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Wei M.-R.,The Guangxi Key Laboratory of Environmental Engineering | Wei M.-R.,Wuhan University of Technology | Wei M.-R.,China Institute of Technology | Jiang Y.-H.,Wuhan University of Technology | And 3 more authors.
Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology | Year: 2010

Five samples of sediment columns in Nanhu Lake of Wuhan were collected and analyzed, the results showed that the concentration of Organic Matter (OM), Total Nitrogen (TN) and Total Phosphorus (TP) decreased along depth and stabilized gradually under 40 cm, with the maximum appearing in the top sediment; the contaminants content in the sediment column near Xingfucun sewage outlet were the highest. The value of pH, TN, TP and Ammonium-Nitrogen (NH4 +-N) in overlying water and pore water were tested. The results showed that in horizontal distribution the concentrations of TN and NH4 +-N were similar but TP varied distinctively for overlying water, TN, TP and NH4 +-N content in pore water near Xingfucun sewage outlet are the highest; the concentrations of TN and NH4 +-N are higher and TP are less in pore water than that in overlying water, which mean that TN and NH4 +-N in sediment could release into water and TP couldn't.

Yu F.,Guangxi Normal University | Yu F.,The Guangxi Key Laboratory of Environmental Engineering | Liu K.,Guilin University of Electronic Technology | Liu K.,Guangxi Normal University | And 8 more authors.
International Journal of Phytoremediation | Year: 2013

The effects of 60-d cadmium (Cd) exposure on enzymatic and non-enzymatic antioxidative system of Oryza sativa L. seedlings at tillering stage were studied using soil culture experiment. Research findings showed that chlorophyll content of Oryza sativa L. declined with the increase in soil metal concentration. Cd pollution induced the antioxidant stress by inducing O2 -1 and H2O2, which increased in plants; at the same time, MDA as the final product of peroxidation of membrane lipids, accumulated in plant. The antioxidant enzyme system was initiated under the Cd exposure, i.e. almost all the activities of superoxide dismutase (SOD), peroxidase, catalase, glutathione peroxidase, and ascorbate peroxidase were elevated both in leaves and roots. The non-protein thiols including phytochelatins and glutathione to scavenge toxic free radicals caused by Cd stress was also studied. The contents of phytochelatins and glutathione were about 3.12-6.65-fold and 3.27-10.73-fold in leaves, against control; and the corresponding values were about 3.53-9.37-fold and 1.41-5.11-fold in roots, accordingly. © 2013 Copyright Taylor and Francis Group, LLC.

Niu F.,Guangxi University | Yao S.,Guangxi University | Nie S.,Guangxi University | Nie S.,University of New Brunswick | And 4 more authors.
BioResources | Year: 2014

The aims of this study were response surface modeling and optimization of Cr(VI) removal from solution using formaldehyde-modified eucalyptus bark. A high removal rate of Cr(VI) was achieved under the conditions of low adsorbent dosing quantity and high initial concentration of Cr(VI). Analysis of variance showed a high multiple coefficient of determination (R2=0.9875), adjusted determination coefficient (R2 Adj=0.9714), and the good second order regression equation. The initial concentration of Cr(VI) was 40.15 mg/L, adsorbent dosing quantity 3.40 g/L, and initial reaction pH 2.78, and the largest removal rate was 99.998% under the optimum reaction conditions. Langmuir and Freundlich isothermal models described well adsorption of Cr(VI) by the modified stringy bark. Adsorption kinetics studies showed that the adsorption was controlled by multiple factors, dominated by chemical adsorption. The adsorption was found to be spontaneous and endothermic, with ΔG0 < 0, ΔH0 > 0, and ΔS0 > 0. Adsorption of Cr(VI) by formaldehyde-modified stringy bark was partly controlled by REDOX reactions. The adsorbents were characterized by SEM and FTIR.

