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1. Simultaneous removal of Cr(VI), Cd(II) and Pb(II) from aqueous solution by stabilized iron sulfide nanoparticles: Influencing factors and interactions of heavy metals | |||
ZOU Qingrong,WANG Wanyu,ZHANG Tong,LIU Yuanyuan | |||
Environmental Science and Techology 22 March 2020 | |||
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Abstract:Cadmium (Cd), lead (Pb) and hexavalent chromium (Cr(VI)) often appear simultaneously in the soil and water influenced by metal smelting, chemical manufacturing and electroplating. In this study, synthetic iron sulfide nanoparticles (FeS NPs) stabilized with carboxymethyl cellulose (CMC) were utilized to remove Cr(VI), Cd and Pb from aqueous solution. Batch experiments, Visual MINTEQ model and XPS analysis were used to determine the removal efficiencies, influencing factors and mechanisms. FeS NPs suspension could remove Cr(VI), Cd and Pb simultaneously from aqueous solutions with removal capacities of Cr(VI), Cd and Pb of up to 418, 96, 585 mg per gram of stabilized FeS NPs and with final concentrations of 2.5, 0.1 and 0.1 mg/L at initial concentrations of 50, 10 and 50 mg/L, respectively. The acidic conditions significantly favored the removal of aqueous Cr(VI), while the alkaline conditions favored the removal of Cd and Pb. Oxygen would slightly inhibit the removal of Cr(VI), and there was no significant influence on that of Cd and Pb. A potential mechanism was proposed for the simultaneous removal of Cr(VI), Cd and Pb by using FeS NPs. Interactions of the three heavy metals involves the cationic bridging effect of Cd to promote the adsorption of Cr(VI), the enhanced adsorption effect to Cd by Cr-Fe-hydroxides, and the enhanced precipitation to Pb by chromate and sulfate. Therefore, FeS NPs have a high potential for the simultaneous removal of Cr(VI), Cd and Pb from the contaminated aqueous solutions. | |||
TO cite this article:ZOU Qingrong,WANG Wanyu,ZHANG Tong, et al. Simultaneous removal of Cr(VI), Cd(II) and Pb(II) from aqueous solution by stabilized iron sulfide nanoparticles: Influencing factors and interactions of heavy metals[OL].[22 March 2020] http://en.paper.edu.cn/en_releasepaper/content/4751293 |
2. Bioaccumulation and biomagnification of emerging bisphenol analogues in aquatic organisms from Taihu Lake, China | |||
Wang Qiang,Chen Meng,Zhu Lingyan | |||
Environmental Science and Techology 25 April 2017 | |||
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Abstract:Due to regulations on bisphenol A (BPA) in many countries, a variety of bisphenol analogues are being widely manufactured and applied. However, there is a big knowledge gap on accumulation and biomagnification of these emerging bisphenols in aquatic organisms. The bioaccumulation and magnification of nine bisphenol analogues in aquatic organisms at different trophic levels collected from Taihu Lake, China, were evaluated. The total concentrations of the nine bisphenols in the lake waters were in the range of 49.7-3480 ng/L (average, 389 ng/L). BPA, bisphenol AF (BPAF) and bisphenol S (BPS) were the most predominant analogues in the water. The average natural logarithm bioconcentration factors (log BAFs) of BPAF, bisphenol C (BPC), bisphenol Z (BPZ) and bisphenol E (BPE) were greater than BPA, and there was a significantly positive correlation between log BAFs of the biphenols and their octanol-water partition coefficients (log Kow). The trophic magnification factors of BPAF, BPC and BPZ were 2.52, 2.69 and 1.71, respectively, suggesting that they had the potential to biomagnify in the food web. The results of this study call for further investigations on risk assessment of these emerging pollutants in the environment.????? | |||
TO cite this article:Wang Qiang,Chen Meng,Zhu Lingyan. Bioaccumulation and biomagnification of emerging bisphenol analogues in aquatic organisms from Taihu Lake, China[OL].[25 April 2017] http://en.paper.edu.cn/en_releasepaper/content/4729307 |
3. A high-throughput, computational system to predict if environmental contaminants can bind to human nuclear receptors | |||
WANG Xiaoxiang,ZHANG Xiaowei,XIA Pu,ZHANG Junjiang,WANG Yuting,ZHANG Rui,J.P.Giesy,SHI Wei,YU Hongxia | |||
Environmental Science and Techology 13 October 2016 | |||
