showed that overexpression of miR-539-3p induced apoptosis. Conclusions Overexpression of miR-539-3p inhibited SW620 and SW480 cell proliferation, promoted cell apoptosis, and suppressed cell invasion by targeting CDK14. Therefore, miR-539-3p may be a useful diagnostic and therapeutic biomarker for colon cancer.
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- 2020
12. Dissolved Black Carbon Facilitates Photoreduction of Hg(II) to Hg(0) and Reduces Mercury Uptake by Lettuce (Lactuca sativa L.)
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Dongqiang Zhu, Langlang Li, Jiubin Chen, Xiaolei Qu, Heyun Fu, Xingjun Wang, and Shu Tao
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biology ,Chemistry ,dBc ,Fraction (chemistry) ,Lactuca ,General Chemistry ,Carbon black ,010501 environmental sciences ,biology.organism_classification ,01 natural sciences ,Mercury uptake ,Environmental chemistry ,Biochar ,Environmental Chemistry ,0105 earth and related environmental sciences - Abstract
Here, we investigated the photoreduction of Hg(II) (Hg(NO3)2) mediated by dissolved black carbon (DBC
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- 2020
13. Directional Oxidation of Amine-Containing Phenolic Pharmaceuticals by Aqueous Dissolved Oxygen under Dark Conditions Catalyzed by Nitrogen-Doped Multiwall Carbon Nanotubes
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Langsha Yi, Wanchao Yu, Dongqiang Zhu, Heyun Fu, Chenhui Wei, Xiaolei Qu, and Pedro J. J. Alvarez
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chemistry.chemical_classification ,Reactive oxygen species ,Aqueous solution ,Health impact ,Inorganic chemistry ,Nitrogen doped ,Carbon nanotube ,Catalysis ,law.invention ,chemistry ,Chemistry (miscellaneous) ,law ,Environmental Chemistry ,Chemical Engineering (miscellaneous) ,Amine gas treating ,Electron paramagnetic resonance ,Water Science and Technology - Abstract
As a widely used class of pharmaceuticals, amine-containing phenolic compounds are commonly found in water systems, which has raised growing concern about their potential health impact and requires...
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- 2020
14. Assessment of Bioavailability of Biochar-Sorbed Tetracycline to Escherichia coli for Activation of Antibiotic Resistance Genes
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Hui Li, Bingyu Wang, Dongqiang Zhu, and Yingjie Zhang
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biology ,Chemistry ,medicine.drug_class ,Tetracycline ,Antibiotics ,Sorption ,General Chemistry ,biology.organism_classification ,medicine.disease_cause ,Bioavailability ,Biochar ,medicine ,Environmental Chemistry ,Bioreporter ,Food science ,Escherichia coli ,Bacteria ,medicine.drug - Abstract
Human overuse and misuse of antibiotics have caused the wide dissemination of antibiotics in the environment, which has promoted the development and proliferation of antibiotic resistance genes (ARGs) in soils. Biochar (BC) with strong sorption affinity to many antibiotics is considered to sequester antibiotics and hence mitigate their impacts to bacterial communities in soils. However, little is known about whether BC-sorbed antibiotics are bioavailable and exert selective pressure on soil bacteria. In this study, we probed the bioavailability of tetracycline sorbed by BCs prepared from rice-, wheat-, maize-, and bean-straw feedstock using Escherichia coli MC4100/pTGM bioreporter strain. The results revealed that BC-sorbed tetracycline was still bioavailable to the E. coli attached to BC surfaces. Tetracycline sorbed by BCs prepared at 400 °C (BC400) demonstrated a higher bioavailability to bacteria compared to that sorbed by BCs prepared at 500 °C (BC500). Tetracycline could be sorbed primarily in the small pores of BC500 where bacteria could not access due to the size exclusion to bacteria. In contrast, tetracycline could be sorbed mainly on BC400 surfaces where bacteria could conveniently access tetracycline. Increasing the ambient humidity apparently enhanced the bioavailability of BC400-sorbed tetracycline. BC500-sorbed tetracycline exposed to varying levels of ambient humidity showed no significant changes in bioavailability, indicating that water could not effectively mobilize tetracycline from BC500 pores to surfaces where bacteria could access tetracycline. The results from this study suggest that BCs prepared at a higher pyrolysis temperature could be more effective to sequester tetracycline and mitigate the selective pressure on soil bacteria.
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- 2020
15. An investigation on hygroscopic properties of 15 black carbon (BC)-containing particles from different carbon sources: roles of organic and inorganic components
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Dongqiang Zhu, Xiaolei Qu, Shu Tao, Minli Wang, Yiqun Chen, Heyun Fu, and Bengang Li
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Atmospheric Science ,Aqueous solution ,010504 meteorology & atmospheric sciences ,Vapour pressure of water ,Analytical chemistry ,Humidity ,chemistry.chemical_element ,Carbon black ,010501 environmental sciences ,01 natural sciences ,lcsh:QC1-999 ,lcsh:Chemistry ,lcsh:QD1-999 ,chemistry ,Gravimetric analysis ,Relative humidity ,Carbon ,lcsh:Physics ,Water vapor ,0105 earth and related environmental sciences - Abstract
The hygroscopic behavior of black carbon (BC)-containing particles (BCPs) has a significant impact on global and regional climate change. However, the mechanism and factors controlling the hygroscopicity of BCPs from different carbon sources are not well understood. Here, we systematically measured the equilibrium and kinetics of water uptake by 15 different BCPs (10 herb-derived BCPs, 2 wood-derived BCPs, and 3 soot-type BCPs) using a gravimetric water vapor sorption method combined with in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). In the gravimetric analysis, the sorption–desorption equilibrium isotherms were measured under continuous-stepwise water vapor pressure conditions, while the kinetics was measured at a variety of humidity levels obtained by different saturated aqueous salt solutions. The equilibrium water uptake of the tested group of BCPs at high relative humidity (>80 %) positively correlated to the dissolved mineral content (0.01–13.0 wt %) (R2=0.86, P=0.0001), the content of the thermogravimetrically analyzed organic carbon (OCTGA, 4.48–15.25 wt %) (R2=0.52, P=0.002), and the content of the alkali-extracted organic carbon (OCAE, 0.14–8.39 wt %) (R2=0.80, P=0.0001). In contrast, no positive correlation was obtained with the content of total organic carbon or elemental carbon. Among the major soluble ionic constituents, chloride and ammonium were each correlated with the equilibrium water uptake at high relative humidity. Compared with the herbal BCPs and soot, the woody BCPs had much lower equilibrium water uptake, especially at high relative humidity, likely due to the very low dissolved mineral content and OC content. The DRIFTS analysis provided generally consistent results at low relative humidity. The kinetics of water uptake (measured by pseudo-second-order rate constant) correlated to the content of OCTGA and OCAE as well as the content of chloride and ammonium at low relative humidity (33 %) but to the porosity of BCPs at high relative humidity (94 %). This was the first study to show that BCPs of different types and sources had greatly varying hygroscopic properties.
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- 2020
16. Role of Extracellular Polymeric Substances in Microbial Reduction of Arsenate to Arsenite by Escherichia coli and Bacillus subtilis
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Xiaolei Qu, Fuxing Kang, Dongqiang Zhu, Heyun Fu, Shu Tao, Pedro J. J. Alvarez, and Xinwei Zhou
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biology ,Arsenate ,food and beverages ,chemistry.chemical_element ,General Chemistry ,Bacillus subtilis ,010501 environmental sciences ,Arsenite Transporting ATPases ,biology.organism_classification ,medicine.disease_cause ,01 natural sciences ,chemistry.chemical_compound ,Extracellular polymeric substance ,chemistry ,Biochemistry ,medicine ,Environmental Chemistry ,Escherichia coli ,Bacteria ,Arsenic ,0105 earth and related environmental sciences ,Arsenite - Abstract
We show that arsenate can be readily reduced to arsenite on cell surfaces of common bacteria (E. coli or B. subtilis) or in aqueous dissolved extracellular polymeric substances (EPS) extracted from...