Yao S.,Guangxi University | Gao C.,Guangxi University | Zhu H.,Guangxi University | Zhang Y.,Guangxi University | And 3 more authors.
BioResources | Year: 2016

In order to further reduce absorbable organic halide (AOX) formation in the bleaching effluent, NH2SO3H and DMSO were added during the elemental chlorine-free (ECF) bleaching (D0EpD1) of bagasse kraft pulp. In the D0 stage, AOX formation decreased by 10% with 0.1% NH2SO3H, and a reduction of 11.2% with 1.0% DMSO, respectively. Ultraviolet (UV) spectra, Fourier transform infrared spectroscopy (FTIR), and gas chromatography-mass spectroscopy (GC-MS) were adopted in characterizing changes of lignin degradation and the main functional groups of bleached pulp. The UV spectrum showed that the quantity of polyphenols decreased after adding the additives. The FTIR spectrum showed that both the content of phenolic-type lignin and the degradation degree of lilac-type lignin decreased after adding NH2SO3H. If was found that DMSO was beneficial in retaining C-O-C and C=O structures in cellulose and hemicellulose, while NH2SO3H decreased the content of β-glycosidic bonds and C-O-C structures in cellulose and hemicellulose. The composition of lignin degradation products in the bleaching effluent was analyzed by GC-MS. The contents of chlorobenzene and chlorophenol decreased notably when additives were added. Compared with DMSO, NH2SO3H exhibited poor inhibition on the formation of some phenols.

Lin Y.,Guangxi Normal University | Lin Y.,The Guangxi Key Laboratory of Environmental Engineering | Zeng L.,CAS East China Sea Fisheries Research Institute | Zhang Q.,Guangxi Normal University | And 3 more authors.
American Journal of Botany | Year: 2011

Premise of the study: Microsatellite markers were developed in an endangered plant, Kmeria septentrionalis, to investigate its population genetic structure, gene flow, and mating systems. Methods and Results: Using the combined biotin capture method, 14 microsatellite primer sets were isolated and characterized. All of these markers showed polymorphism, and the number of alleles per locus ranged from 3 to 15 across 60 individuals from two populations. The observed and expected heterozygosities ranged from 0.2692 to 0.9667 and from 0.3271 to 0.8881, respectively. Conclusions: These markers will facilitate further studies on the genetic diversity and mating systems of K. septentrionalis. © 2011 Botanical Society of America.

Dai Y.,Guangxi University | Dai Y.,Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control | Song X.,Guangxi University | Gao C.,Guangxi University | And 6 more authors.
BioResources | Year: 2016

Xylanase pretreatment was used to improve the chlorine dioxide bleaching of bagasse pulp. The pulp was pretreated with xylanase, which was followed by a chlorine dioxide bleaching stage. The HexA content of the pulp and the AOX content of the bleaching effluent were measured using UV-Vis and GC-MS methods, respectively. The results showed that a good correlation occurred between HexA and kappa number. HexA content of the pulp decreased significantly after the xylanase pretreatment. The AOX content of the bleaching effluent decreased as HexA was removed from the pulp. It was found that AOX could be reduced by up to 29.8%, comparing XD0 with a D0 stage. Fourier transform infrared spectroscopy (FTIR) was employed to determine the breakage of chemical bonds in the pulp. It revealed that some lignin and hemicellulose were removed after xylanase treatment. The GC-MS results showed that some toxic chloride such as 2,4,6-Trichlorophenol could be completely removed after xylanase pretreatment.

Li H.,Chinese Academy of Geological Sciences | Li H.,Guangxi Normal University | Li H.,The Guangxi Key Laboratory of Environmental Engineering | Wang Y.,Guangxi Normal University | And 4 more authors.
2011 International Conference on Electrical and Control Engineering, ICECE 2011 - Proceedings | Year: 2011

Landslides can result in enormous casualties and huge economic losses in mo untainous regions. In order to mitigate landslide hazard effectively, new methodologies are required to develop a better understanding of landslide hazard and to make rational decisions on the allocation of funds for management of landslide risk. In recent years, risk analysis and assessment has become an important tool in addressing uncertainty inherent in landslide hazards. The development of remote sensing techniques and GIS(Geographical Information System) provide multi-data-source and means to monitor landslides, risk assessment and management, and hazard prediction. Therefore, based on remote sensing and GIS, this paper studies the landslide hazards of Yunan in China where landslides occur frequently in regional scale, and presents risk assessment and methods of management. © 2011 IEEE.