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Abstract:Some pollutants can bind to nuclear receptors (NRs) and modulate their activities. Predicting interactions of NRs with chemicals is required by various jurisdictions because these molecular initiating events can result in adverse, apical outcomes, such as survival, growth or reproduction. The goal of this study was to develop a high-throughput, computational method to predict potential agonists of NRs, especially for contaminants in the environment or to which people or wildlife are expected to be exposed, including both persistent and pseudo-persistent chemicals. A 3D-structure database containing 39 human NRs was developed. The database was then combined with AutoDock Vina to develop a System for Predicting Potential Effective Nuclear Receptors (SPEN), based on inverse docking of chemicals. The SPEN was further validated and evaluated by experimental results for a subset of 10 chemicals. Finally, to assess the robustness of SPEN, its ability to predict potentials of 40 chemicals to bind to some of the most studied receptors was evaluated. SPEN is rapid, cost effective and powerful for predicting binding of chemicals to NRs. SPEN was determined to be useful for screening chemicals so that pollutants in the environment can be prioritized for regulators or when considering alternative compounds to replace known or suspected contaminants with poor environmental profiles. | |||
TO cite this article:WANG Xiaoxiang,ZHANG Xiaowei,XIA Pu, et al. A high-throughput, computational system to predict if environmental contaminants can bind to human nuclear receptors[OL].[13 October 2016] http://en.paper.edu.cn/en_releasepaper/content/4706889 |
4. The effect of oxidation on physicochemical properties and aqueous stabilization of multiwalled carbon nanotubes: Comparison of multiple analysis methods | |||
ZHANG Luqing,WANG Minhao,FANG Jing,YANG Kun,LIN Daohui | |||
Environmental Science and Techology 27 June 2016 | |||
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Abstract:Surface oxidation can alter physicochemical properties of multiwalled carbon nanotubes (MWCNTs) and influence their aqueous stabilization. Many techniques have been used to characterize the physicochemical properties and aqueous stabilization of MWCNTs. However, the relationship between the change in physicochemical property and the aqueous stabilization of MWCNTs merits more studies, and the multiple characterization techniques have not been well compared. This study systematically and comparatively investigated the effect of oxidation on the physicochemical properties and aqueous stabilization of MWCNTs using multiple analysis methods. Increased surface area, disclosed tube ends, defects on the sidewalls, disruption of the electronic structure, and removal of metal catalysts and amorphous carbon were observed for the oxidized MWCNTs (o-MWCNTs) using the multipoint Brunauer-Emmett-Teller method, transmission electron microscope observation, Raman spectroscopy, UV-vis spectroscopy, and thermogravimetric analysis. An oxidation-time-dependent increase in oxygen content of the MWCNTs was verified by the methods of elemental analysis, mass difference calculation, and X-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy, XPS, and the Boehm titration were employed to study the functionalities on the MWCNT surfaces. Despite the limitations of these techniques, the results indicated that the dramatic increase in carboxyl groups was mainly responsible for the significant increase in oxygen content after the oxidation. The dissociation of the grafted functional groups increased electronegativity of the o-MWCNTs and facilitated the aqueous stabilization of o-MWCNTs through electrostatic repulsions. The oxidation affected the UV-vis absorbance of MWCNT suspensions. The absorbances at 800 nm of the stabilized MWCNT suspensions had a good correlation with the MWCNT concentrations and could be used to quantify the MWCNT suspensions. The findings of this work are expected to boost the research on carbon nanotubes and their environmental behaviors. | |||
TO cite this article:ZHANG Luqing,WANG Minhao,FANG Jing, et al. The effect of oxidation on physicochemical properties and aqueous stabilization of multiwalled carbon nanotubes: Comparison of multiple analysis methods[J]. |
5. Potential methane production rates and its carbon isotopic composition from ornithogenic tundra soils in coastal Antarctica | |||
Bao Tao,Zhu Renbin,Bai Bo,Xu Hua | |||
Environmental Science and Techology 02 June 2016 | |||
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Abstract:Methane (CH4) is one of important greenhouse gases with chemical activity. The determination of isotopic compositions for CH4 emitted from the soils helps us to understand its production mechanisms. CH4 isotope measurements have been conducted for different types of global terrestrial ecosystems. However, no isotopic data of CH4 have been reported from Antarctic tundra soils. In this paper, the ornithogenic soil profiles were collected from four penguin colonies, and potential CH4 production rates and its δ13C were investigated based upon laboratory incubation experiments. The mean CH4 production rates are highly variable in these soil profiles, ranging from 0.7 to 20.3 μgCH4-C kg-1 h-1. These ornithogenic soils had high