To explore the environment influence of the sediments in Xiangxi Bay (China Three-Gorge Reservoir), spatial and temporal distribution characteristics of total phosphorus (TP), phosphorus fractions, dissolved total pho...To explore the environment influence of the sediments in Xiangxi Bay (China Three-Gorge Reservoir), spatial and temporal distribution characteristics of total phosphorus (TP), phosphorus fractions, dissolved total phosphorus (DTP) of pore water and overlying water in the sediments were investigated. In surveys, the sampling was undertaken from six sites of Xiangxi Bay on 29 March 2009 and 28 March 2010. TP contents ranged from 1111.29 mg/kg to 1941.29 mg/kg with the mean value of 1533.09 mg/kg in 2009 spring and 1600.48 mg/kg in 2010 spring. Five fractions of sedimentary phosphorus, including loosely sorbed phosphorus (NH4Cl-P), redox-sensitive phosphorus (BD-P), metal oxide bound phosphorus (NaOH-P), calcium bound phosphorus (HCl-P), and residual phosphorus (Res-P), were separately quantified. DTP of pore water and overlying water all have positive correlations with NH4Cl-P and BD-P, which indicated that NH4Cl-P and BD-P were the main fractions that can easily release phosphorus in the sediments of Xiangxi Bay.展开更多
To study the relationship between environmental variables and chlorophyll a of spring algal bloom in Xiangxi Bay of Three Gorges Reservoir, stepwise multiple binomial regression and grey relative analysis methods were...To study the relationship between environmental variables and chlorophyll a of spring algal bloom in Xiangxi Bay of Three Gorges Reservoir, stepwise multiple binomial regression and grey relative analysis methods were adopted. In surveys, 13 stations have been investigated and 143 samples were collected weekly from March 4 to May 13 in 2007. The study shows environmental variables (turbidity, total nitrogen, dissolved oxygen, total phosphates and silicate) are key factors during algal bloom. The grey relative values and their permutation indicated that turbidity was the most important factor and had comprehensive effect on chlorophyll a. The more number of interactive variables is found to be an indication of biochemical activity during spring algal bloom in Xiangxi Bay such as DO×TN, Turb×TP and so on. There was good linear relationship between chlorophyll a and the interaction of DO with TN ( , ).The interac-tion of nutrients (TP×TN, TP×SiO4, TN×SiO4) had significant influence to chlorophyll a and probably determined the inter-specific competition at different nutrient concentrations.展开更多
Piezoelectric catalysis, a new catalytic method, is widely used in the field of environmental sanitation, including waste water treatment and dye degradation. However, in the face of the growing environmental pollutio...Piezoelectric catalysis, a new catalytic method, is widely used in the field of environmental sanitation, including waste water treatment and dye degradation. However, in the face of the growing environmental pollution problem, the efficiency of piezoelectric catalysis is still hampered by the stress variation in the natural environment. Therefore, it is particularly important to improve the catalytic efficiency of piezoelectric materials. We divide piezoelectric materials into two categories: inorganic piezoelectric materials and organic piezoelectric materials. Then the mainstream inorganic piezoelectric materials are divided into four subcategories, namely:(1) MTiO_(3)(M = Ba, Sr),(2) bi-class catalytic materials,(3) MoX_(2)(X = S,Se), and(4) ZnO piezoelectric materials. The mainstream organic piezoelectric materials are divided into PVDF and g-C_(3)N_(4)materials. At the same time, the above materials are summarized to explain the excellent performance of materials from the perspective of structure and piezoelectric principle. In addition,we summarized the modification methods that can be applied to piezoelectric materials:(1) Morphology methods,(2) composites with heterojunctions, and(3) surface modification. Finally, we summarized the prospects of piezoelectric materials in the field of environment and water treatment.展开更多
