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Your search keyword '"Gu, Xueyuan"' showing total 29 results
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29 results on '"Gu, Xueyuan"'

18. Coupling biological assays with diffusive gradients in thin-films technique to study the biological responses of Eisenia fetida to cadmium in soil

Author

Gu, Xueyuan, Liu, Zhimin, Wang, Xiaorong, Luo, Jun, Zhang, Hao, Davison, William, Ma, Lena Q., Xue, Yingang, Gu, Xueyuan, Liu, Zhimin, Wang, Xiaorong, Luo, Jun, Zhang, Hao, Davison, William, Ma, Lena Q., and Xue, Yingang

Abstract

This work sets out to investigate biological responses of Eisenia fetida to Cd, based on the bioavailable rather than total concentration of Cd, in soils. E. fetida was cultured for 14 d in three selected Chinese soils amended with 0.1–40 mg kg−1 Cd. Potentially bioavailable concentrations of Cd were measured in soil solution, in extractions using CaCl2 and HAc solutions, and using the technique of diffusive gradients in thin-films (DGT). Antioxidant system responses in E. fetida to Cd were measured as biological endpoints. Biological responses were more highly correlated with Cd concentrations evaluated using bioavailable methods than with total concentrations. Cd concentration measured using DGT and CaCl2 extraction provided the narrowest ranges of lowest observed effect concentration (LOEC) values based on biological responses, indicating the potential use of these measurements in management of soil quality and setting soil remediation standards. The LOEC values obtained from 15 field soils contaminated by Cd were similar to those from the three Cd-amended soils and suggested that DGT in particular can be a good tool to predict stress responses of E. fetida to Cd in soils. The study shows the potential of combining biological response and DGT measurements in risk assessment.

Published
2017

19. Speciation of Cd and its relationship with the bioaccumulation of Corbicula fluminea in the sediments of Lake Taihu

Author

Gu Xueyuan, Ren Jinghua, MA Hongrui, Wang Xiaorong, and Geng Jinju

Subjects
biology, Ecology, Chemistry, media_common.quotation_subject, Sediment, Aquatic Science, biology.organism_classification, Pollution, Speciation, Bioaccumulation, Environmental chemistry, Earth and Planetary Sciences (miscellaneous), Sediment contamination, Corbicula fluminea, Water Science and Technology, media_common
Abstract

A simulated experiment exposing Corbicula fluminea in the Cd contaminated sediment of Lake Taihu was conducted in laboratory to study the bioaccumulation of Cd in Corbicula fluminea and the distribution regularity of Cd in water.The speciation of Cd extracted by DGT and BCR and the releasing regularities were determined in sediments of Lake Taihu to obtain the applicability of predicting sediment quality guidelines.When the contaminated concentration increased,the concentration of Cd extracted by DGT and BCR in overlying water and accumulated in Corbicula fluminea increased.The results showed that the content of Cd in Corbicula fluminea was significantly correlated with the results measured by two methods after 14 days and 28 days exposure.It offered theoretical statistics for the prediction of sediment quality guidelines of Cd.

Published
2011

22. Effects of fulvic acid on the bioavailability of rare earth elements and GOT enzyme activity in wheat (Triticum aestivum)

Author

Wang Lian-sheng, Dai Lemei, Cheng Jing, Wang Xiaorong, Gu Zhimang, Chen Yijun, and Gu Xueyuan

Subjects
Environmental Engineering, Health, Toxicology and Mutagenesis, Fulvic acid, Biological Availability, Aspartate transaminase, chemistry.chemical_element, Plant Roots, Botany, Lanthanum, Soil Pollutants, Environmental Chemistry, Benzopyrans, Tissue Distribution, Poaceae, Aspartate Aminotransferases, Triticum, biology, Chemistry, Public Health, Environmental and Occupational Health, General Medicine, General Chemistry, biology.organism_classification, Pollution, Enzyme assay, Bioavailability, Kinetics, Seedling, Environmental chemistry, Bioaccumulation, biology.protein, Metals, Rare Earth
Abstract

