Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System

Guangzhou, China

Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System

Guangzhou, China
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Qiu X.,South China Normal University | Qiu X.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | Fang Z.,South China Normal University | Fang Z.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | And 5 more authors.
Chemical Engineering Journal | Year: 2013

Nanoscale zero-valent iron (nZVI) technology is promising for treating the oxidizing pollutants. Understanding the potential risk of nZVI in solution is important for in situ remediation. In this work, the impacts of nZVI on the chemical properties of solution and microorganism were investigated to assess the risk of environmental exposure of nZVI. The effects of salinity (NaCl), pH and humic acid on the chemical stability of nZVI were studied, the concentrations of released toxic ions within 36. days were examined, and the toxicity of solution was evaluated based on the luminous bacteria-based toxicity test. The results indicated that nZVI was chemically stable as the total chromium concentration was below 0.05. mg/L all along and the maximum concentration of released total iron ion was 0.22. mg/L. The results of the toxicity test showed that the reaction products were non-toxic to microorganism even if they existed in solution for a long-term time. © 2012 Elsevier B.V.


Lin J.,South China Normal University | Zhou Z.,South China Normal University | Wang Q.,South China Normal University | Wang Q.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System
Materials Research Bulletin | Year: 2013

GdNbO4:Eu3+ and LuTaO4:Eu3+ have been successfully prepared with different fluxes (NaCl, KCl, NaCl and KCl) by the molten salt method. X-ray diffraction (XRD) patterns illustrated that well crystallized GdNbO4:Eu3+ and LuTaO 4:Eu3+ in the presence of fluxes were formed under reduced temperature (900 C) in contrast to conventional method (GdNbO 4:Eu3+: around 1200 C; LuTaO4:Eu3+: around 1500 C). Scanning electron microscope (SEM) images revealed that well dispersed particles were achieved (granular or rod-like structures). Meanwhile, the photo-luminescent studies demonstrated that both niobate and tantalate are efficient hosts to sensitize europium red emissions. The results indicated that GdNbO4:Eu3+ using NaCl as the flux gave much enhanced red emission whereas LuTaO4:Eu3+ synthesized with the assistance of mixed salts (NaCl-KCl) achieved the best luminescence. © 2013 Elsevier Ltd. All rights reserved.


Wang J.,South China Normal University | Wang J.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | Fang Z.,South China Normal University | Fang Z.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | And 4 more authors.
Ecotoxicology | Year: 2016

This paper was aimed to study the impact of “ageing” (aged in non-saturated soil for 2 and 4 weeks prior to exposure) nanoscale zero-valent iron (nZVI) on the terrestrial plant. The effects of nZVI on Oryza Sativa germination, seedlings growth, chlorophyll biosynthesis, oxidative stress and the activities of antioxidant enzymes at low (250 mg/kg) and high (1000 mg/kg) concentrations were investigated in this study. The results showed that neither the freshly added nor the “ageing” nZVI to the soil had a significant effect on germination, regardless of concentration. At the low concentration, the freshly added nZVI had no visible toxic effects on the rice seedlings growth, but the rice seedlings exhibited obvious toxic symptoms at the high concentration. At the high concentration, toxicity effects of nZVI were reduced after aging with 2 and 4 weeks in soils compared to fresh nZVI, but the “ageing” nZVI continued to significantly inhibit the rice seedlings growth compared with the control, and the inhibition rates of 2 and 4-week-old nZVI were not significantly different. The mechanism of ageing decreased the phytotoxicity of nZVI was due to nZVI particles incomplete oxidation, and some of which had remained in the soil after 4 weeks aged. © 2016 Springer Science+Business Media New York


Xie Y.,South China Normal University | Xie Y.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | Fang Z.,South China Normal University | Fang Z.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | And 4 more authors.
Science of the Total Environment | Year: 2014

Polybrominated diphenyl ethers (PBDEs) are commonly used as additive flame retardants in all kinds of electronic products. PBDEs are now ubiquitous in the environment, with soil as a major sink, especially in e-waste recycling sites. This study investigated the degradation of decabromodiphenyl ether (BDE209) in a spiked soil using Ni/Fe bimetallic nanoparticles. The results indicated that Ni/Fe bimetallic nanoparticles are able to degrade BDE209 in soil at ambient temperature and the removal efficiency can reach 72% when an initial pH of 5.6 and at a Ni/Fe dosage of 0.03. g/g. A declining trend in degradation was noticed with decreasing Ni loading and increasing of initial BDE209 concentration. The degradation products of BDE209 were analyzed by GC-MS, which showed that the degradation of BDE209 was a process of stepwise debromination from nBr to (n. - 1)Br. And a possible debromination pathway was proposed. At last, the degradation process was analyzed as two-step mechanism, mass transfer and reaction. This current study shows the potential ability of Ni/Fe nanoparticles to be used for removal of PBDEs in contaminated soil. © 2014 Elsevier B.V.