With increasing concerns on the environment and human health,the degradation of glyphosate through the formation of less toxic intermediates is of great importance.Among the developed methods for the degradation of gl...With increasing concerns on the environment and human health,the degradation of glyphosate through the formation of less toxic intermediates is of great importance.Among the developed methods for the degradation of glyphosate,photodegradation is a clean and efficient strategy.In this work,we report a new photocatalyst by doping F ion on BiVO_(4) that can efficiently degrade glyphosate and reduce the toxic emissions of aminomethylphosphonic acid(AMPA)through the selective(P)−C−Ncleavage in comparison of BiVO_(4) catalyst.The results demonstrate that the best suppression of AMPA formation was achieved by the catalyst of 0.3F@BiVO_(4) at pH=9(AMPA formation below10%).In situ attenuated total reflectance Fourier transforms infrared(ATR-FTIR)spectroscopy indicates that the adsorption sites of glyphosate on BiVO_(4) and 0.3F@BiVO_(4) are altered due to the difference in electrostatic interactions.Such an absorption alteration leads to the preferential cleavage of the C−Nbond on the N−C−P skeleton,thereby inhibiting the formation of toxic AMPA.These results improve our understanding of the photodegradation process of glyphosate catalyzed by BiVO_(4)-based catalysts and pave a safe way for abiotic degradation of glyphosate.展开更多
Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater.This study provides a green,efficient and novel approach to remove cepha...Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater.This study provides a green,efficient and novel approach to remove cephalosporins,particularly cefoperazone sodium(CFP).Bi_(4)O_(5)Br_(2) was chosen for the first time to systematically study its degradation for CFP,including the analysis of material structure,degradation performance,the structure and toxicity of the transformation products,etc.The degradation rate results indicated that Bi_(4)O_(5)Br_(2) had an excellent catalytic activity leading to 78%CFP removal compared with the pure BiOBr(38%)within 120 min of visible light irradiation.In addition,the Bi_(4)O_(5)Br_(2) presents high stability and good organic carbon removal efficiency.The effects of the solution p H(3.12-8.75)on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline conditions.Combined with active species and degradation product identification,the photocatalytic degradation pathways of CFP by Bi_(4)O_(5)Br_(2) was proposed,including hydrolysis,oxidation,reduction and decarboxylation.Most importantly,the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate ofβ-lactam bond cleavage in CFP molecule,quite different from the mostly previous studies.Furthermore,the final products were demonstrated to be less toxic through the toxicity analysis.Overall,this study illustrates the detailed mechanism of CFP degradation by Bi_(4)O_(5)Br_(2) and confirms Bi_(4)O_(5)Br_(2) to be a promising material for the photodegradation of CFP.展开更多
Eichhornia crassipes is a hyperaccumulator of metals and has been widely used to remove metal pollutants from water, but disposal of contaminated plants is problematic.Biochar prepared from plants is commonly used to ...Eichhornia crassipes is a hyperaccumulator of metals and has been widely used to remove metal pollutants from water, but disposal of contaminated plants is problematic.Biochar prepared from plants is commonly used to remediate soils and sequester carbon.Here, the catalytic activity of biochar prepared from plants enriched with iron was investigated as a potentially beneficial use of metal-contaminated plants.In a 30-day hydroponic experiment, E.crassipes was exposed to different concentrations of Fe(Ⅲ)(0, 4, 8, 16, 32 and 64 mg/L), and Fe-biochar(Fe-BC) was prepared by pyrolysis of the plant roots.The biochar was characterized using X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive X-ray spectrometry(EDS), Brunauer–Emmett–Teller(BET) analysis, X-ray photoelectron spectroscopy(XPS) and atomic absorption spectrometry(AAS).The original root morphology was visible and iron was present as γ-Fe2O3 and Fe3O4.The biochar enriched with Fe(Ⅲ) at 8 mg/L(8-Fe-BC) had the smallest specific surface area(SSA, 13.54 m^2/g) and the highest Fe content(27.9 mg/g).Fe-BC catalytic activity was tested in the electrocatalytic reduction of H2O2 using cyclic voltammetry(CV).The largest reduction current(1.82 mA/cm^2) was displayed by 8-Fe-BC, indicating the highest potential catalytic activity.We report here, for the first time, on the catalytic activity of biochar made from iron-enriched plants and demonstrate the potential for reusing metalcontaminated plants to produce a biochar catalyst.展开更多
