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Zhao G.,South China University of Technology | Chen S.,South China University of Technology | Ren Y.,South China University of Technology | Ren Y.,The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | And 4 more authors.
International Biodeterioration and Biodegradation | Year: 2014

Environmentally hazardous and toxic chemicals are commonly generated in actual wastewater that the complex compositions in wastewater treatment system need different types of strains to be degraded. The main objective of this research was to understand the effect of extra substrates, phenolic and N-heterocyclic compounds, on the performance of pure cultural and mixed strains under single and dual substrates conditions. Two bacteria, Lysinibacillus sp. SC03 and Achromobacter sp. DN-06, were acclimated to degrade different concentrations of m-cresol and quinoline. The results indicated that Lysinibacillus sp. SC03 could completely degrade 100mgl-1 m-cresol with no delay time, however, little removal of quinoline was observed; Achromobacter sp. DN-06 could degrade 100mgl-1 quinoline in 32h, but could not remove m-cresol, which means m-cresol and quinoline is the specific substrate. The degradation rate of m-cresol fitted well to the zero-order kinetic equation although the degrading ability of Lysinibacillus sp. SC03 was inhibited when less than 100mgl-1 quinoline was added, and the inhibitive effect was confirmed to be a noncompetitive pattern which could be interpreted by the Michaelis-Menten kinetics equation with corresponding parameters Vmax, Km, K1 and K2 were 13.16mgl-1h-1, 35.84mgl-1, 200.0mgl-1 and 285.7mgl-1, respectively. Moreover, the addition of m-cresol-degrading strain (Lysinibacillus sp. SC03) could accelerate the removal of quinoline because the metabolites of quinoline could be degraded by Lysinibacillus sp. SC03 and the chemical equilibrium moved to more biodegradation of quinoline. Also, this process attributed to less the delay time during the quinoline removal. © 2013 Elsevier Ltd.


Hou Y.,South China University of Technology | Wu P.,South China University of Technology | Wu P.,The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | Wu P.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 3 more authors.
Chemosphere | Year: 2014

The adsorption of Salmon Sperm DNA on three kinds of raw clay (rectorite, montmorillonite and sericite) was investigated as a function of pH, ionic strength and the concentrations of DNA and phosphate ions in solution. The DNA adsorption was reduced in the following order: rectorite montmorillonite sericite. Based on these findings, there is a strong evidence that the mechanisms for DNA adsorption on clay involve electrostatic forces, cation bridging and ligand exchange. Cyclic voltammetry (CV) and UV-vis absorption and fluorescence spectroscopy were used to compare the properties of unbound DNA and the absorbed DNA on rectorite, both in the absence and presence of Cd2+ and Hg2+ inaqueous solutions. The interaction of heavy metals with the unbound DNA was evidenced by the disappearance of reduction peaks in CV, a small bathochromic shift in UV-vis spectroscopy and an incomplete quenching in the emission spectra. Such changes were not observed in the DNA-rectorite hybrids, which is evidence that adsorption on the clay can reduce the extent of the DNA damage caused by heavy metals. Therefore, in these experience the rectorite played an important role in protecting DNA against Cd2+ and Hg2+ induced damage. © 2013 Elsevier Ltd.


Niu X.,South China University of Technology | Niu X.,The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | Niu X.,Eco Remediation of Guangdong Regular Higher Education Institutions | Wei A.,South China University of Technology | And 4 more authors.
Chemosphere | Year: 2013

Ambient levels of phosphine (PH3) in the air, phosphine emission fluxes from paddy fields and rice plants, and the distribution of matrix-bound phosphine (MBP) in paddy soils were investigated throughout the growing stages of rice. The relationships between MBP and environmental factors were analyzed to identify the principal factors determining the distribution of MBP. The phosphine ambient levels ranged from 2.368±0.6060ngm-3 to 24.83±6.529ngm-3 and averaged 14.25±4.547ngm-3. The highest phosphine emission flux was 22.54±3.897ng(m2h)-1, the lowest flux was 7.64±4.83ng(m2h)-1, and the average flux was 14.17±4.977ng(m2h)-1. Rice plants transport a significant portion of the phosphine emitted from the paddy fields. The highest contribution rate of rice plants to the phosphine emission fluxes reached 73.73% and the average contribution was 43.00%. The average MBP content of 111.6ngkg-1fluctuated significantly in different stages of rice growth and initially increased then decreased with increasing depth. The peak MBP content in each growth stage occurred approximately 10cm under the surface of paddy soils. Pearson correlation analyses and stepwise multiple regression analysis showed that soil temperature (Ts), acid phosphatase (ACP) and total phosphorus (TP) were the principal environmental factors, with correlative rankings of Ts>ACP>TP. © 2013 Elsevier Ltd.


