Chinese Institute of Urban Environment

Xiamen, China

Chinese Institute of Urban Environment

Xiamen, China
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Zhang M.,Chinese Institute of Urban Environment | Zhang K.,Chinese Institute of Urban Environment | De Gusseme B.,Ghent University | Verstraete W.,Ghent University
Water Research | Year: 2012

Biofouling is a major problem for the application of membrane technology in water and wastewater treatment. One of the practical strategies to decrease biofouling is the use of advanced anti-biofouling membrane material. In this study, different amounts of biogenic silver nanoparticles (bio-Ag 0) were embedded in polyethersulfone (PES) membranes, using the phase-inversion method. The effects of the bio-Ag 0 content on the structure of the membrane and its filtration performance were systematically investigated. The results demonstrated that silver-containing nanostructures were uniformly distributed on membrane surface. Bio-Ag 0 incorporation slightly increased the hydrophilicity of the PES membrane and increased the permeate flux. The anti-bacterial and anti-biofouling properties of the bio-Ag 0/PES nanocomposites membrane were tested with pure cultures (Escherichia coli and Pseudomonas aeruginosa) and a mixed culture (an activated sludge bioreactor), respectively. The bio-Ag 0/PES composite membranes, even with the lowest content of biogenic silver (140mgbio-Ag 0m -2), not only exhibited excellent anti-bacterial activity, but also prevented bacterial attachment to the membrane surface and decreased the biofilm formation during a 9 weeks test. © 2012 Elsevier Ltd.

Huang J.,Chinese Institute of Urban Environment | Arthanareeswaran G.,National Institute of Technology Tiruchirappalli | Zhang K.,Chinese Institute of Urban Environment
Desalination | Year: 2012

Polyethersulfone (PES) based ultrafiltration membranes were fabricated via phase inversion by adding silver-loaded sodium zirconium phosphate nanoparticles (nanoAgZ) in PES casting solutions. The effect of nanoAgZ concentration on the membrane performance, i.e., morphology, hydrophilicity, thermal stability, permeation and antifouling properties was investigated. The results of thermal gravitational analysis (TGA) showed that the thermal stability of the hybrid membrane had been improved by the addition of nanoAgZ particles. Contact angle results indicated that the hydrophilicity of the modified membranes was enhanced. The contact angle of the membrane decreased from 71.5° to 52.6° with the increase of the nanoparticle content in the casting solution. Permeation experiment results showed that the modified PES membranes demonstrate better separation performance over the pure PES membrane. The pure water flux of PES membrane increased from 82.1L/m 2h to 100.6L/m 2h with the addition of the nanoparticles. Most importantly, the incorporation of the nanoAgZ particles enhanced the BSA fouling resistance and also the anti-biofouling performance of the membrane. © 2011 Elsevier B.V.

Zhao F.-J.,Nanjing Agricultural University | Zhao F.-J.,Rothamsted Research | Moore K.L.,University of Oxford | Lombi E.,University of South Australia | And 2 more authors.
Trends in Plant Science | Year: 2014

To maintain cellular homeostasis, concentrations, chemical speciation, and localization of mineral nutrients and toxic trace elements need to be regulated. Imaging the cellular and subcellular localization of elements and measuring their in situ chemical speciation are challenging tasks that can be undertaken using synchrotron-based techniques, such as X-ray fluorescence and X-ray absorption spectrometry, and mass spectrometry-based techniques, such as secondary ion mass spectrometry and laser-ablation inductively coupled plasma mass spectrometry. We review the advantages and limitations of these techniques, and discuss examples of their applications, which have revealed highly heterogeneous distribution patterns of elements in different cell types, often varying in chemical speciation. Combining these techniques with molecular genetic approaches can unravel functions of genes involved in element homeostasis. © 2013 Elsevier Ltd.

Shen J.-S.,Chinese Institute of Urban Environment | Xu B.,Chinese Institute of Urban Environment
Chemical Communications | Year: 2011

We found that Ag(i) could serve as a "bridging agent" for triggering sodium carboxymethylcellulose (NaCMC) solution to form a hydrogel which enabled Ag nanocrystals to be in situ produced and encapsulated into the stable gel matrix by means of photoreduction; the conceptual system could act as a novel signaling platform for thiol-containing amino acids or small peptides, operating in a "self-assembly and disassembly" model. © 2011 The Royal Society of Chemistry.

Xue P.-Y.,Chinese Institute of Urban Environment | Yan C.-Z.,Chinese Institute of Urban Environment
Chemosphere | Year: 2011

Worldwide contamination of arsenic in aquatic systems requires the development of a cost-effective, in situ phytoremediation technology. Hydrilla verticillata (L.f.) Royle, a submerged macrophyte widely distributed throughout the world, has the potential to effectively remove heavy metals from water. In order to understand the potential of H. verticillata for As phytofiltration and its impacts on As cycling in the water system, we investigated As accumulation, speciation and translocation in H. verticillata plants. Plant shoots showed a significant accumulation of As, with a maximum of >700μgg-1 dry weight (DW) after exposure to 20μM arsenate [As(V)] or arsenite [As(III)] for 4d, with no significant differences between the As(V) and As(III) treatments (P>0.05). In addition, results of an in planta transport experiment showed that, after exposure of root and shoot to 2μM As(V) and As(III) for 4d, the bioconcentration factor (BCF) in roots for As(V) was almost twofold than that of As(III). Higher As BCFs in roots compared to shoots was also observed. Arsenic accumulated primarily in the cell walls of root cells (>73% of the total As in roots) and in the soluble parts of leaves (>60% of the total As in leaves). Regardless of the form of As supplied [As(III) or As(V)], As(V) was the dominant form in roots and As(III) was the dominant form in leaves. Further, basipetal translocation of As in this plant (≥17%) was markedly higher than acropetal translocation (≤3%). Because of accumulation of As in the shoot and immobilization of As below ground in roots, H. verticillata is a potential As phytofiltrator for bioremediation. © 2011 Elsevier Ltd.