Three different nanorod-like gallium oxides with mono/poly-crystalline nature(α, β, and α/β-Ga2O3) were prepared by regulating the amount of polyethylene glycol(PEG) 6000 in the range of 0.2–0.8 g proportionally ...Three different nanorod-like gallium oxides with mono/poly-crystalline nature(α, β, and α/β-Ga2O3) were prepared by regulating the amount of polyethylene glycol(PEG) 6000 in the range of 0.2–0.8 g proportionally via a hydrothermal method combined with further calcination. The bandgap of the products, given by UV-Vis diffuse reflectance spectra(UV-Vis DRS), was in the order of α-Ga2O3 > α/β-Ga2O3 > β-Ga2O3. To further investigate the photocatalysis performance of the catalysts, the decomposition of rhodamine B(Rh B) by Ga2O3 under UV light illumination(λ < 387 nm) was presented and complete degradation could be achieved within 30 min, a result that showed the highest efficiency. The photocatalytic oxidation mechanism is further discussed and prominently related to the active species: hydroxyl radical(·OH) and superoxide radical(O·-2), which were confirmed by electron paramagnetic resonance(EPR).展开更多
In this study, bismuth oxyhalide（Bi OXs（X_Cl, Br, I）） semiconductors were prepared by a simple solvothermal method, with ethanol serving as solvent and a series of tetrabutylammonium halide surfactants as halogen ...In this study, bismuth oxyhalide（Bi OXs（X_Cl, Br, I）） semiconductors were prepared by a simple solvothermal method, with ethanol serving as solvent and a series of tetrabutylammonium halide surfactants as halogen sources. Under identical synthetic conditions, Bi OBr was more readily constructed into regular flower-like hierarchical architectures. The photocatalytic properties of the materials were studied by monitoring the degradation of rhodamine B（Rh B）,with visible light absorption, and colorless salicylic acid（SA）. It was found that both Rh B and SA were rapidly degraded on the surface of Bi OBr. Bi OCl was rather active for the degradation of Rh B,but ineffective toward the degradation of SA. However, neither Rh B nor SA could be degraded effectively in the case of Bi OI. Further experiments such as UV–visible spectroscopy and detection of U OH and O2 Uradicals suggest that the electronic structure of the Bi OX photocatalysts is responsible for the difference in their activities.展开更多
Graphite and graphene electrodes were prepared by using pure graphite as precursor. The electrode materials were characterized by a scanning electron microscope（SEM）, X-ray diffraction（XRD） and cyclic voltammetry...Graphite and graphene electrodes were prepared by using pure graphite as precursor. The electrode materials were characterized by a scanning electron microscope（SEM）, X-ray diffraction（XRD） and cyclic voltammetry（CV） measurements. The electro-catalytic activity for degradation of sulfisoxazole（SIZ） was investigated by using prepared graphene or graphite anode. The results showed that the degradation of SIZ was much more rapid on the graphene than that on the graphite electrode. Moreover, the graphene electrode exhibited good stability and recyclability. The analysis on the intermediate products and the measurement of active species during the SIZ degradation demonstrated that indirect oxidation is the dominant mechanism, involving the electro-catalytic generation of OH and O_2^- as the main active oxygen species. This study implies that graphene is a promising potential electrode material for long-term application to electro-catalytic degradation of organic pollutants.展开更多
文摘To explore the environment influence of the sediments in Xiangxi Bay (China Three-Gorge Reservoir), spatial and temporal distribution characteristics of total phosphorus (TP), phosphorus fractions, dissolved total phosphorus (DTP) of pore water and overlying water in the sediments were investigated. In surveys, the sampling was undertaken from six sites of Xiangxi Bay on 29 March 2009 and 28 March 2010. TP contents ranged from 1111.29 mg/kg to 1941.29 mg/kg with the mean value of 1533.09 mg/kg in 2009 spring and 1600.48 mg/kg in 2010 spring. Five fractions of sedimentary phosphorus, including loosely sorbed phosphorus (NH4Cl-P), redox-sensitive phosphorus (BD-P), metal oxide bound phosphorus (NaOH-P), calcium bound phosphorus (HCl-P), and residual phosphorus (Res-P), were separately quantified. DTP of pore water and overlying water all have positive correlations with NH4Cl-P and BD-P, which indicated that NH4Cl-P and BD-P were the main fractions that can easily release phosphorus in the sediments of Xiangxi Bay.