Fulvic acid (FA) was extracted and purified from natural soil and the effects of such FA on the bioaccumulation of rare earth elements (REEs, La3+, Gd3+ and Y3+) in wheat seedling were investigated. The results indicated that low concentration of FA (0.4 mg C/l to root,0.7 mg C/l to tops (stem and leaves)) could increase the bioaccumulation values of REEs in wheat, but when the concentration of FA was high (0.4 mg C/l to root,1.5 mg C/l to tops) the bioaccumulation values were decreased. Kinetic experimental results suggested that bioaccumulation values of REEs in roots for 30 days were correlated with the kinetic linear growth equation, and correlation coefficients were higher than 0.861. The kinetic bioaccumulation pattern of REEs in tops was different from that in root. The bioaccumulation values of REEs in wheat root were much higher than in wheat tops. Variations of glutamic oxaloacetic transaminase (GOT) enzyme activities in wheat root and tops were determined. A good correlation existed between the bioaccumulation values of REEs and GOT enzyme activities, and the correlation coefficients were higher than 0.922. GOT is an important parameter influencing the bioavailability of REEs.

Published
2001

23. Effects of humic acid on speciation and bioavailability to wheat of rare earth elements in soil

Author

Gu Zhimang, Gu Xueyuan, Wang Xiaorong, Dai Lemei, and Chen Yijun

Subjects
chemistry.chemical_classification, Chemical Health and Safety, Chemistry, Health, Toxicology and Mutagenesis, media_common.quotation_subject, Rare earth, Toxicology, Bioavailability, Speciation, Environmental chemistry, Botany, Humic acid, Red soil, media_common
Abstract

Humic acid (HA) was extracted from an organic-rich soil in Heilongjian Province of China by 0.5 mol L-1 NaOH. The effects of HA on the distribution of rare earth elements (REEs) in Red Soil, a majo...

Published
2001

24. Multisurface modeling of Ni bioavailability to wheat (Triticum aestivum L.) in various soils.

Author

Zhao, Xiaopeng, Jiang, Yang, Gu, Xueyuan, Gu, Cheng, Taylor, J. Anita, and Evans, Les J.

Subjects
WHEAT, NITROGEN in soils, BIOAVAILABILITY, BIOACCUMULATION in plants, EXTRACTION (Chemistry)
Abstract

Continual efforts have been made to determine a simple and universal method of estimating heavy metal phytoavailability in terrestrial systems. In the present study, a mechanism-based multi-surface model (MSM) was developed to predict the partition of Ni(II) in soil–solution phases and its bioaccumulation in wheat ( Triticum aestivum L. ) in 19 Chinese soils with a wide range of soil properties. MSM successfully predicted the Ni(II) dissolution in 0.01 M CaCl 2 extracting solution ( R 2  = 0.875). The two-site model for clay fraction improved the prediction, particularly for alkaline soils, because of the additional consideration of edge sites. More crucially, the calculated dissolved Ni(II) was highly correlated with the metal accumulation in wheat ( R 2  = 0.820 for roots and 0.817 for shoots). The correlation coefficients for the MSM and various chemical extraction methods have the following order: soil pore water > MSM ≈ diffuse gradient technique (DGT) > soil total Ni > 0.43 M HNO 3  > 0.01 M CaCl 2 . The results suggested that the dissolved Ni(II) calculated using MSM can serve as an effective indicator of the bioavailability of Ni(II) in various soils; hence, MSM can be used as an supplement for metal risk prediction and assessment besides chemical extraction techniques. [ABSTRACT FROM AUTHOR]

Published
2018
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25. Surface complexation modelling of heavy metal adsorption onto natural clay minerals

Author

Gu, Xueyuan and Evans, L.J.

