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Ke L.,South China University of Technology | Ke L.,City University of Hong Kong | Ke L.,The Key Laboratory of Pollution Control | Zhang C.,City University of Hong Kong | And 4 more authors.
Marine Pollution Bulletin | Year: 2011

The influence of different environmental stresses, including salinity (5-35‰), tidal cycle (6/6, 12/12 and 24/24h of high/low tidal regimes) and nutrient addition (1-6 times background nitrogen and phosphorus content) on Bruguiera gymnorrhiza and Aegiceras corniculatum grown in sediment contaminated with spent lubricating oil (7.5Lm-2) were investigated. The oil-treated 1-year-old mangrove seedlings subject to low (5‰) and high (35‰) salinity had significantly more reduction in growth, more release of superoxide radical (O2-) and higher activity of superoxide dismutase (SOD) than those subject to moderate salinity (15‰). Extended flooding (24/24h of high/low tidal regime) enhanced O2- release and malondialdehyde (MDA) content in both oil-treated species but had little negative effects on biomass production (P>0.05) except the stem of A. corniculatum (P=0.012). The addition of nutrients had no beneficial or even posed harmful effects on the growth and cellular responses of the oil-treated seedlings. © 2011 Elsevier Ltd.

Song X.F.,Sun Yat Sen University | Song X.F.,South China University of Technology | Song X.F.,The Key Laboratory of Pollution Control | Song X.F.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | And 10 more authors.
Environment International | Year: 2013

This study is the first one investigating the correlation between the concentration of polycyclic aromatic hydrocarbon (PAHs) in blood and semen qualities for residents in the Pearl River Delta (PRD) region in China. Blood samples from 53 infertile volunteers were studied for measures of semen quality and 16 PAHs. Information on the study subjects' living habits (such as smoking, drinking and preference of consumption for food) and general information (age, body-mass-index (BMI) and educational background) were also collected. Statistical results showed that age and BMI were significantly and negatively related to semen motilities. The total concentrations of PAHs (∑16 PAHs) in the blood were 12,010, 7493, 9105 and 8647ng/g for factory workers, office workers, technicians and salespersons, respectively. In addition, ∑16 PAHs in the blood of smokers, drinkers and heavy-taste food consumers were 11,950, 11,266 and 12,141ng/g, which were higher than those observed in nonsmokers (10,457ng/g), nondrinkers (10,920ng/g) and light-taste food consumers (9202ng/g), individually. Furthermore, the Pearson correlation analysis results showed significant positive correlations between BMI and ∑16 PAHs in the blood. Statistically significant correlations were observed between semen motilities and ∑16 PAHs in the blood as well. Logistic regression results showed that for each 1ng/g increase in ∑16 PAHs in blood samples, the log odds of experiencing a pregnancy decrease by 0.039 on average. However, more evidences are needed to clarify the impact of PAHs in the blood to male infertility. © 2013 Elsevier Ltd.

Yao H.,South China University of Technology | Ren Y.,South China University of Technology | Ren Y.,The Key Laboratory of Pollution Control | Ren Y.,Higher Education Institutions | And 4 more authors.
Water SA | Year: 2011

A novel strain of m-cresol-degrading bacterium, named as Lysinibacillus cresolivorans, was isolated from aerobic sludge from a coking wastewater treatment plant. This bacterium is able to utilise m-cresol as its sole source of carbon and energy. The optimal pH for growth is 6.8 ~ 7.3 and the optimal temperature is 35°C. Compared to organic nitrogen sources, inorganic nitrogen sources were easily utilised for the m-cresol biodegradation. The degradation rate of m-cresol at different starting concentrations was analysed with zero-order kinetic characteristics. When the initial concentration of m-cresol was 224.2 mg·ℓ -1, the reaction rate reached a maximum at 46.80 mg·(ℓ·h) -1.The cell growth kinetics was also investigated with initial m-cresol concentrations varying from 0 to 1 200 mg·ℓ -1. The growth kinetics was well described by the Haldane kinetic models. The parameter values of m-cresol on cell growth were μ max = 0.89 h -1, K s = 426.25 mg·ℓ -1, K i = 51.26 mg·ℓ-1. Experiments supplementing growth with glucose indicated that this substrate increased the biomass, and also induced the biodegradation of m-cresol. From the results, it can be concluded that Lysinibacillus cresolivorans is an efficient m-cresoldegrading bacterium and that glucose plays multiple roles in the co-substrate condition.

Wu Y.,South China University of Technology | Wu Y.,The Key Laboratory of Pollution Control | Wu Y.,Guangdong Provincial Key Laboratory of Atmospheric environment and Pollution Control | Luo H.,South China University of Technology | And 9 more authors.
Journal of Colloid and Interface Science | Year: 2014

This work describes the preparation of an effective and low-cost porous graphene oxide/sawdust composite by a freeze-drying method. The composite exhibits a strong ability to adsorb nickel ions. The nickel ions adsorbed on graphene oxide/sawdust composite was reduced by sodium borohydride to generate a catalyst which was used in the degradation of phenol in water. The composite and the catalyst were characterized by XPS, FTIR, XRD and SEM. The adsorption of nickel ions by graphene oxide/sawdust composite was initially very fast and then slowly reached equilibrium in around 30. min. The adsorption of nickel ions by the composite could be well-described by the Freundlich isotherm model and the pseudo-second order kinetic model. The performance of the catalyst in phenol degradation was studied as a function of reaction time, dosage, temperature and initial pH. It was found that the catalyst optimally improved the degradation rate at pH 10 with a dose of 2. g/L in about 30. min. The results show that the degradation of phenol was an endothermic reaction and was a good fit to the Langmuir isotherm model. © 2014 Elsevier Inc.