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- 2020
17. Comparing Photoactivities of Dissolved Organic Matter Released from Rice Straw-Pyrolyzed Biochar and Composted Rice Straw
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Yafang Liu, Minli Wang, Shujun Yin, Lekai Xie, Xiaolei Qu, Heyun Fu, Quan Shi, Feng Zhou, Fuliu Xu, Shu Tao, and Dongqiang Zhu
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Soot ,Charcoal ,Composting ,Environmental Chemistry ,Oryza ,General Chemistry ,Dissolved Organic Matter ,Tannins ,Carbon - Abstract
Here, we systematically compared the photoactivity and photobleaching behavior between dissolved black carbon (DBC) from rice straw biochar and leached dissolved organic carbon (LDOC) from rice straw compost using complementary techniques. The Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis showed that DBC was dominated by polycyclic aromatic (55.1%) and tannin-like molecules (24.1%), while LDOC was dominated by lignin-like (58.9%) and tannin-like molecules (19.7%). Under simulated sunlight conditions, DBC had much higher apparent quantum yields for
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- 2022
18. Specific ion effects on the aggregation behavior of aquatic natural organic matter
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Yuxuan Yao, Fanchao Xu, Heyun Fu, Dongqiang Zhu, Xiaolei Qu, Pedro J. J. Alvarez, Daqiang Yin, and Qilin Li
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chemistry.chemical_classification ,Chemistry ,Inorganic chemistry ,Enthalpy ,Intermolecular force ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Divalent ,Biomaterials ,Surface tension ,Electrokinetic phenomena ,Colloid and Surface Chemistry ,Titration ,0210 nano-technology ,0105 earth and related environmental sciences ,Entropy (order and disorder) - Abstract
Specific ion effects on the aggregation behavior of a reference aquatic natural organic matter (NOM), Suwannee River NOM (SRNOM), were investigated using kinetic, titration, calorimetric, and surface tension methods. Monovalent cations induced structural compacting of SRNOM, but not its aggregation. Their ability to induce structural compacting follows the order: Cs+ > Rb+ > K+ > Na+ > Li+. Divalent cations except Mg2+ can readily induce SRNOM aggregation. Their critical coagulation concentrations (CCC) follow the order: CCCSr > CCCCa > CCCBa. Electrokinetic, titration, and calorimetric data suggest that monovalent cations have weak interactions with SRNOM, while divalent cations strongly interact with SRNOM. Overall, the cation specificity in aggregation is determined by cation-NOM interactions and their ability to modulate surface tension. Specific ion effects of monovalent cations correlate to their hydration free energy, while that of divalent cations correlate to the ratio of the hydration entropy of cation to the enthalpy change of cation-NOM interactions. The cation specificity is consistent with the extended Derjaguin-Landau-Verwey-Overbeek theory, and the intermolecular interaction energy is dominated by the Lewis acid-base interactions. Our results suggest that specific cations should be targeted to predict or manipulate intermolecular interactions of aquatic NOM in natural and engineered settings.
- Published
- 2019
19. Impact of the initial hydrophilic ratio on black carbon aerosols in the Arctic
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Yunman Han, Bo Fu, Shu Tao, Dongqiang Zhu, Xuhui Wang, Shushi Peng, and Bengang Li
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Aerosols ,Air Pollutants ,Environmental Engineering ,Soot ,Environmental Chemistry ,Pollution ,Waste Management and Disposal ,Carbon ,Environmental Monitoring - Abstract
Black carbon (BC) contributes to patterns of Arctic warming, yet the initial hydrophilic ratio (IHR) of BC emitted from various sources and its impact on Arctic BC remain uncertain. With the use of a tagged tracer method of BC implemented in the global chemistry transport model GEOS-Chem, IHRs were partitioned into 7 BC combustion source categories according to the PKU-BC-v2 emission inventory. The results show that as the IHR increased, the concentration of BC decreased globally. The impact on Arctic BC was mainly reflected in the vertical profile and the burden rather than at the surface. Specifically, the greatest impact of IHR on Arctic BC appeared in summer, with the largest perturbation appearing at an altitude of approximately 600 hPa, reaching 8%. This change in BC vertical profile was mainly caused by the IHR change of wildfire combustion in Russia (44%) and Canada (51%), and the emissions from these two regions were also the two most important contributors to the BC concentration and burden in the middle and lower Arctic atmosphere in summer. In the other three seasons, anthropogenic combustion sources (oil, coal, and biomass) in East Asia, Russia, and Europe accounted for 19-40%, 14-28%, and 7-23%, respectively, of the monthly BC burden. Emissions from Russia were the most important contributor (27-43%) to the monthly BC surface concentration. Due to the large adjustment in IHR from 20% to 70%, biomass burning in Europe was shown to be the dominant contributor causing both burden (39%) and surface concentration (88%) changes in all seasons except summer.
- Published
- 2021
20. Source and formation process impact the chemodiversity of rainwater dissolved organic matter along the Yangtze River Basin in summer
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Shuang Chen, Qiaorong Xie, Sihui Su, Libin Wu, Shujun Zhong, Zhimin Zhang, Chao Ma, Yulin Qi, Wei Hu, Junjun Deng, Lujie Ren, Dongqiang Zhu, Qingjun Guo, Cong-Qiang Liu, Kyoung-Soon Jang, and Pingqing Fu
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China ,Environmental Engineering ,Rivers ,Ecological Modeling ,Humans ,Seasons ,Dissolved Organic Matter ,Pollution ,Waste Management and Disposal ,Fluorescence ,Water Science and Technology ,Civil and Structural Engineering ,Aged - Abstract
Rainwater dissolved organic matter (DOM) plays an important role in the biogeochemical cycle and evolution of organic matter in the land-atmosphere interface. To better understand their sources and molecular composition in the atmosphere, rainwater samples were collected at six different locations along the Yangtze River Basin. Based on the application of a combined approach including excitation-emission matrix (EEM) fluorescence and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), various sources (terrestrial, anthropogenic, and autochthonous sources) of rainwater DOM were revealed. Results show that the derivatives of biogenic volatile organic compounds were widely distributed and contributed to rainwater DOM along the Yangtze River Basin. In the up-river city Batang, rainwater DOM was affected by the long-range atmospheric transport due to the Indian summer monsoon. Lijiang, a city on the southeastern edge of Tibetan plateau, was related to strong local biomass burning. The industrial cities of Panzhihua and Luzhou showed large differences in organic composition due to distinct industrial types. Fuling, a district in Chongqing Municipality, was significantly contributed by aged organics from biomass burning. While rainwater DOM in Shanghai, a coastal megacity, contained a high fraction of sea spray organics. Further, more than 70% of rainwater DOM molecules are associated with 36 typical transformation mechanisms during rainwater-scavenging processes, e.g., oxidation reactions, dealkylation and decarboxylation. Our study demonstrates that local natural and anthropogenic emissions and climatic conditions strongly shaped the chemodiversity and possible precursor-product pairs of rainwater DOM along the Yangtze River Basin, which helps to better understand the biogeochemical cycles of organic matter in a large-scale watershed under the influence of human activities.