文摘To study the relationship between environmental variables and chlorophyll a of spring algal bloom in Xiangxi Bay of Three Gorges Reservoir, stepwise multiple binomial regression and grey relative analysis methods were adopted. In surveys, 13 stations have been investigated and 143 samples were collected weekly from March 4 to May 13 in 2007. The study shows environmental variables (turbidity, total nitrogen, dissolved oxygen, total phosphates and silicate) are key factors during algal bloom. The grey relative values and their permutation indicated that turbidity was the most important factor and had comprehensive effect on chlorophyll a. The more number of interactive variables is found to be an indication of biochemical activity during spring algal bloom in Xiangxi Bay such as DO×TN, Turb×TP and so on. There was good linear relationship between chlorophyll a and the interaction of DO with TN ( , ).The interac-tion of nutrients (TP×TN, TP×SiO4, TN×SiO4) had significant influence to chlorophyll a and probably determined the inter-specific competition at different nutrient concentrations.
基金Acknowledgments This research was supported by Hubei Provincal Department of Education （No. CXY2009B2008）, Angel Yeast Co.Ltd （SDH200800230）, the Science Foundation of Yichang City （No. A2007103-1）, the Alan G. MacDiarmid Institute of Renewable Energy, Yichang, China and the USDA Western Regional Research Center （WRRC）. The authors thank WRRC Center Director James N. Seiber, Artur, Klamczynski and Charles Lee for the thoughtful discussions and technical insights, and Miss Tina William for the SEM imagines.
基金supported by the National Natural Science Foundation of China (Nos.51872147, 22136003)Hubei Provincial Natural Science Founction of China (No.2022CFA065)the 111 Project(No.D20015)。
文摘Piezoelectric catalysis, a new catalytic method, is widely used in the field of environmental sanitation, including waste water treatment and dye degradation. However, in the face of the growing environmental pollution problem, the efficiency of piezoelectric catalysis is still hampered by the stress variation in the natural environment. Therefore, it is particularly important to improve the catalytic efficiency of piezoelectric materials. We divide piezoelectric materials into two categories: inorganic piezoelectric materials and organic piezoelectric materials. Then the mainstream inorganic piezoelectric materials are divided into four subcategories, namely:(1) MTiO_(3)(M = Ba, Sr),(2) bi-class catalytic materials,(3) MoX_(2)(X = S,Se), and(4) ZnO piezoelectric materials. The mainstream organic piezoelectric materials are divided into PVDF and g-C_(3)N_(4)materials. At the same time, the above materials are summarized to explain the excellent performance of materials from the perspective of structure and piezoelectric principle. In addition,we summarized the modification methods that can be applied to piezoelectric materials:(1) Morphology methods,(2) composites with heterojunctions, and(3) surface modification. Finally, we summarized the prospects of piezoelectric materials in the field of environment and water treatment.
基金supported by the National Natural Science Foundation of China(Nos.21972073,22136003,22176110)the Hubei Province Support Project of Introducing Intelligence(No.2019BJH004)the 111 Project of China(No.D20015).