Wu R.-R.,South China University of Technology | Wu R.-R.,Purdue University | Dang Z.,South China University of Technology | Dang Z.,The Key Laboratory of Pollution Control | And 6 more authors.
Journal of Hazardous Materials | Year: 2011

The promotion of hexadecane biodegradation activity by an n-alkane degrading strain of Burkholderia cepacia (GS3C) with yeast extract amendment was studied using various carbon, nitrogen, vitamin, and amino acid amendments. Cytochrome P450 monooxygenase enzymes play a very important role and are especially required to introduce oxygen in n-alkane degradation. These enzymes from GS3C were located and detected using amino acid amendments. It was shown that biodegradation activity was promoted with amino acids amendments. However, only specific amino acids ( l-phenylalanine, l-glutamic acid, l-proline, l-lysine, l-valine and l-leucine) have biodegradation promoting ability for GS3C. Cell protein concentration and cytochrome P450 activity were promoted significantly with the addition of l-phenylalanine and yeast extract. Furthermore, a significant positive linear relationship between cytochrome P450 activity and biodegradation efficiency of GS3C was observed. The results indicate that amino acid is the primary factor of nutrient amendment in promoting hexadecane biodegradation by influencing cytochrome P450 activity in GS3C. © 2010 Elsevier B.V.

Wu P.,South China University of Technology | Wu P.,The Key Laboratory of Pollution Control | Wu P.,Eco Remediation of Guangdong Regular Higher Education Institutions | Zhang Q.,South China University of Technology | And 13 more authors.
Geoderma | Year: 2011

Montmorillonite could be a kind of potential low cost sorbent for various kinds of heavy metals since it is abundant in nature and only needs little processing. Humic acid modified Ca-montmorillonite was prepared so as to adsorb copper (II) (Cu2+), cadmium (II) (Cd2+) and Chromium (III) (Cr3+) ions from aqueous solutions. The obtained materials were characterized by powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Then, batch experiments were carried out to investigate the possible adsorption mechanisms of the metal ions on humic acid modified Ca-montmorillonite. The results showed that the adsorption capacities of the modified clay for the metal ions were improved significantly as compared to that of the raw clay. The maximum adsorption capacities followed the order of Cr3+>Cu2+>Cd2+ for both materials. Furthermore, the adsorption equilibrium data of Cu2+, Cd2+ and Cr3+ by humic acid modified clay showed that the Langmuir model provided better correlation of the equilibrium data than the Freundlich model, as well as for the adsorption of Cu2+ and Cd2+ by the raw clay. However, Cr3+ adsorption isotherm of the raw clay was better represented by the Langmuir model, indicating that the adsorption mechanisms of the trivalent metal ion on humic acid modified Ca-montmorillonite was quite different from that of the raw Ca-montmorillonite. Finally, the adsorption kinetics was evaluated utilizing the Pseudo-first-order, Pseudo-second-order and Elovich equations, respectively. The results showed that the adsorption kinetic data fit well by the Pseudo-second-order equation for all studied systems, suggesting that the adsorption rate depended on the number of ions on the adsorbent surface. © 2011 Elsevier B.V.

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.

Wu C.,South China University of Technology | Wu C.,The Key Laboratory of Pollution Control | Wu C.,Eco Remediation of Guangdong Regular Higher Education Institutions | Wang L.,South China University of Technology | And 3 more authors.
Journal of Environmental Sciences (China) | Year: 2013

The growth rate and size of floc formation is of great importance in water treatment especially in coagulation process. The floc formation kinetics and the coagulation efficiency of synthetic water were investigated by using an on-line continuous optical photometric dispersion analyze and the analysis of water quality. Experimental conditions such as alum dosage, pH value for coagulation, stirring intensity and initial turbidity were extensively examined. The photometric dispersion analyze results showed that coagulation of kaolin suspensions with two coagulants (alum and polyaluminium chloride) could be taken as a two-phase process: slow and rapid growth periods. Operating conditions with higher coagulant doses, appropriate pH and average shear rate might be particularly advantageous. The rate of overall floc growth was mainly determined by a combination of hydraulic and water quality conditions such as pH and turbidity. The measurement of zeta potential indicates that polyaluminium chloride exhibited higher charge-neutralizing ability than alum and achieved lower turbidities than alum for equivalent Al dosages. Under the same operating conditions, the alum showed a higher grow rate, but with smaller floc size. © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

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.

Ren X.,South China University of Technology | Zhang Z.,South China University of Technology | Luo H.,South China University of Technology | Luo H.,The Key Laboratory of Pollution Control | And 4 more authors.
Applied Clay Science | Year: 2014

Fe polycations and cetyltrimethylammonium bromide (CTMAB) were used to synthesize modified montmorillonite. Arsenic removal by modified montmorillonite was investigated through effects of reaction time, adsorbent dosage, solution pH, as well as the associated adsorption isotherms and kinetics. X-ray diffraction (XRD), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were used to explore the characteristics of the raw and modified montmorillonite. It was found that CTMAB had entered the interlayer of the raw montmorillonite (Mont) while Fe polycations adsorbed on the outer surface and formed small flocculent particles. All adsorption processes reached equilibrium within 20min. Pseudo-second-order kinetics and Langmuir adsorption model fit the experimental well. The adsorption capacity on C-Fe-M and Fe-M were 8.85 and 15.15mgg-1 for As(V), respectively, and 13.89 and 16.13mgg-1 for As(III). The adsorption of As(V)/As(III) on modified montmorillonite was significant in the pH range of 4-10. The removal rate exceeded 99% under the condition of pH range 2-10 for As(V). All results showed that modified montmorillonite has a good affinity towards As(V) and As(III). The sorption mechanisms were mainly surface adsorption and electrostatic adhesion. © 2014.

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