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- 2021
21. In situ fabricated porous carbon coating derived from metal-organic frameworks for highly selective solid-phase microextraction
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He Yuhao, Heyun Fu, Wei Fangxue, Dongqiang Zhu, Shourong Zheng, Xiaolei Qu, and Zhaoyi Xu
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Detection limit ,Carbonization ,Chemistry ,fungi ,Extraction (chemistry) ,engineering.material ,Solid-phase microextraction ,Molecular sieve ,Biochemistry ,Analytical Chemistry ,Coating ,Chemical engineering ,Dissolved organic carbon ,engineering ,Environmental Chemistry ,Fiber ,Spectroscopy - Abstract
Solid-phase microextraction (SPME) has been widely used in analysis of trace organic contaminants in environmental samples. Stable, efficient, and selective fiber coating is the key to the development of SPME technique. In this study, an in situ fabricated porous carbon coating that derived from metal-organic frameworks (MOFs) was introduced for solid-phase microextraction (SPME). The carbon coating (denoted as MOF-74-C) was prepared by the direct carbonization of a MOF-74 coating that was in situ grown on stainless steel wire, which was explored for the extraction of odorous organic contaminants for the first time. MOF-74-C coated fiber showed high extraction efficiency (1.1–16.0 times larger than commercial fibers for most tested analytes under the same extraction conditions), as well as good thermal and chemical stability. Furthermore, it can selectively extract the analytes with the simultaneous exclusion of coexisting dissolved organic matter due to the molecular sieve effect invoked by the well-defined micropores. The method based on MOF-74-C coating for analysis of odorants afforded wide linear ranges (more than two orders of magnitude), low detection limits (below the odor threshold concentrations), good intra- and inter-day accuracies (90.1–107.3%) and precisions (relative standard deviations/RSDs below 9.4%) and satisfactory reproducibility (RSDs below 8.7%). Finally, the MOF-74-C coated fiber was successfully applied for the SPME analysis of odorants in real water samples. These results highlight the great potential of in situ fabricated porous carbons derived from MOFs for SPME applications.
- Published
- 2019
22. Comparing electron donating/accepting capacities (EDC/EAC) between crop residue-derived dissolved black carbon and standard humic substances
- Author
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Mingquan Yan, Heyun Fu, Xiaolei Qu, Xiaojian Zheng, Yafang Liu, Dongqiang Zhu, and Shuzhen Zhang
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Crop residue ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Chemistry ,Uv vis absorption ,dBc ,Electrons ,Carbon black ,010501 environmental sciences ,Electrochemistry ,Positive correlation ,01 natural sciences ,Pollution ,Electron Transport ,Electron transfer ,Models, Chemical ,Soot ,Dissolved organic carbon ,Environmental Chemistry ,Waste Management and Disposal ,Humic Substances ,0105 earth and related environmental sciences ,Nuclear chemistry - Abstract
Although dissolved black carbon (DBC) is an important component of dissolved organic matter (DOM), little is known about the electron transfer properties of DBC and their correlation with the structural properties. This study determined the electron donating/accepting capacities (EDC/EAC) of six DBC collected from water extracts of black carbon derived by pyrolyzing crop residues (soybean, wheat, rice, sorghum, peanut, and corn) using an electrochemical approach, along with their chemical and spectroscopic properties. The EDC of the tested DBC ranged from 2.42 to 7.10 mmole-(gC)−1and was generally much higher than the EDC (1.31–3.78 mmole-(gC)−1) of the four standard dissolved humic substances (DHS). In contrast, with the exception of the sorghum DBC, the EAC of all DBC (0.40–0.81 mmole-(gC)−1) was apparently lower than the EAC of DHS (0.87–1.68 mmole-(gC)−1). For the whole pool of DBC and DHS, a strong positive correlation (r = 0.94, P Capsule: Dissolved black carbon (DBC) has significantly different electron-donating/accepting capacities (EDC/EAC) from humic substances.
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- 2019
23. Efficient removal of ionic liquids from aqueous media using ZSM-5 zeolites: A tunable mechanism combining micropore filling and electrostatic interaction
- Author
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Liu Hui, Heyun Fu, Xiaolei Qu, Zhaoyi Xu, Shourong Zheng, Dongqiang Zhu, Ling Zhang, and Weng Xin
- Subjects
Materials science ,Aqueous two-phase system ,02 engineering and technology ,General Chemistry ,Microporous material ,Mesoporous silica ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemical engineering ,Mechanics of Materials ,Ionic liquid ,General Materials Science ,ZSM-5 ,0210 nano-technology ,Zeolite ,Porous medium - Abstract
Removal of aqueous phase ionic liquid (IL) compounds has drawn increasing attention due to their potential human health and ecological impact. This study addresses the contribution of various adsorbent-adsorbate interactions at solid/liquid interface and how these interactions can be manipulated controlling the adsorption of ILs onto zeolites, with a particular focus on hydrophobic partition and electrostatic interaction. For this purpose, a variety of zeolites with different pore structure and aluminum contents were used to probe the adsorption mechanisms for the removal of imidazolium-based ILs. Nonporous SiO2, ordered mesoporous silica MCM-41 and SBA-15 were used for comparison. Batch adsorption results along with characterization of the adsorbents indicate that micropore filling effect is a common mechanism for the adsorption of ILs on different types of zeolites. Hydrophobic partition also contributes to the IL adsorption on zeolites with low or null aluminum content. Aluminum-containing zeolites (ZSM-5-11 and ZSM-5-36) with negatively charged framework have much higher adsorption capacities than aluminum-free zeolites owing to the additional electrostatic attractive interaction. Moreover, IL saturated ZSM-5-11 can be regenerated and reused, and displayed stable adsorption behavior for ten consecutive adsorption-regeneration cycles, highlighting the potential of ZSM-5 zeolite for practical applications.
- Published
- 2019
24. Prediction of hydrophobic organic compound partition to algal organic matter through the growth cycle of Microcystis aeruginosa
- Author
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Heyun Fu, Peiyun Wei, Dongqiang Zhu, Xiaolei Qu, and Zhaoyi Xu
- Subjects
chemistry.chemical_classification ,Microcystis ,biology ,Health, Toxicology and Mutagenesis ,Water ,General Medicine ,Fractionation ,Toxicology ,biology.organism_classification ,Pollution ,Organic compound ,Partition coefficient ,chemistry ,Algae ,Environmental chemistry ,Dissolved organic carbon ,otorhinolaryngologic diseases ,Organic matter ,Microcystis aeruginosa ,Organic Chemicals ,Polycyclic Aromatic Hydrocarbons ,Eutrophication ,Hydrophobic and Hydrophilic Interactions - Abstract
Algal organic matter (AOM) is an important source for the dissolved organic matter (DOM) pool in aquatic systems, particularly in eutrophic waters. In this study, we reported the dynamic pattern of AOM hydrophobicity during the growth cycle of Microcystis aeruginosa using the partition coefficients of AOM in the aqueous two-phase system (KATPS) as a simple quantitative measure. AOM hydrophobicity had significant and non-monotonic changes during the growth cycle. It increased in the lag and early exponential phases, then decreased in the late exponential and stationary phases, and rebounded in the decline phase. AOM hydrophobicity determined using the resin fractionation, SUVA254, and nuclear magnetic resonance methods shared similar non-monotonic pattern. Nevertheless, the correlations among these indicators were poor. The partition behavior of polycyclic aromatic hydrocarbons and chlorobenzenes to AOM was assessed based the KATPS dataset and the two-phase system (TPS) model. The TPS model showed good prediction power for the partition behavior of AOM with an RMSE of 0.23, suggesting that it was applicable to AOM from Microcystis aeruginosa. Our results indicate that algae activity will influence the overall hydrophobicity of the DOM pool depending on the growth phase, resulting in changes in the bioavailability of hydrophobic organic compounds in aquatic systems.