文摘With increasing concerns on the environment and human health,the degradation of glyphosate through the formation of less toxic intermediates is of great importance.Among the developed methods for the degradation of glyphosate,photodegradation is a clean and efficient strategy.In this work,we report a new photocatalyst by doping F ion on BiVO_(4) that can efficiently degrade glyphosate and reduce the toxic emissions of aminomethylphosphonic acid(AMPA)through the selective(P)−C−Ncleavage in comparison of BiVO_(4) catalyst.The results demonstrate that the best suppression of AMPA formation was achieved by the catalyst of 0.3F@BiVO_(4) at pH=9(AMPA formation below10%).In situ attenuated total reflectance Fourier transforms infrared(ATR-FTIR)spectroscopy indicates that the adsorption sites of glyphosate on BiVO_(4) and 0.3F@BiVO_(4) are altered due to the difference in electrostatic interactions.Such an absorption alteration leads to the preferential cleavage of the C−Nbond on the N−C−P skeleton,thereby inhibiting the formation of toxic AMPA.These results improve our understanding of the photodegradation process of glyphosate catalyzed by BiVO_(4)-based catalysts and pave a safe way for abiotic degradation of glyphosate.
基金the National Natural Science Foundation of China(Nos.21972073,21677086 and 21577077)Hubei Province Introduces Foreign Talents and Intelligence Projects(No.2019BJH004)+2 种基金China Postdoctoral Science Foundation(No.2018M640721)Postdoctoral Science Foundation of Hubei Province(No.G83)Open Fund of Engineering Research Center of Eco-environment in Three Gorges Reservoir Region(No.KF2019-02)。
文摘Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater.This study provides a green,efficient and novel approach to remove cephalosporins,particularly cefoperazone sodium(CFP).Bi_(4)O_(5)Br_(2) was chosen for the first time to systematically study its degradation for CFP,including the analysis of material structure,degradation performance,the structure and toxicity of the transformation products,etc.The degradation rate results indicated that Bi_(4)O_(5)Br_(2) had an excellent catalytic activity leading to 78%CFP removal compared with the pure BiOBr(38%)within 120 min of visible light irradiation.In addition,the Bi_(4)O_(5)Br_(2) presents high stability and good organic carbon removal efficiency.The effects of the solution p H(3.12-8.75)on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline conditions.Combined with active species and degradation product identification,the photocatalytic degradation pathways of CFP by Bi_(4)O_(5)Br_(2) was proposed,including hydrolysis,oxidation,reduction and decarboxylation.Most importantly,the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate ofβ-lactam bond cleavage in CFP molecule,quite different from the mostly previous studies.Furthermore,the final products were demonstrated to be less toxic through the toxicity analysis.Overall,this study illustrates the detailed mechanism of CFP degradation by Bi_(4)O_(5)Br_(2) and confirms Bi_(4)O_(5)Br_(2) to be a promising material for the photodegradation of CFP.
基金supported by supported by the National Natural Science Foundation of China (Nos.21677086 and 21577078)Hubei Innovation Group Project (No.2015CFA021)+1 种基金the Hubei Foreign Science and Technology Cooperation Project (No.2018AHB020)Three Gorges University Master’s Thesis Training Fund (No.2018SSPY143).
文摘Eichhornia crassipes is a hyperaccumulator of metals and has been widely used to remove metal pollutants from water, but disposal of contaminated plants is problematic.Biochar prepared from plants is commonly used to remediate soils and sequester carbon.Here, the catalytic activity of biochar prepared from plants enriched with iron was investigated as a potentially beneficial use of metal-contaminated plants.In a 30-day hydroponic experiment, E.crassipes was exposed to different concentrations of Fe(Ⅲ)(0, 4, 8, 16, 32 and 64 mg/L), and Fe-biochar(Fe-BC) was prepared by pyrolysis of the plant roots.The biochar was characterized using X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive X-ray spectrometry(EDS), Brunauer–Emmett–Teller(BET) analysis, X-ray photoelectron spectroscopy(XPS) and atomic absorption spectrometry(AAS).The original root morphology was visible and iron was present as γ-Fe2O3 and Fe3O4.The biochar enriched with Fe(Ⅲ) at 8 mg/L(8-Fe-BC) had the smallest specific surface area(SSA, 13.54 m^2/g) and the highest Fe content(27.9 mg/g).Fe-BC catalytic activity was tested in the electrocatalytic reduction of H2O2 using cyclic voltammetry(CV).The largest reduction current(1.82 mA/cm^2) was displayed by 8-Fe-BC, indicating the highest potential catalytic activity.We report here, for the first time, on the catalytic activity of biochar made from iron-enriched plants and demonstrate the potential for reusing metalcontaminated plants to produce a biochar catalyst.