Li J.,Guilin University of Technology | Li J.,The Guangxi Key Laboratory of Environmental Engineering | Jia X.,Guilin University of Technology | Yan Y.,Guilin University of Technology | Zhang X.,The Guangxi Key Laboratory of Environmental Engineering
International Journal of Electrochemical Science | Year: 2011

To investigate the mechanism of Cr3+ ion translocation across the cell membranes, the interaction between the Cr3+ ion and the mimic biomembrane of solid supported lipid bilayer (s-BLM) has been investigated quantitatively. The mimic biomembrane was prepared according to the self-assemble of the phosphatidylcholiner(PC)/cholesterol(Ch) membrane on Pt electrode. Using ferricyanide anions species as a redox probe, cyclic voltammetric (CV), Alternating Current (A.C.) impedance spectroscopy (EIS), scanning electrochemical microscopy (SECM) and approach curves were measured. The apparent electron transfer rate constants between the surface of the electrode and redox species was independently calculated from the approach curve, which was measured by SECM, to prove quantitatively the model of the biomimic membrane interacted with Cr3+ in different concentration. The result showed that the apparent electron transfer rate constants increased as the concentration of Cr3+ attached to the surface of the s-BLM increased from 9.00×10-5 cm·s-1 to 1.02×10-2 cm·s-1 while the concentration of Cr3+ from 0 mg·L-1 to 780 mg·L-1 and two obvious platforms were observed at the constants of 9.3×10-4 cms-1 and 7.64×10-3 cms-1 respectively. The mechanism was suggested that Cr3+ ion interacted with the s-BLM and formed the ion-channels owing to the changes of the surface texture of the s-BLM, which resulted chromium ion translocation across mimic biomembrane by Cr3+ interaction with the Pt-BLM. © 2011 by ESG.

Li J.,Guilin University of Technology | Li J.,The Guangxi Key Laboratory of Environmental Engineering | Lin Q.,Guilin University of Technology | Zhang X.,The Guangxi Key Laboratory of Environmental Engineering
Journal of Hazardous Materials | Year: 2010

Leersia hexandra Swartz biogranules were used to adsorb Cr(VI) from aqueous solutions. Batch biosorption experiments showed that the Cr(VI) concentration sharply decreases in the first 15. min. The main functional groups that may be involved in chromium sorption were determined using Fourier transform infrared spectroscopy. The use of X-ray photoelectron spectroscopy confirmed the reduction of Cr(VI) to Cr(III) through L. hexandra Sw. Results indicate that Cr(III) is the dominant species on the surface of the biogranules and that the redox reaction can be accomplished within 40. min. The mechanism of electron transfer during Cr(VI) reduction to Cr(III) was investigated. Protonation of the oxygen-containing groups produces electrostatic-sorption power over Cr(VI). The nitrogen-containing groups serve as the electron-donor groups in the process of reduction-sorption. Moreover, after the complete reduction of Cr(VI), the pH of the suspension significantly increases. © 2010.

Lin Q.,University of Sichuan | Lin Q.,Hezhou University | Wang Q.,University of Sichuan | Duan Y.,University of Sichuan | And 5 more authors.
Separation Science and Technology (Philadelphia) | Year: 2013

A novel adsorbent, chufa corm peels (CCP), is used for removing Cu(II), Cr(III), and Cr(VI) from aqueous solutions. The adsorption ability and characteristics of the CCP are thoroughly investigated. The adsorption capability for three heavy metal ions is in the order of Cu(II) > Cr(III) > Cr(VI). The morphology and elemental distribution on the biomass of CCP were evaluated by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Fourier-transform infrared spectroscopy (FTIR) analysis revealed that oxygen-containing functional groups, especially carboxylic and hydroxyl groups were responsible for chemical coordination between ionizable functional groups and metal ions. The adsorption features were evaluated based on the batch biosorption experiment. The results showed that the adsorption well meets the Freundlich adsorption isotherm models and pseudo-second-order kinetics model. In summary, this work demonstrated that CCP is an attractive, efficient, and low-cost adsorbent biomaterial that can be used for the removal of heavy metals from environmental contaminations. © 2013 Copyright Taylor and Francis Group, LLC.

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