- Published
- 2021
25. Sulfide induces physical damages and chemical transformation of microplastics via radical oxidation and sulfide addition
- Author
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Mengting Zhao, Wei Chen, Xinlei Liu, Tong Zhang, Xinlin Yang, and Dongqiang Zhu
- Subjects
Chemical transformation ,Microplastics ,Environmental Engineering ,Sulfide ,Radical ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Sulfides ,Photochemistry ,01 natural sciences ,Water Purification ,chemistry.chemical_compound ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,chemistry.chemical_classification ,Quenching (fluorescence) ,Ecological Modeling ,Polymer ,Polyethylene ,Pollution ,020801 environmental engineering ,chemistry ,Polystyrene ,Oxidation-Reduction ,Plastics ,Water Pollutants, Chemical - Abstract
Transformation of microplastics in aquatic environments and engineered systems (e.g., wastewater treatment plants) significantly affects their transport, fate and effects. Here, we present the counterintuitive finding that sulfide, a prevalent nucleophile and reductant, can result in oxidation of microplastics, in addition to sulfide addition. Treating four model microplastics (thermoplastic polyurethane, polystyrene, polyethylene terephthalate and polyethylene) with 0.1 mM sulfide in a Tris-buffer solution (pH 7.2, 25 °C) resulted in physical damages (embrittlement and cracking) and chemical transformation (increased O/C ratio and formation of C–S bonds) of the materials. Pre-aging of the microplastics with O3 or UV treatment had varied effects on their reactivities toward sulfide, depending on the specific structural and surface chemistry properties of the polymers. Electron paramagnetic resonance and radical trapping/quenching experiments showed that sulfide underwent spontaneous oxidation to form •OH radicals, which acted as the primary oxidant to attack the carbon atoms in the polymer chains, leading to surface oxidation and chain scission. Notably, sulfide addition, verified with X-ray photoelectron spectroscopy and 13C-nuclear magnetic resonance spectroscopy analyses, likely contributed to the physicochemical transformation of microplastics together with radical oxidation in a synergistic manner. The findings unravel an important transformation route (and a potential source) of microplastics in the environment.
- Published
- 2021
26. Global mapping of crop-specific emission factors highlights hotspots of nitrous oxide mitigation
- Author
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Dongqiang Zhu, Hanqin Tian, Robert B. Jackson, Qihui Wang, Eric A. Davidson, Philippe Ciais, Josep G. Canadell, David R. Kanter, Wulahati Adalibieke, Alexander F. Bouwman, Yan Bo, Feng Zhou, Xiaoying Zhan, Francesco N. Tubiello, Xunhua Zheng, Nathaniel D. Mueller, Xiaoyue Niu, Xiaoqing Cui, Xiaotang Ju, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University [Beijing], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CONV-0003,CLAND,CLAND : Changement climatique et usage des terres(2016)
- Subjects
010504 meteorology & atmospheric sciences ,Humid subtropical climate ,Atmospheric sciences ,01 natural sciences ,Crop ,03 medical and health sciences ,chemistry.chemical_compound ,Crop production ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Management practices ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0105 earth and related environmental sciences ,2. Zero hunger ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,0303 health sciences ,Edaphic ,Nitrous oxide ,15. Life on land ,chemistry ,13. Climate action ,Georeference ,Environmental science ,Animal Science and Zoology ,Agronomy and Crop Science ,Food Science - Abstract
Mitigating soil nitrous oxide (N2O) emissions is essential for staying below a 2 °C warming threshold. However, accurate assessments of mitigation potential are limited by uncertainty and variability in direct emission factors (EFs). To assess where and why EFs differ, we created high-resolution maps of crop-specific EFs based on 1,507 georeferenced field observations. Here, using a data-driven approach, we show that EFs vary by two orders of magnitude over space. At global and regional scales, such variation is primarily driven by climatic and edaphic factors rather than the well-recognized management practices. Combining spatially explicit EFs with N surplus information, we conclude that global mitigation potential without compromising crop production is 30% (95% confidence interval, 17–53%) of direct soil emissions of N2O, equivalent to the entire direct soil emissions of China and the United States combined. Two-thirds (65%) of the mitigation potential could be achieved on one-fifth of the global harvested area, mainly located in humid subtropical climates and across gleysols and acrisols. These findings highlight the value of a targeted policy approach on global hotspots that could deliver large N2O mitigation as well as environmental and food co-benefits. Estimating the global cropland N2O mitigation potential is limited by the uncertainty and variability of direct emission factors (EFs). Here, using a data-driven approach with 1,507 chamber-based field observations of EFs, the study shows that EF variation is primarily driven by climatic and edaphic factors. Two-thirds of the mitigation potential could be achieved on one-fifth of the global harvested area, mainly located in humid subtropical climates and across gleysols and acrisols.
- Published
- 2021
27. Variations of root-associated bacterial cooccurrence relationships in paddy soils under chlorantraniliprole (CAP) stress
- Author
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Yi-Fan Qin, Dongqiang Zhu, Feng Zhou, Yi-Long Li, Rui-Lin Wu, Chao-Nan Wang, and Fu-Liu Xu
- Subjects
Rhizosphere ,Developmental stage ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Ecology ,Agricultural ecosystems ,010501 environmental sciences ,Biology ,01 natural sciences ,Pollution ,Plant Roots ,Plant development ,Soil ,Soil water ,Environmental Chemistry ,Paddy soils ,Ecological risk ,ortho-Aminobenzoates ,Microbiome ,Waste Management and Disposal ,Soil Microbiology ,0105 earth and related environmental sciences - Abstract
Root-associated microbiomes are beneficial for plant development and health. However, the assembly of root-associated bacterial communities and their feedback under chlorantraniliprole (CAP) stress are unclear. This study investigated the response of root-associated bacterial microbiota to CAP dosage during the two developmental phases of rice. The results showed that CAP application had little effect on the bacterial diversity of bulk and rhizosphere soils, whereas that of the endosphere samples demonstrated a large variability. Moreover, the CAP stress exhibited less influence than the plant compartment and developmental stage contributing to microbiome variation. The core bacterial co-occurrence relationships also changed with the CAP application, especially, in the endosphere of the roots. These results further elucidate the impacts of CAP application on root-associated bacterial communities in intensive agricultural ecosystems and provide new insights for CAP ecological risk assessments.
- Published
- 2020
28. Surface quinone-induced formation of aqueous reactive sulfur species controls pine wood biochar-mediated reductive dechlorination of hexachloroethane by sulfide
- Author
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Dongqiang Zhu, Shujun Yin, and Chenhui Wei
- Subjects
010504 meteorology & atmospheric sciences ,Sulfide ,Inorganic chemistry ,chemistry.chemical_element ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,Sulfides ,01 natural sciences ,Redox ,chemistry.chemical_compound ,Biochar ,Reductive dechlorination ,Hydrocarbons, Chlorinated ,Environmental Chemistry ,Hexachloroethane ,Polysulfide ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Ethane ,Aqueous solution ,Chemistry ,Nanotubes, Carbon ,Public Health, Environmental and Occupational Health ,Quinones ,General Medicine ,Pinus ,Sulfur ,Charcoal ,Oxidation-Reduction - Abstract