Zhou Z.,South China Normal University | Tan C.,South China Normal University | Zheng Y.,South China Normal University | Wang Q.,South China Normal University | Wang Q.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System
Sensors and Actuators, B: Chemical | Year: 2013

A luminescent terbium complex was covalently modified onto anisotropic gold nanostructures (nanoparticles and nanorods) respectively. Two novel emissive gold nanoprobes were successfully developed for selective and rapid determination of vitamin B1 in water. More significantly, electrochemical sensing performances were investigated based on green emissive gold nanoparticles and nanorods which were fabricated by anchoring gold nano-sensors on the surface of glassy carbon electrodes. Both the fluorescence spectra and cyclic voltammetry curves exhibited selective signal changes in the presence of vitamin B1 in comparison with vitamin B2, B3, B4, B5 and B6. It is considered to be the first example that different dimensional fluorescent nano-probes were selected and applied as dual opto-electrochemical sensors for recognizing the same analyte. © 2013 Elsevier B.V.


Fang X.B.,South China Normal University | Fang X.B.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | Fang Z.Q.,South China Normal University | Fang Z.Q.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | And 7 more authors.
Applied Surface Science | Year: 2014

In this study, Fe3O4 nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe3O4 NPs for engineering applications. The obtained EDA-Fe3O4 NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe 3O4 NPs had a crystalline structure with a particle size range of 20-50 nm and a BET surface area of 28 m2 g-1. Functionalization with EDA was able to improve the adsorption selectivity of Fe3O4 for Cr(VI) in Cr(VI)/Cl-or Cr(VI)/SO 4 2- double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe3O4 NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe3O4 NPs retained a high adsorption capacity after several consecutive adsorption-desorption processes, indicating that EDA-Fe3O4 NPs serve as an excellent regenerable adsorbent for Cr(VI). © 2014 Elsevier B.V.


Lin J.,South China Normal University | Wang Q.,South China Normal University | Wang Q.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | Zheng Y.,South China Normal University | Zhang Y.,South China Normal University
CrystEngComm | Year: 2013

The chemical effects of high intensity ultrasound and microwave irradiation on the preparation of europium(iii) activated silver molybdates were investigated and characteristic red emission was successfully achieved at a very low temperature (70°C) in 40 minutes. X-ray powder diffraction results proved that the crystal phase of silver molybdate was heavily related to the pH value. Scanning electron microscopic images revealed rod-like structures of Ag2Mo3O10·1.8H2O and Ag 2Mo2O7 were obtained in the range of pH values between 2 and 5, while growing particles of Ag2MoO4 were formed at pH values of 7 and 8. Furthermore, it has been found that the encapsulation of europium(iii) in monoclinic crystal structure (Ag 2Mo2O7) resulted in enhanced luminescence intensities compared to other crystal phases. © 2013 The Royal Society of Chemistry.


Lin J.,South China Normal University | Huo J.,South China Normal University | Cai Y.,South China Normal University | Wang Q.,South China Normal University | Wang Q.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System
Journal of Luminescence | Year: 2013

In this paper, phosphors of LuF3:Eu3+/Tb3+ have been successfully synthesized with small chelator ethylenediaminetetra acetic acid (EDTA) or amphiphilic polymer (polyethylene glycol, PEG-1000) as templates via a hydrothermal method. X-ray powder diffraction (XRD), scanning electronic microscope (SEM), and photo-luminescent spectra techniques (PL) were used to characterize the as-prepared samples. XRD patterns showed that well crystallized lanthanide fluorides with hexagonal phase were achieved. SEM images revealed that different regular microstructures were achieved. The photo-luminescent properties of LuF3:Eu3+ demonstrated that there are significant energy transfers from fluorides to Eu3+. The results presented that EDTA as the template will lead to the highest emission intensities. © 2013 Elsevier B.V.


Zhou Z.,South China Normal University | Wang Q.,South China Normal University | Wang Q.,Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System | Tan C.,South China Normal University
Soft Materials | Year: 2014

A novel design strategy has been applied to fabricate thermo-sensitive silica based lanthanide luminescent hydrogels (poly(N-isopropylacrylamide)), which possesses intense luminescence and exhibits host-guest interactions with anions. In detail, 2-(2-furyl)-4,5-imidazoledicarboxylic acid (a) was used as sensitizing ligand, which could not only transfer its energy to europium ion but also to terbium ion effectively. We observed that only HSO4 - can give rise to fluorescence quenching to these target materials compared with CH3COO-, F-, Cl-, Br-, and I-. We regarded that it was mainly due to the anion's acidity which resulted the turned-off process. More importantly, the emission intensities of the two hydrogels significantly enhanced at lower critical solution temperature (33°C). Copyright © Taylor & Francis Group, LLC.

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