potential production rates of CH4 under ambient air incubation or under N2 incubation, indicating the importance of potential CH4 emissions from penguin colonies. Most of soil samples had higher δ13C-CH4 under N2 incubation (-39.28%~-43.53%) than under the ambient air incubation (-42.81%~ -57.19%). Highly anaerobic conditions were conductive to the production of CH4 enriched in 13C, and acetic acid reduction under N2 incubation might be predominant source for soil CH4 production. Overall the δ13C-CH4 showed a significant negative correlation with CH4 production rates in ornithogenic tundra soils under N2 incubation (R2=0.41, p<0.01) or under the ambient air incubation (R2=0.50, p<0.01). Potential CH4 production from ornithogenic soils showed a significant positive correlation with total phosphorus (TP) and NH4+-N contents, pH and soil moisture (Mc), but the δ13C-CH4 showed a significant negative correlation with TP and NH4+-N contents, pH and Mc, indicating that the deposition amount of penguin guano increased potential CH4 production rates from tundra soils, but decreased the δ13C-CH4. The CH4 emissions from the ornithogenic soils affect carbon isotopic compositions of atmospheric CH4 in coastal Antarctica. | |||
TO cite this article:Bao Tao,Zhu Renbin,Bai Bo, et al. Potential methane production rates and its carbon isotopic composition from ornithogenic tundra soils in coastal Antarctica[OL].[ 2 June 2016] http://en.paper.edu.cn/en_releasepaper/content/4694055 |
6. Cytotoxicity of silver nanoapticles to red blood cells: Size-dependent adsorption, uptake and hemolytic activity | |||
CHEN Liqiang,FANG Li | |||
Environmental Science and Techology 04 December 2014 | |||
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Abstract:In this paper, we examined the size-dependent nanotoxicity of AgNPs using three different characteristic sizes of 15 nm (AgNPs15), 50 nm (AgNPs50), and 100 nm (AgNPs100) against fish RBCs. Optical microscopy and TEM observations showed that AgNPs exhibited size effect on their adsorption and uptake by RBCs. The middle sized AgNPs50, compared with small or big ones, showed the highest level of adsorption and uptake by the RBCs, suggesting an optimal size of ~50 nm for passive uptake by RBCs. The toxic effects determined based on the hemolysis, membrane injury, lipid peroxidation and antioxidant enzymes production were fairly size and dose dependent. In particular, the smallest sized AgNPs15 had a greater ability to induce hemolysis and membrane damage than AgNPs50 and AgNPs100. Such cytotoxicity induced by AgNPs should attribute to the direct interaction of nanoparticle with the RBCs, resulting in the production of oxidative stress, membrane injury and subsequently hemolysis. Overall, the results suggest that particle size is a critical factor influencing the interaction between AgNPs and the RBCs. | |||
TO cite this article:CHEN Liqiang,FANG Li. Cytotoxicity of silver nanoapticles to red blood cells: Size-dependent adsorption, uptake and hemolytic activity[OL].[ 4 December 2014] http://en.paper.edu.cn/en_releasepaper/content/4621842 |
7. The role of humic acid in stabilizing fullerene (C60) suspension | |||
ZHANG Luqing,ZHANG Yukun,LIN Xiuchun,YANG Kun,LIN Daohui | |||
Environmental Science and Techology 05 July 2014 | |||
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Abstract:Natural organic matter (NOM) can have a profound effect on the colloidal stability of discharged C60 nanoparticles in the water environment, which will influence the environmental behaviors and risks of C60 and therefore merits more specific studies. This study investigates the effects of humic acid (HA, as a model NOM) on the aqueous stabilization of C60 powders and on the colloidal stability of a previously suspended C60 suspension (aqu/nC60) as affected by variations of pH and ionic strength. Our results reveal that HA could disperse C60 powders in water to some degree, but was unable to stably suspend them. The aqu/nC60 could remain stable at pH > 4 but was destabilized at lower pH ratings. However, the colloidal stability of aqu/nC60 in the presence of HA was insensitive to pH from 3 to 11, owing to the HA adsorption on the nC60 and its increased electrosteric repulsions among the nC60 aggregates. The colloidal stability of aqu/nC60 with and without HA decreased as we increased the valence and concentration of the added cations. The HA was found to mitigate the destabilization effect of Na+ on the colloidal stability of aqu/nC60 by increasing the critical coagulation concentration (CCC) of Na+, while it lowered the CCCs of Ca2+ and La3+ probably owing to the bridging effect of nC60 with the HA aggregates formed through the intermolecular bridging of the HA macromolecules via cation complexation at high concentrations of cations with high valences. | |||