Subjects
sorbent surface, heavy metal adsorption, surface complexation adsorption model, complex mixtures, heavy metal cations, natural clay minerals
Abstract

Adsorption of metals onto soil clay fractions is one of the most important chemical processes for heavy metal cations occurring in soil or sediment environment. Traditional Langmuir or Freundlich isotherm approaches do not indicate the adsorption mechanism. Surface Complexation Models (SCM's) describe the adsorption process by treating the sorbent surface as composed of various functional groups and have been successfully applied to oxide minerals. However, results from the application of SCM's for constant charged phyllosilicate clay minerals have not obtained universal consensus due to their complicated structures and surface charge features. The major objective of this thesis is to establish a simple surface complexation adsorption model for heavy metal cations onto natural clay minerals. Three representative clay minerals (kaolinite, illite and montmorillonite) and five soil clay minerals from Canada and China were investigated. The adsorption of five heavy metal cations, Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II), onto the clay minerals were studied by batch adsorption experiments as a function of pH and ionic strength. Results suggested there were two dominant processes involved in the adsorption of the metals: (1) at lower pH values, the adsorption occurred on permanently charged surface sites through outer-sphere ion-exchange reactions; (2) at higher pH values, the adsorption occurred on variable charged mineral edges through specific inner-sphere surface complexation reactions. Changes in ionic strength showed a dramatic effect on the first process but had little effect on the second process. The Constant Capacitance Model was used to describe the electrostatic properties on the variable charged edge sites. A surface adsorption model combining both ion-exchange reactions with surface complexation reactions at the variable charged edge sites could successfully predict the adsorption behaviour of the five metals in various ionic strengths for both pure clay minerals and extracted soil clay minerals. The model scheme could be applied to all the studied clay minerals; however the model parameters, such as the adsorption constants and site densities, were different for case to case because of the wide range of structures and surface charge properties of natural clay minerals from various sources.

Published
2006

29. Adsorption behavior and mechanism of different arsenic species on mesoporous MnFe2O4 magnetic nanoparticles.

Author

Hu, Qingsong, Liu, Yuling, Gu, Xueyuan, and Zhao, Yaping

Subjects
*ARSENIC poisoning, *MAGNETIC nanoparticles, *MESOPOROUS materials, *ARSENIC in water, *ADSORPTION (Chemistry)
Abstract

Arsenic pollution poses severe threat to human health, therefore dealing with the problem of arsenic contamination in water bodies is extremely important. The adsorption behaviors of different arsenic species, such as arsenate (As(V)), p-arsanilic acid (p-ASA), roxarsone (ROX), dimethylarsenate (DMA) from water using mesoporous bimetal oxide magnetic manganese ferrite nanoparticles (MnFe 2 O 4 ) have been detailedly investigated. The adsorbent was synthesized via a facile co-precipitation approach and recovered conveniently owing to its strong magnetic properties. The obtained MnFe 2 O 4 with large surface area and abundant hydroxyly functional groups exhibited excellent adsorption performance for As(V) and p-ASA, in contrast to ROX and DMA with the maximum adsorption capacities of As(V), p-ASA, ROX and DMA of 68.25 mg g −1 , 59.45 mg g −1 , 51.49 mg g −1 , and 35.77 mg g −1 , respectively. The Langmuir model and the pseudo-second-order kinetic model correlated satisfactorily with the adsorption thermodynamics and kinetics, and thermodynamic parameters depicted the spontaneous endothermic nature for the adsorption of different arsenic species. The adsorption mechanism of different arsenic species onto MnFe 2 O 4 nanoparticles at various pH values could be explained by surface complexation and molecular structural variations. Attenuated Total internal Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) further proved that arsenic species were bonded to the surface of MnFe 2 O 4 through the formation of an inner-sphere complex between the arsenic acid moiety and surface metal centers. The results would help to know the interaction of arsenic species with iron-manganese minerals and the mobility of arsenic species in natural environments. [ABSTRACT FROM AUTHOR]

Published
2017
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