基金funded by the National Natural Science Foundation of China(21377067,21177072,and 21207079)the Natural Science Foundation for the Innovation Group of Hubei Province,China(2009CDA020)
文摘Three different nanorod-like gallium oxides with mono/poly-crystalline nature(α, β, and α/β-Ga2O3) were prepared by regulating the amount of polyethylene glycol(PEG) 6000 in the range of 0.2–0.8 g proportionally via a hydrothermal method combined with further calcination. The bandgap of the products, given by UV-Vis diffuse reflectance spectra(UV-Vis DRS), was in the order of α-Ga2O3 > α/β-Ga2O3 > β-Ga2O3. To further investigate the photocatalysis performance of the catalysts, the decomposition of rhodamine B(Rh B) by Ga2O3 under UV light illumination(λ < 387 nm) was presented and complete degradation could be achieved within 30 min, a result that showed the highest efficiency. The photocatalytic oxidation mechanism is further discussed and prominently related to the active species: hydroxyl radical(·OH) and superoxide radical(O·-2), which were confirmed by electron paramagnetic resonance(EPR).
基金supported by the National Natural Science Foundation of China (Nos. 21377067, 21177072, 21207079)Natural Science Foundation for Innovation Group of Hubei Province, China (No. 2009CDA020)open fund (KF2011-07) from the State Key Laboratory of Environmental Chemistry and Ecotoxicology, RCEES, CAS
文摘In this study, bismuth oxyhalide（Bi OXs（X_Cl, Br, I）） semiconductors were prepared by a simple solvothermal method, with ethanol serving as solvent and a series of tetrabutylammonium halide surfactants as halogen sources. Under identical synthetic conditions, Bi OBr was more readily constructed into regular flower-like hierarchical architectures. The photocatalytic properties of the materials were studied by monitoring the degradation of rhodamine B（Rh B）,with visible light absorption, and colorless salicylic acid（SA）. It was found that both Rh B and SA were rapidly degraded on the surface of Bi OBr. Bi OCl was rather active for the degradation of Rh B,but ineffective toward the degradation of SA. However, neither Rh B nor SA could be degraded effectively in the case of Bi OI. Further experiments such as UV–visible spectroscopy and detection of U OH and O2 Uradicals suggest that the electronic structure of the Bi OX photocatalysts is responsible for the difference in their activities.
基金supported by the National Natural Science Foundation of China (Nos. 21377067, 21407092, 21177072)the Master's Degree Thesis Excellent Training Fund of Three Gorges University (No. 2014PY074)
文摘Graphite and graphene electrodes were prepared by using pure graphite as precursor. The electrode materials were characterized by a scanning electron microscope（SEM）, X-ray diffraction（XRD） and cyclic voltammetry（CV） measurements. The electro-catalytic activity for degradation of sulfisoxazole（SIZ） was investigated by using prepared graphene or graphite anode. The results showed that the degradation of SIZ was much more rapid on the graphene than that on the graphite electrode. Moreover, the graphene electrode exhibited good stability and recyclability. The analysis on the intermediate products and the measurement of active species during the SIZ degradation demonstrated that indirect oxidation is the dominant mechanism, involving the electro-catalytic generation of OH and O_2^- as the main active oxygen species. This study implies that graphene is a promising potential electrode material for long-term application to electro-catalytic degradation of organic pollutants.