TO cite this article:ZHANG Luqing,ZHANG Yukun,LIN Xiuchun, et al. The role of humic acid in stabilizing fullerene (C60) suspension[J]. |
8. Occurrence of phthalate esters in surface water and sediments from the Pearl River Delta, Southern China | |||
LI Ting,YIN Pinghe,ZHAO Ling | |||
Environmental Science and Techology 26 May 2014 | |||
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Abstract:Rapid developments of the Pearl River Delta (PRD) region in recent decades have resulted in the increasingly serious environmental pollution in and around the region. The 6 priority phthalate esters (PAEs) were investigated in surface water and sediment from seven estuaries within the PRD for assessing the ecological risk to the aquatic environment. The concentration of Σ6PAEs in surface water ranged from 1.26 to 28.1 μg L-1, with a mean concentration of 16.5 μg L-1. It was from 1.56 to 31.2 μg g-1 dw in sediment, with a mean concentration of 9.72 μg g-1 dw. DMP, DBP and DEHP were found in all samples, and they were the predominant PAEs in the region. The distribution of PAEs showed that more serious pollution was found in Humen and the consumption of PAEs was increased in the most recent years in the PRD region. Risk quotient of detected PAEs to the relevant aquatic organisms of fish, daphnids and algae indicated the possible threat for the aquatic environment due to the presence of DBP and DEHP. | |||
TO cite this article:LI Ting,YIN Pinghe,ZHAO Ling. Occurrence of phthalate esters in surface water and sediments from the Pearl River Delta, Southern China[OL].[26 May 2014] http://en.paper.edu.cn/en_releasepaper/content/4598552 |
9. Inhibitory effect of formate on oxidation of Cr(III) under UV irradiation | |||
WANG Zhaohui,XIAO Dongxue,LIU Renlan,LIU Jianshe | |||
Environmental Science and Techology 17 December 2013 | |||
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Abstract:The oxidation processes of Cr(III) to Cr(VI) are not well understood, although the reduction of Cr(VI) has been extensively investigated. Here the effects of the small organic acid, formic acid, on the iron-catalyzed photo-oxidation of Cr(III) were examined. The concentrations of Cr(VI), Fe(II) and H2O2 were monitored to elucidate the reaction mechanisms. In the absence of formate, Cr(III) can be readily oxidized to Cr(VI) by photogenerated oOH from photolysis of ferric hydroxyl complex. The presence of formate diminished the production of Cr(VI) due to its strong radical scavenging capacity for oOH and potential re-reduction of Cr(VI) by its secondary reducing CO2o- radical. However, the yield of CO2o- may be very low because of the much lower quantum yield of oOH in UV/Fe(III) systems. The present study has important implication for understanding the redox chemistry of chromium species in carbon-rich aquatic environment. | |||
TO cite this article:WANG Zhaohui,XIAO Dongxue,LIU Renlan, et al. Inhibitory effect of formate on oxidation of Cr(III) under UV irradiation[OL].[17 December 2013] http://en.paper.edu.cn/en_releasepaper/content/4575806 |
10. The Influence of Adsorbed NOx Stability on NOx Trap Capacity below 200 ℃: Ceria-Zirconia Containing LNT Catalysts | |||
WANG Xinquan,LV Liangfang,ZHANG Qingqing,ZHANG Yuewei,WANG Jun,SHEN Meiqing | |||
Environmental Science and Techology 17 December 2012 | |||
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Abstract:The NOx trap capacity has been investigated by temperature programmed adsorption (TPA) experiments over a variety of Ce/Zr-containing catalysts. A fresh (F) or aged (A) Ce/Zr component, such as Ce0.58Zr0.42O2 (CZ64) or Ce0.80Zr0.20O2 (CZ82), was physical mixed with Pt/Al2O3 (PA) to form a Ce/Zr-Pt/Al2O3 mixture. PA-FCZ64, PA-FCZ82 and PA-ACZ64 show significant improvement in slowing down the premature NO release as temperature ramp from 100 to 150 ℃ However, an obvious NO release occurs on PA-ACZ82 under the same conditions. Using in situ DRIFT spectrometer, we found that nitrites oxidation by lattice oxygen of Ce/Zr was promoted on the fresh samples. It results in low coverage of nitrite with high stability. On the other hand, a large amount of nitrite was formed on PA-ACZ82, which could desorb upon increasing temperature. XPS results show a surface enrichment of Zr on the Ce/Zr samples, and the degree of the enrichment on CZ64 is higher than that on CZ82 for both fresh and aged samples. Segregation of CeO2 from the Ce/Zr phase have occurred on ACZ82, resulting in a lower stability of the nitrite species. | |||
TO cite this article:WANG Xinquan,LV Liangfang,ZHANG Qingqing, et al. The Influence of Adsorbed NOx Stability on NOx Trap Capacity below 200 ℃: Ceria-Zirconia Containing LNT Catalysts[OL].[17 December 2012] http://en.paper.edu.cn/en_releasepaper/content/4500814 |
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