Understanding the mechanisms controlling the redox transformation of organic contaminants mediated by biochar is of great significance for application of biochar in remediation of contaminated soils and sediments. Here we investigated the mediation effect of a pine wood-derived biochar (P-char) in comparison with multiwalled carbon nanotubes (MCNTs) and graphite on the reductive dechlorination of hexachloroethane by sulfide. Upon normalization of the mediator's surface area, the reduction rate of hexachloroethane follows an order of P-char < MCNTs < graphite. Aqueous polysulfides and polysulfide free radicals were readily produced by reacting sulfide only with P-char, and the supernatant separated from the reaction system could account for 83.4% of the pseudo-kinetic rate constant of hexachloroethane mediated by P-char. In contrast, MCNTs and graphite had weak abilities to produce reactive sulfur species, and the supernatant exhibited very low reduction capability (
- Published
- 2020
29. Dissolved Black Carbon Facilitates Photoreduction of Hg(II) to Hg(0) and Reduces Mercury Uptake by Lettuce (
- Author
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Langlang, Li, Xuejun, Wang, Heyun, Fu, Xiaolei, Qu, Jiubin, Chen, Shu, Tao, and Dongqiang, Zhu
- Subjects
Soil ,Soot ,Soil Pollutants ,Oryza ,Mercury ,Lettuce ,Humic Substances - Abstract
Here, we investigated the photoreduction of Hg(II) (Hg(NO
- Published
- 2020
30. Assessment of Bioavailability of Biochar-Sorbed Tetracycline to
- Author
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Bingyu, Wang, Yingjie, Zhang, Dongqiang, Zhu, and Hui, Li
- Subjects
Soil ,Charcoal ,Escherichia coli ,Tetracycline Resistance ,Biological Availability ,Humans ,Drug Resistance, Microbial ,Tetracycline ,Anti-Bacterial Agents - Abstract
Human overuse and misuse of antibiotics have caused the wide dissemination of antibiotics in the environment, which has promoted the development and proliferation of antibiotic resistance genes (ARGs) in soils. Biochar (BC) with strong sorption affinity to many antibiotics is considered to sequester antibiotics and hence mitigate their impacts to bacterial communities in soils. However, little is known about whether BC-sorbed antibiotics are bioavailable and exert selective pressure on soil bacteria. In this study, we probed the bioavailability of tetracycline sorbed by BCs prepared from rice-, wheat-, maize-, and bean-straw feedstock using
- Published
- 2020
31. Mechanisms for sulfide-induced nitrobenzene reduction mediated by a variety of different carbonaceous materials: Graphitized carbon-facilitated electron transfer versus quinone-facilitated formation of reactive sulfur species
- Author
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Dongqiang Zhu, Chenhui Wei, and Shujun Yin
- Subjects
Environmental Engineering ,Sulfide ,Inorganic chemistry ,chemistry.chemical_element ,Electrons ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,Sulfides ,01 natural sciences ,Redox ,Nitrobenzene ,chemistry.chemical_compound ,Reaction rate constant ,Graphite ,Waste Management and Disposal ,Polysulfide ,Nitrobenzenes ,0105 earth and related environmental sciences ,Water Science and Technology ,chemistry.chemical_classification ,Quinones ,04 agricultural and veterinary sciences ,Carbon black ,Pollution ,chemistry ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Carbon ,Oxidation-Reduction ,Sulfur - Abstract
Although it has long been known that carbonaceous materials (CMs) can facilitate the reduction of organic contaminants by sulfide, the underlying mechanisms and controlling factors, particularly the surface property dependence, are not well understood. Here, sulfide-induced nitrobenzene reduction was explored as a model reaction to compare the mediation efficiency of a variety of CMs, including rice straw-derived black carbon (R-BC) and pine wood-derived black carbon (P-BC), a commercial activated carbon (AC), multi-walled carbon nanotube (MCNT), and graphite. Given the same load (250 mg L-1 ), the observed pseudo-first-order rate constant (kobs ) of nitrobenzene reduction was ordered as AC > R-BC > MCNT > P-BC > graphite. The surface area-normalized rate constant (kSN ) was ordered as R-BC > graphite > MCNT > AC > P-BC. Neither the kobs nor the kSN followed the order of mediator's electron conductivity (graphite > MCNT > AC > P-BC > R-BC). For the low-graphitized R-BC and P-BC, increasing surface oxygen content by HNO3 oxidation enhanced nitrobenzene reduction, whereas decreasing the content by NaBH4 reduction impeded the reaction. Opposite trends were observed with the high-graphitized AC, MCNT, and graphite. The quinone moieties of low-graphitized CMs were found to facilitate nitrobenzene reduction by serving as one-electron acceptors to generate reactive reducing sulfur species (polysulfides and polysulfide free radicals) from sulfide. In contrast, the surface oxygen groups of high-graphitized CMs suppressed the reaction by lowering the electron conductivity. These results demonstrate that the types of CMs and their surface chemistry properties are key determinants in mediating redox transformation of organic contaminants.
- Published
- 2020
32. Response for Anonymous Referee #1
- Author
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Dongqiang Zhu
- Published
- 2020
33. Response for Anonymous Referee #2
- Author
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Dongqiang Zhu
- Published
- 2020
34. Role of Extracellular Polymeric Substances in Microbial Reduction of Arsenate to Arsenite by
- Author
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Xinwei, Zhou, Fuxing, Kang, Xiaolei, Qu, Heyun, Fu, Pedro J J, Alvarez, Shu, Tao, and Dongqiang, Zhu
- Subjects
Arsenites ,Extracellular Polymeric Substance Matrix ,Multienzyme Complexes ,Arsenite Transporting ATPases ,Escherichia coli ,Arsenates ,Ion Pumps ,Arsenic ,Bacillus subtilis - Abstract
We show that arsenate can be readily reduced to arsenite on cell surfaces of common bacteria (
- Published
- 2020
35. Supplementary material to 'An investigation on hygroscopic properties of 15 black carbon (BC) from different carbon sources: Roles of organic and inorganic components'
- Author
-
Minli Wang, Yiqun Chen, Heyun Fu, Xiaolei Qu, Bengang Li, Shu Tao, and Dongqiang Zhu
- Published
- 2020
36. An investigation on hygroscopic properties of 15 black carbon (BC) from different carbon sources: Roles of organic and inorganic components
- Author
-
Yiqun Chen, Dongqiang Zhu, Xiaolei Qu, Heyun Fu, Shu Tao, Bengang Li, and Minli Wang
- Subjects
Total organic carbon ,Chemistry ,Environmental chemistry ,Vapour pressure of water ,Humidity ,Gravimetric analysis ,chemistry.chemical_element ,Relative humidity ,Carbon black ,Carbon ,Water vapor - Abstract
The hygroscopic behavior of black carbon (BC) has a significant impact on global and regional climate change. However, the mechanism and factors controlling the hygroscopicity of BC from different carbon sources are not well understood. Here, we systematically measured the equilibrium and kinetics of water uptake by 15 different BC (10 herb-derived BC, 2 wood-derived BC, and 3 soot) using gravimetric water vapor sorption method combined with in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). In the gravimetric analysis, the sorption/desorption equilibrium isotherms were measured under continuous-stepwise water vapor pressure conditions, while the kinetics was measured at a variety of humidity levels obtained by different saturated aqueous salt solutions. The equilibrium water uptake of the BC pool at high relative humidity (> 80 %) positively correlated to the dissolved mineral content (0.01–13.0 wt %) (R2 = 0.86, P = 0.0001) as well as the content of the thermogravimetrically analyzed organic carbon (OCTGA, 4.48–15.25 wt %) (R2 = 0.52, P = 0.002) and the alkali-extracted organic carbon (OCAE, 0.14–8.39 wt %) (R2 = 0.80, P = 0.0001). In contrast, no positive correlation was obtained with the content of total organic carbon or elemental carbon. Among the major soluble ionic constituents, chloride and ammonium were each correlated with the equilibrium water uptake at high relative humidity. Compared with the herbal BC and soot, the woody BC had much lower equilibrium water uptake, especially at high relative humidity, likely due to the very low dissolved material content and OC content. The DRIFTS analysis provided generally consistent results at low relative humidity. The kinetics of water uptake (measured by pseudo-second order rate constant) correlated to the content of OCTGA and OCAE as well as the content of chloride and ammonium at low relative humidity (33 %), but to the porosity of bulk BC at high relative humidity (94 %). This was the first study to show that BC of different types and sources has greatly varying hygroscopic properties.