Lan Y.,South China University of Technology | Lan Y.,The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters of Ministry of Edu | Luo H.,South China University of Technology | Luo H.,The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters of Ministry of Edu | And 6 more authors.
Microchimica Acta | Year: 2012

A glassy carbon electrode (GCE) was modified by casting gold-palladium (Au-Pd) nanoparticles onto its surface and then used for the determination of As(III) by stripping voltammetry. The structure and electrochemical properties of the nanoparticles were characterized by UV-vis spectroscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry. Anodic stripping voltammetry of the modified electrode was performed in solutions of pH 4. 5 containing various concentrations of arsenite. The modified GCE exhibited good response towards As(III), with a limit of detection of around 0. 25 ppb which is much lower than the current EPA standard of 10 ppb. The electrode is stable and not interfered by Pb(II), Cd(II), Mn(II), and Zn(II). © 2012 Springer-Verlag.


Chen H.,South China University of Technology | Chen H.,The Key Laboratory of Pollution Control | Luo H.,South China University of Technology | Luo H.,The Key Laboratory of Pollution Control | And 9 more authors.
Journal of Hazardous Materials | Year: 2011

The interactions of tetracycline (TC) with nanoscale zerovalent iron (NZVI) modified by polyvinylpyrrolidone (PVP-K30) were investigated using batch experiments as a function of reactant concentration, pH, temperature, and competitive anions. Transmission electron micrographs (TEM), BET surface area and Zeta (ζ)-potential analyses indicated that the mean particle size was 10-40nm with a surface area of 36.90m2/g, and a iso-electric point of PVP-NZVI was 7.2. The results of X-ray diffraction (XRD) and high-resolution X-ray photoelectron spectroscopy (HR-XPS) of modified nanoscale zerovalent iron (PVP-NZVI) revealed that the iron nanoparticles likely have a core of zero-valent iron (Fe0), while a shell is largely made of iron oxides. Degradation of TC was strongly dependent on pH and temperature. The presence of silicate and phosphate strongly inhibited the removal of TC, whereas acetate and sulfate only caused slight inhibition. LC-MS analysis of the treated solution showed that the degradation products from TC resulted from the removal of functional groups from the TC ring. The degradation products were detected both in the treated solution (initial pH of 3.0 and 6.5) and on the surface of PVP-NZVI after 4-h interaction, indicating that PVP-NZVI can adsorb both TC and its degradation products. © 2011.


Ju F.,South China University of Technology | Ju F.,The Key Laboratory of Pollution Control | Hu Y.,South China University of Technology | Hu Y.,The Key Laboratory of Pollution Control | And 3 more authors.
Desalination | Year: 2011

Iron hydroxides prepared from microelectrolysis process were applied to remove EDTA-chelated copper from aqueous solution through adsorption-coprecipitation. To eliminate the occurrence of adverse reactions, Fe(II)-rich effluent of microelectrolysis was pretreated by continuously flushing N 2 for 15min to eliminate dissolved oxygen, then iron hydroxides were generated in less than 30s. The experimental results showed that Fe(II) yields could achieve 530.00-748.00mg/L after 60-min operation of microelectrolysis process at the initial pH of 2.0-2.3. The uptake rate of Cu(II) by iron(II) hydroxides was so rapid under nitrogen-aerated condition that 100% of Cu(II) was removed within only 5min at an initial Fe(II) concentration of 374.0mg/L. However, Cu(II) would desorb from iron hydroxides when iron(II) hydroxides were gradually oxidized into iron(III) hydroxides by oxygen, indicating that iron(II) hydroxide had much higher adsorptive capacity for chelated Cu(II) than iron(III) hydroxide. In addition, iron(II)/(III) hydroxides prepared from microelectrolysis process exhibited a higher removal efficiency of Cu(II) than iron hydroxides prepared from FeSO 4 7H 2O, especially under air-aerated condition. This research provided a novel method for efficient removal of both Cu(II) and EDTA from Cu(II)-chelated wastewater. © 2011 Elsevier B.V.