- Published
- 2020
37. Mechanisms and Factors Controlling Hygroscopic Properties of Black Carbon (BC) from Different Carbon Sources Under Different Humidity Conditions
- Author
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Minli Wang, Yiqun Chen, Heyun Fu, Xiaolei Qu, Bengang Li, Shu Tao, and Dongqiang Zhu
- Published
- 2020
38. Revisiting the proportion of clean household energy users in rural China by accounting for energy stacking
- Author
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Guofeng Shen, Ran Xing, Yousong Zhou, Xiaoqiao Jiao, Zhihan Luo, Rui Xiong, Wenxuan Huang, Yanlin Tian, Yuanchen Chen, Wei Du, Huizhong Shen, Hefa Cheng, Dongqiang Zhu, and Shu Tao
- Published
- 2022
39. Enhanced adsorption of bisphenol A, tylosin, and tetracycline from aqueous solution to nitrogen-doped multiwall carbon nanotubes via cation-π and π-π electron-donor-acceptor (EDA) interactions
- Author
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Linzi Zuo, Langsha Yi, Dongqiang Zhu, Heyun Fu, Xiaolei Qu, Shourong Zheng, Hui Li, Zhaoyi Xu, Chenhui Wei, and Yong Guo
- Subjects
Environmental Engineering ,010504 meteorology & atmospheric sciences ,Nitrogen ,Heteroatom ,chemistry.chemical_element ,Electron donor ,Electrons ,Carbon nanotube ,010501 environmental sciences ,Photochemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Adsorption ,Phenols ,law ,Cations ,Environmental Chemistry ,Moiety ,Molecule ,Benzhydryl Compounds ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Aqueous solution ,Chemistry ,Nanotubes, Carbon ,Pollution ,Tylosin ,Carbon - Abstract
Doping heteroatoms in carbon nanotubes can substantially enhance the electronic polarizability of the carbon surface and thus may facilitate adsorptive interactions of organic contaminants. Here, the adsorption isotherms of three polar/ionizable emerging organic contaminants, bisphenol A, tylosin, and tetracycline from aqueous solutions to synthesized heteroatom nitrogen-doped multiwall carbon nanotubes (N-MCNT) were compared with those to commercial non-doped multiwall carbon nanotubes (MCNT) at pH ~ 6. N-MCNT exhibited much stronger adsorption (3–4 folds higher sorption distribution coefficients, Kd) towards the three adsorbates than MCNT. The hydroxyl group-substituted bisphenol A molecule is rich in π-electrons and thus interacts with the polarized π-electron-depleted N-heterocyclic aromatic ring on N-MCNT via π-π electron-donor-acceptor (EDA) interaction, whereas the protonated amino group and enone groups in the tylosin molecule are deficient in electrons and interact with the neighboring π-electron-rich aromatic ring on N-MCNT via cation-π and π-π EDA interactions, respectively. The tetracycline molecule contains both electron-rich moiety (phenol ring) and electron-depleted moieties (protonated amino group and enone groups), which interact with the corresponding π-electron-acceptor/donor sites on N-MCNT. The proposed adsorption mechanisms were tested by the effects of ionic strength (NaCl or CaCl2), co-present Cu2+ ion, and changing pH on adsorption, and further by the adsorption behavior of a model organic cation (tetraethylamine). These results indicate that enhanced adsorption of emerging organic contaminants to carbon nanotubes can be achieved by doping with heterocyclic nitrogen atoms to facilitate specific EDA interactions. Capsule: Nitrogen-doped multiwall carbon nanotubes exhibit enhanced adsorptive removal of bisphenol A, tylosin, and tetracycline from aqueous solutions.
- Published
- 2019
40. Oxidized template-synthesized mesoporous carbon with pH-dependent adsorption activity: A promising adsorbent for removal of hydrophilic ionic liquid
- Author
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Zhaoyi Xu, Dongqiang Zhu, Ling Zhang, Xiaolei Qu, Pedro J. J. Alvarez, Heyun Fu, Shourong Zheng, and Cao Wugang
- Subjects
General Physics and Astronomy ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Microporous material ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Chloride ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Adsorption ,chemistry ,Nitric acid ,Ionic liquid ,medicine ,Titration ,Freundlich equation ,0210 nano-technology ,0105 earth and related environmental sciences ,Activated carbon ,medicine.drug ,Nuclear chemistry - Abstract
Aiming to remove ionic liquid pollutants from water, an ordered mesoporous carbon CMK-3 (OMC) was prepared and modified by oxidation with nitric acid. A commercial microporous activated carbon adsorbent, Filtrasorb-300 (AC), was used as benchmark. Boehm titration showed that oxidized OMC had a substantially higher oxygen content than oxidized AC. Adsorption of the hydrophilic imidazolium-based ionic liquid 1-Butyl-3-methylimidazolium chloride ([Bmim]Cl) on OMC and AC was well-described by the Freundlich isotherm model. Surface oxidation markedly enhanced [Bmim]Cl adsorption by both OMC and AC. Nevertheless, [Bmim]Cl adsorption was much higher on oxidized OMC than on oxidized AC. Increasing pH had negligible influence on [Bmim]Cl adsorption on pristine OMC, but enhanced adsorption on oxidized OMC. Regeneration tests showed stable performance of oxidized OMC over five adsorption-desorption cycles. Thus, oxidized OMC can be a highly effective adsorbent for the removal of hydrophilic ionic liquids from water.
- Published
- 2018
41. Polystyrene Nanoplastics-Enhanced Contaminant Transport: Role of Irreversible Adsorption in Glassy Polymeric Domain
- Author
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Rong Ji, Wei Chen, Yu Qi, Tianjiao Xia, Jin Liu, Yini Ma, Xiaoran Guo, Dongqiang Zhu, and Yao Yao
- Subjects
Pollutant ,Polymers ,Chemistry ,Potential risk ,Irreversible adsorption ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Domain (software engineering) ,Soil ,chemistry.chemical_compound ,Chemical engineering ,Polystyrenes ,Soil Pollutants ,Environmental Chemistry ,Adsorption ,Polystyrene ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
Nanoplastics (NPs) are becoming an emerging pollutant of global concern. A potential risk is that NPs may serve as carriers to increase the spreading of coexisting contaminants. In this study, we examined the effects of polystyrene nanoplastics (PSNPs, 100 nm), used as a model NP, on the transport of five organic contaminants of different polarity in saturated soil. The presence of low concentrations of PSNPs significantly enhanced the transport of nonpolar (pyrene) and weakly polar (2,2',4,4'-tetrabromodiphenyl ether) compounds, but had essentially no effects on the transport of three polar compounds (bisphenol A, bisphenol F, and 4-nonylphenol). The strikingly different effects of NPs on the transport of nonpolar/weakly polar versus polar contaminants could not be explained with different adsorption affinities, but was consistent with the polarity-dependent extents of desorption hysteresis. Notably, desorption hysteresis was only observed for nonpolar/weakly polar contaminants, likely because nonpolar compounds tended to adsorb in the inner matrices of glassy polymeric structure of polystyrene (resulting in physical entrapment of adsorbates), whereas polar compounds favored surface adsorption. This hypothesis was verified with supplemental adsorption and desorption experiments of pyrene and 4-nonylphenol using a dense, glassy polystyrene polymer and a flexible, rubbery polyethylene polymer. Overall, the findings of this study underscore the potentially significant environmental implication of NPs as contaminant carriers.
- Published
- 2018
42. Aggregation Behavior of Dissolved Black Carbon: Implications for Vertical Mass Flux and Fractionation in Aquatic Systems
- Author
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Xiaolei Qu, Qilin Li, Chenhui Wei, Fanchao Xu, Qingqing Zeng, Dongqiang Zhu, Xuening Li, and Pedro J. J. Alvarez
- Subjects
Mass flux ,chemistry.chemical_classification ,010504 meteorology & atmospheric sciences ,Chemistry ,Oceans and Seas ,Analytical chemistry ,dBc ,General Chemistry ,Fractionation ,Carbon black ,010501 environmental sciences ,01 natural sciences ,Carbon ,Divalent ,Molecular Weight ,Colloid ,Flux (metallurgy) ,Soot ,Biochar ,Environmental Chemistry ,Humic Substances ,0105 earth and related environmental sciences - Abstract
The fluvial export of dissolved black carbon (DBC) is a major land-ocean flux in the global black carbon cycle, affecting the size of refractory carbon pool in the oceans. The aggregation behavior of DBC is a significant determinant of its transport and vertical mass flux. In this study, the aggregation kinetics and interaction energy of DBC leached from biochar were investigated. DBC was mainly stabilized by hydration force and underwent structural compacting in divalent cation solutions. Na+ and Mg2+ had limited impact on the colloidal stability of DBC due to the strong hydration of these cations. Ca2+ and Ba2+ readily destabilized DBC by forming inner-sphere complexes, reducing its hydrophilicity. Consistently, charge reversal of DBC was observed with high concentrations of Ca2+ and Ba2+. Simulated sunlight exposure led to photo-oxidation of DBC, increasing its colloidal stability. DBC behaved nonconservatively in laboratory mixing experiments using estuary water samples due to aggregation/sedimentatio...