Li X.,South China University of Technology | Zhu N.,South China University of Technology | Zhu N.,Key Laboratory of Pollution Control | Zhu N.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 8 more authors.
Bioresource Technology | Year: 2013

Animal carcass wastewater (ACW) is a kind of typical high concentration organic wastewater. Up-flow tubular air cathode microbial fuel cells (MFCs) were constructed using 0, 4.0 and 8.0mg/cm2 MnO2 as cathodic catalyst, respectively (MFC-0, MFC-4 and MFC-8) to test the feasibility of bioelectricity production from ACW. After a start-up period of around 55d, when hydraulic retention time (HRT) was set at 3d, MFC-4 showed best bioelectricity performance with the maximum power density of 2.19W/m3 and minimum internal resistance of 30.3Ω, as compared to MFC-0 (1.14W/m3, 62.6Ω) and MFC-8 (1.49W/m3, 34.5Ω). Chemical oxygen demand (COD) and nitrate removal efficiencies of MFC-4 were 50.66% and 79.76%, respectively. Switching HRT from 3d to 6d, COD and nitrate removal efficiencies sped up while the increase rates of ammonia slowed down. The results demonstrated that ACW could be the fuel of MFCs to generate bioelectricity. © 2012 Elsevier Ltd.


Yao H.,South China University of Technology | Ren Y.,South China University of Technology | Ren Y.,Key Laboratory of Pollution Control | Ren Y.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 4 more authors.
Journal of Hazardous Materials | Year: 2011

Phenols and N-heterocyclic compounds are found to co-exist in actual wastewater, especially in petrochemical and coking wastewater. Lysinibacillus cresolivorans, a bacterium capable of phenol-biodegradation was used to study the substrate interactions of m-cresol and pyridine as single and dual substrates. The cell growth and substrate biodegradation kinetics were also investigated with initial m-cresol concentrations varying from 0 to 1200mg/L and pyridine concentrations varying from 0 to 150mg/L. The single substrate kinetics was well described by the Haldane kinetic models. The single-substrate parameter values of m-cresol on cell growth were μ max=0.89h -1, K s= 426.25mg/L, K i=51.26mg/L and μ max=0.0925h -1, K s=60.28mg/L, K i=16.17mg/L for cell growth on pyridine. Inhibitory effects of substrates were observed when cells were grown on the mixed substrates. The interaction parameter I m,p (0.76) was greater than I m,p (0.11), which indicated that m-cresol inhibited the utilization of pyridine much more than pyridine inhibited the biodegradation of m-cresol. The study showed a good potential of L. cresolivorans in degrading mixed substrates of m-cresol and pyridine. © 2010 Elsevier B.V.


Diao C.P.,South China University of Technology | Diao C.P.,Eco Remediation of Guangdong Regular Higher Education Institutions | Wei C.H.,South China University of Technology | Wei C.H.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 2 more authors.
Chromatographia | Year: 2012

An inexpensive, simple and environmentally friendly method based on dispersive liquid liquid microextraction (DLLME) for rapid determination of benzene derivatives in water samples was proposed. A significant improvement of DLLME procedure was achieved. Trace volume ethyl acetate (60 μL) was exploited as dispersion solvent instead of common ones such as methanol and acetone, the volume of which was more than 0.5 mL, and the organic solvent required in DLLME was reduced to a great extent. Only 83-μL organic solvent was consumed in the whole analytic process and the preconcentration procedure was less than 10 min. The advantageous approach coupled with gas chromatograph-flame ionization detector was proposed for the rapid determination of benzene, toluene, ethylbenzene and xylene isomers in water samples. Results showed that the proposed approach was an efficient method for rapid determination of benzene derivatives in aqueous samples. © 2012 Springer-Verlag.


Yang Y.,South China University of Technology | Huang S.,South China University of Technology | Liang W.,South China University of Technology | Liang W.,Eco Remediation of Guangdong Regular Higher Education Institutions | And 3 more authors.
Journal of Hazardous Materials | Year: 2012

The removal of NO X at high temperature by Chelatococcus daeguensis TAD1 in a biotrickling filter was studied. Media components of the recycling liquid were screened using Plackett-Burman design and then were optimized using response surface methodology, which enhanced the efficiency of nitrate removal by TAD1. The optimal medium was used to perform long-term experiments of NO X removal in a biotrickling filter under high concentrations of O 2 and NO in simulated flue gas. Results showed that the biotrickling filter was able to consistently remove 80.2-92.3% NO X when the inlet NO concentration was 600ppm under the conditions of oxygen concentration ranging between 2% and 20% and empty bed residence time (EBRT) being 112.5s. Analyses by polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) indicated that TAD1 was always predominant in the biofilm under a flue gas environment. Overall, the present study demonstrated that utilizing a biotrickling filter inoculated with the aerobic denitrifier TAD1 to remove NO X at high temperature was practically feasible. © 2011 Elsevier B.V.

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