- Published
- 2017
43. Removal of aqueous Pb(II) by adsorption on Al 2 O 3 -pillared layered MnO 2
- Author
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Shourong Zheng, Dongqiang Zhu, Ling Zhang, Liqin Gu, Jingya Sun, Haipeng Zhang, Zhaoyi Xu, and Haiqin Wan
- Subjects
chemistry.chemical_classification ,Sorbent ,Aqueous solution ,Chemistry ,Metal ions in aqueous solution ,Inorganic chemistry ,Kinetics ,General Physics and Astronomy ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Adsorption ,X-ray photoelectron spectroscopy ,Humic acid ,0210 nano-technology ,BET theory - Abstract
In the present study, Al 2 O 3 -pillared layered MnO 2 (p-MnO 2 ) was synthesized using δ-MnO 2 as precursor and Pb(II) adsorption on p-MnO 2 and δ-MnO 2 was investigated. To clarify the adsorption mechanism, Al 2 O 3 was also prepared as an additional sorbent. The adsorbents were characterized by X-ray fluorescence analysis, powder X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and N 2 adsorption-desorption. Results showed that in comparison with pristine δ-MnO 2 , Al 2 O 3 pillaring led to increased BET surface area of 166.3 m 2 g −1 and enlarged basal spacing of 0.85 nm. Accordingly, p-MnO 2 exhibited a higher adsorption capacity of Pb(II) than δ-MnO 2 . The adsorption isotherms of Pb(II) on δ-MnO 2 and Al 2 O 3 pillar fitted well to the Freundlich model, while the adsorption isotherm of Pb(II) on p-MnO 2 could be well described using a dual-adsorption model, attributed to Pb(II) adsorption on both δ-MnO 2 and Al 2 O 3 . Additionally, Pb(II) adsorption on δ-MnO 2 and p-MnO 2 followed the pseudo second-order kinetics, and a lower adsorption rate was observed on p-MnO 2 than δ-MnO 2 . The Pb(II) adsorption capacity of p-MnO 2 increased with solution pH and co-existing cation concentration, and the presence of dissolved humic acid (10.2 mg L −1 ) did not markedly impact Pb(II) adsorption. p-MnO 2 also displayed good adsorption capacities for aqueous Cu(II) and Cd(II). Findings in this study indicate that p-MnO 2 could be used as a highly effective adsorbent for heavy metal ions removal in water.
- Published
- 2017
44. Sunlight Promotes Fast Release of Hazardous Cadmium from Widely-Used Commercial Cadmium Pigment
- Author
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Mingce Long, Xiaolei Qu, Heyun Fu, Han Gao, Qilin Li, Pedro J. J. Alvarez, Dongqiang Zhu, Shourong Zheng, and Huiting Liu
- Subjects
Ceramics ,Light ,Industrial Waste ,chemistry.chemical_element ,Nanoparticle ,010501 environmental sciences ,010402 general chemistry ,Photochemistry ,01 natural sciences ,chemistry.chemical_compound ,Pigment ,Tannic acid ,Environmental Chemistry ,Sulfoselenide ,0105 earth and related environmental sciences ,Cadmium ,General Chemistry ,Phosphate ,0104 chemical sciences ,Solubility ,chemistry ,visual_art ,Sunlight ,visual_art.visual_art_medium ,Nanoparticles ,Cadmium pigments ,Visible spectrum - Abstract
Cadmium pigments are widely used in the polymer and ceramic industry. Their potential environmental risk is under debate, being the major barrier for appropriate regulation. We show that 83.0 ± 0.2% of hazardous cadmium ion (Cd2+) was released from the commercial cadmium sulfoselenide pigment (i.e., cadmium red) in aqueous suspension within 24 h under simulated sunlit conditions. This photodissolution process also generated sub-20 nm pigment nanoparticles. Cd2+ release is attributed to the reactions between photogenerated holes and the pigment lattices. The photodissolution process can be activated by both ultraviolet and visible light in the solar spectrum. Irradiation under alkaline conditions or in the presence of phosphate and carbonate species resulted in reduced charge carrier energy or the formation of insoluble and photostable cadmium precipitates on pigment surfaces, mitigating photodissolution. Tannic acid inhibited the photodissolution process by light screening and scavenging photogenerated ho...
- Published
- 2017
45. Bioavailability of Soil-Sorbed Tetracycline to Escherichia coli under Unsaturated Conditions
- Author
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Brian J. Teppen, Zeyou Chen, Dongqiang Zhu, Stephen Boyd, Yanzheng Gao, James M. Tiedje, Hui Li, Wei Zhang, Gang Wang, and Yingjie Zhang
- Subjects
0301 basic medicine ,food.ingredient ,Tetracycline ,030106 microbiology ,Biological Availability ,010501 environmental sciences ,medicine.disease_cause ,complex mixtures ,01 natural sciences ,Soil ,03 medical and health sciences ,food ,Escherichia coli ,medicine ,Soil Pollutants ,Environmental Chemistry ,Agar ,0105 earth and related environmental sciences ,biology ,Chemistry ,General Chemistry ,biology.organism_classification ,Anti-Bacterial Agents ,Bioavailability ,Loam ,Environmental chemistry ,Soil water ,Bioreporter ,Bacteria ,medicine.drug - Abstract
Increasing concentrations of anthropogenic antibiotics in soils are partly responsible for the proliferation of bacterial antibiotic resistance. However, little is known about how soil-sorbed antibiotics exert selective pressure on bacteria in unsaturated soils. This study investigated the bioavailability of tetracycline sorbed on three soils (Webster clay loam, Capac sandy clay loam, and Oshtemo loamy sand) to a fluorescent Escherichia coli bioreporter under unsaturated conditions using agar diffusion assay, microscopic visualization, and model simulation. Tetracycline sorbed on the soils could be desorbed and become bioavailable to the E. coli cells at matric water potentials of -2.95 to -13.75 kPa. Bright fluorescent rings were formed around the tetracycline-loaded soils on the unsaturated agar surfaces, likely due to radial diffusion of tetracycline desorbed from the soils, tetracycline uptake by the E. coli cells, and its inhibition on E. coli growth, which was supported by the model simulation. The bioavailability of soil-sorbed tetracycline was much higher for the Oshtemo soil, probably due to faster diffusion of tetracycline in coarse-textured soils. Decreased bioavailability of soil-sorbed tetracycline at lower soil water potential likely resulted from reduced tetracycline diffusion in soil pore water at smaller matric potential and/or suppressed tetracycline uptake by E. coli at lower osmotic potential. Therefore, soil-sorbed tetracycline could still exert selective pressure on the exposed bacteria, which was influenced by soil physical processes controlled by soil texture and soil water potential.
- Published
- 2017
46. Extracellular Saccharide-Mediated Reduction of Au3+ to Gold Nanoparticles: New Insights for Heavy Metals Biomineralization on Microbial Surfaces
- Author
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Dongqiang Zhu, Fuxing Kang, Xiaolei Qu, and Pedro J. J. Alvarez
- Subjects
Chemistry ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,medicine.disease_cause ,01 natural sciences ,Metal ,Extracellular polymeric substance ,Chemical engineering ,X-ray photoelectron spectroscopy ,Colloidal gold ,visual_art ,visual_art.visual_art_medium ,medicine ,Extracellular ,Environmental Chemistry ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Escherichia coli ,0105 earth and related environmental sciences ,Biomineralization - Abstract
Biomineralization is a critical process controlling the biogeochemical cycling, fate, and potential environmental impacts of heavy metals. Despite the indispensability of extracellular polymeric substances (EPS) to microbial life and their ubiquity in soil and aquatic environments, the role played by EPS in the transformation and biomineralization of heavy metals is not well understood. Here, we used gold ion (Au3+) as a model heavy metal ion to quantitatively assess the role of EPS in biomineralization and discern the responsible functional groups. Integrated spectroscopic analyses showed that Au3+was readily reduced to zerovalent gold nanoparticles (AuNPs, 2–15 nm in size) in aqueous suspension of Escherichia coli or dissolved EPS extracted from microbes. The majority of AuNPs (95.2%) was formed outside Escherichia coli cells, and the removal of EPS attached to cells pronouncedly suppressed Au3+ reduction, reflecting the predominance of the extracellular matrix in Au3+ reduction. XPS, UV–vis, and FTIR a...
- Published
- 2017
47. Enhanced adsorption of aromatic chemicals on boron and nitrogen co-doped single-walled carbon nanotubes
- Author
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Yongsheng Chen, Dongqiang Zhu, Wei Chen, Lilin Wang, and Jingwen Chen
- Subjects
Materials science ,Materials Science (miscellaneous) ,Inorganic chemistry ,Selective chemistry of single-walled nanotubes ,chemistry.chemical_element ,02 engineering and technology ,Electron ,Carbon nanotube ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nitrogen ,law.invention ,Adsorption ,chemistry ,Chemical engineering ,law ,0210 nano-technology ,Boron ,Polarization (electrochemistry) ,Co doped ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
By altering surface electron distribution of carbon nanotubes and creating structural defects, co-doping with B and N promotes polarization of π electrons on carbon nanotube surfaces and thus, generates more abundant π-electron-rich and π-electron-deficit sites that are beneficial for the adsorption of both π-acceptor and π-donor aromatic compounds.
- Published
- 2017
48. Prediction of Apolar Compound Sorption to Aquatic Natural Organic Matter Accounting for Natural Organic Matter Hydrophobicity Using Aqueous Two-Phase Systems
- Author
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Xiaolei Qu, Dongqiang Zhu, Heyun Fu, and Kun Liu
- Subjects
chemistry.chemical_classification ,Aqueous solution ,Water ,Sorption ,General Chemistry ,010501 environmental sciences ,Free-energy relationship ,01 natural sciences ,Organic compound ,Natural organic matter ,Partition coefficient ,Adsorption ,chemistry ,Phase (matter) ,Environmental chemistry ,Environmental Chemistry ,Organic Chemicals ,Polycyclic Aromatic Hydrocarbons ,Hydrophobic and Hydrophilic Interactions ,0105 earth and related environmental sciences - Abstract
The equilibrium partitioning of organic compounds to natural organic matter (NOM) plays a key role in their environmental fate as well as bioavailability. In this study, a prediction model for organic compound sorption to NOM was theoretically derived based on two-phase systems. In this model, the hydrophobicity of NOM was scaled by their partition coefficients in an aqueous two-phase system (KATPS) and that of organics was scaled by their octanol-water partition coefficients (KOW). The model uses only KATPS and KOW as variables. Coefficients in the model were determined using a data set including the organic carbon-water partition coefficient (KOC) of four polycyclic aromatic hydrocarbons (PAHs) sorption to 10 NOM samples collected from surface waters. The resulting model was validated using additional NOM samples and reference NOM, which suggested good prediction power for PAH sorption to aquatic NOM. The model performance was compared with commonly used linear free energy relationship models, and its applicability was discussed. Sorption behavior unexpected by this model is attributed to additional sorption mechanisms other than partitioning. Overall, this approach allows prediction of KOC for apolar organic compound sorption to aquatic NOM simply using their respective partition coefficients in two-phase systems based on a specific model.
- Published
- 2019
49. Spectroscopic and molecular modeling investigation on inhibition effect of nitroaromatic compounds on acetylcholinesterase activity
- Author
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Minli Wang, Xiaolei Qu, Fuxing Kang, Heyun Fu, Yiqun Chen, Zhaobin Zhang, and Dongqiang Zhu
- Subjects
Models, Molecular ,Circular dichroism ,Environmental Engineering ,Molecular model ,Stereochemistry ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Aromatic amino acids ,Environmental Chemistry ,Protein secondary structure ,0105 earth and related environmental sciences ,Spectrum Analysis ,Public Health, Environmental and Occupational Health ,Tryptophan ,General Medicine ,General Chemistry ,Pollution ,Acetylcholinesterase ,Enzyme structure ,020801 environmental engineering ,chemistry ,Proton NMR - Abstract
Nitroaromatic compounds (NACs) are widely distributed in the environment and are considered toxic or carcinogenic. However, little attention has been paid to the binding interactions between NACs and biomacromolecules (e.g., proteins). Here we investigated the effects of three model NACs, nitrobenzene (NB), 1,3-dinitrobenzene (DNB), and 1,3,5-trinitrobenzene (TNB), on the activity of acetylcholinesterase (AChE). The presence of NACs (up to 0.5 mM) effectively suppressed the AChE-catalyzed hydrolysis of acetylthiocholine iodide, with the suppression effect increasing with the nitro-group substitution (TNB > DNB > NB). Consistently, the UV absorption of AChE at 206 nm arising from the skeleton structure decreased by the addition NACs, and the decrease exhibited the same compound sequence, reflecting the perturbing interactions with the skeleton enzyme structure. However, no changes were made on the secondary structure of AChE, as evidenced by the circular dichroism analysis. The fluorescence quenching analysis of AChE demonstrated that NB and DNB interacted with both tryptophan (Trp) and tyrosine (Tyr) residues, whereas TNB interacted only with Trp. The UV absorption and fluorescence quenching analyses both reflected that the interactions with the non-skeleton aromatic amino acids were weak. 1H NMR analysis confirmed the strong π-π coupling interactions between TNB and model Trp. Molecular simulation indicated that the DNB or TNB molecule was sandwiched between Trp84 and Phe330 at the catalytic site via π-π coupling interactions. The findings highlight the importance of specific interactions of NACs with proteins to cause them to malfunction.
- Published
- 2019
50. Sorption fractionation of bacterial extracellular polymeric substances (EPS) on mineral surfaces and associated effects on phenanthrene sorption to EPS-mineral complexes
- Author
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Yiqun Chen, Xinwei Zhou, Dongqiang Zhu, Xiaolei Qu, Heyun Fu, and Minli Wang
- Subjects
Environmental Engineering ,Goethite ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,Fractionation ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,chemistry.chemical_compound ,Extracellular polymeric substance ,Escherichia coli ,Environmental Chemistry ,Humic acid ,Kaolinite ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Minerals ,Extracellular Polymeric Substance Matrix ,Chemistry ,Public Health, Environmental and Occupational Health ,Sorption ,General Medicine ,General Chemistry ,Phenanthrenes ,Phenanthrene ,Pollution ,020801 environmental engineering ,Montmorillonite ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Adsorption - Abstract
Microbial extracellular polymeric substances (EPS) represent an important source of labile component in natural organic matter (NOM) pool. However, the sorption behavior of EPS to mineral surfaces and associated effects on sorption of hydrophobic organic contaminants (HOCs) are not well understood. Here, we systematically investigated the fractionation of EPS extracted from two different microbial sources (Gram-positive B. subtilis and Gram-negative E. coli) during sorption to montmorillonite, kaolinite, and goethite using collective characterization methods (SEM, electrophoretic mobility, FTIR, 1H NMR, UV–vis, fluorescence, and size exclusion chromatography). The peptide-like substances and acidic components with high aromaticity in B. subtilis EPS were more preferentially sorbed than those fractions in E. coli EPS by the three minerals, especially by goethite. Additionally, goethite sorbed more negatively charged and lower molecular weight fractions compared to montmorillonite. The presorption of EPS (1.68–3.79% organic carbon) on the three minerals increased the sorption distribution coefficient (Kd) of phenanthrene (a model apolar HOC) by 2.83–5.29 times, depending on the EPS-mineral complex. All the six examined EPS-mineral complexes exhibited approximately one order of magnitude larger organic carbon (OC)-normalized sorption coefficient (KOC) than the two pristine EPS, indicating that the sorptive interactions were pronouncedly facilitated by the sorbed EPS on mineral surfaces. Thus, the type and surface property of minerals as well as the biological source of EPS are key determinants of sorption fractionation of EPS on minerals and in turn affect sorption affinity of apolar HOCs to EPS-mineral complexes.
- Published
- 2021
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