Huang J.,Chinese Institute of Urban Environment | Zhang K.,Chinese Institute of Urban Environment
Desalination | Year: 2011

The aromatic poly (m-phenylene isophthalamide) (PMIA) nanofiltration (NF) membrane with polyvinyl pyrrolidone (PVP) and LiCl as additives was fabricated by phase inversion. The effects of additive content in the casting solution, solvent evaporation temperature and evaporation time during membrane fabrication on the performance of the PMIA NF membrane were investigated. The rejection of the PMIA NF membrane for dyes Eriochrome black T, Eriochrome blue black B and Alizarine red were all over 98%, with a flux about 80L/m2h, while the rejection for NaCl was only about 5.5% when tested at 0.4MPa. The PMIA NF membrane was applied in the desalination and purification process of Eriochrome black T and NaCl mixed solution. The flux increased largely with the increase of the operation pressure and the temperature, while the rejection for dye remained over 99%. The flux decreased with the increase of the concentration of dye and salt in the feed solution while the rejection for dye and salt remained relative stable. The desalination and purification experiment exhibits that the rejection for the dye remained over 99% throughout the whole experiment which indicated that the PMIA-NF membranes could be successfully applied in the dye purification and desalination process. © 2011 Elsevier B.V.

Zhu Y.-G.,Chinese Institute of Urban Environment | Zhu Y.-G.,CAS Research Center for Eco Environmental Sciences | Yoshinaga M.,Florida International University | Zhao F.-J.,Nanjing Agricultural University | And 2 more authors.
Annual Review of Earth and Planetary Sciences | Year: 2014

Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice. © 2014 by Annual Reviews. All rights reserved.

Shen H.,Chinese Institute of Urban Environment
Environmental health : a global access science source | Year: 2014

Exposomics is the cutting-edge concept of screening the environmental risk factors for disease. In the novel "top-down" approach, we estimate the molecular exposome by measuring all body fluid analytes in a case-controlled study. However, to detect diverse pollutants, a sufficient sample size and multiple analytical methods are required. This may lead to dramatically increased costs and research workload. To help reduce complexity, we suggest a sample pooling strategy along with a scheme for combining both general unknown or multi-targeted screening with targeted analysis. The sample pooling method was tested using computer simulations. By comprehensively analysis of pooled samples, it is possible to identify environmental risk factors. Factors are initially screened in the pooled case and control population samples, then in the randomized grouped and pooled case and control subpopulation samples. In the sample grouping, five or more pools were suggested for groups having 30 individuals per pool. This study suggests that sample pooling is a useful strategy for exposomics research, which provides a hypothesis-free method for pollutant risk screening.

Huang Q.,Chinese Institute of Urban Environment
Environmental science and pollution research international | Year: 2011

The prevalence of bisphenol A (BPA) in the environment has attracted increasing attention because of the toxicity of this manmade pollutant. However, the toxicity related to cardiac development remains largely unknown. In the present paper, we investigated the cardiac toxicity of BPA using marine medaka (Oryzias melastigma) embryos. At 2 days postfertilization (dpf), the embryos were continuously exposed to a low concentration of BPA (200 μg/L) for the whole embryonic stage. Heart rate and sinus venosus (SV)-bulbus arteriosus (BA) distance were measured under microscopy. The mRNA expression levels of genes were quantified by SYBR real-time RT-PCR, and hematoxylin and eosin (H&E) staining was used to examine the histology of fish larvae hearts. Neither the heart rate nor the SV-BA distance of the embryos was affected by BPA exposure. However, the mRNA expression levels of Na(+)-K(+)-ATPase, BMP4, COX-1, FGF8, GATA4, and NKX2.5 were all downregulated at the critical developmental stages (6 and 10 dpf). Interestingly, the mRNA expression levels of COX-2 and LERP were significantly upregulated at 10 dpf. The mRNA expressions of inflammation-related genes (TNFα, IL1β, SOD, and CCL11) were all significantly upregulated after exposure. Moreover, we found that both the body length and the body width decreased in the larvae after embryonic exposure to BPA. The distributed foci of inflammation were observed in the juveniles after 2 weeks' depuration. Exposure to BPA at embryonic stages could alter the expression of heart development-related genes and inflammation-related genes of O. melastigma. The larvae hatched from exposed embryos showed the foci of inflammation in the heart ventricles and the decrease of the body length and width.

Ye J.,Chinese Institute of Urban Environment | Rensing C.,University of Arizona | Rosen B.P.,Florida International University | Zhu Y.-G.,Chinese Institute of Urban Environment | Zhu Y.-G.,CAS Research Center for Eco Environmental Sciences
Trends in Plant Science | Year: 2012

Arsenic (As) is a ubiquitous element that is widespread in the environment and causes numerous health problems. Biomethylation of As has implications for its mobility and toxicity. Photosynthetic organisms may play a significant role in As geochemical cycling by methylating it to different As species, but little is known about the mechanisms of methylation. Methylated As species have been found in many photosynthetic organisms, and several arsenite S-adenosylmethionine (SAM) methyltransferases have been characterized in cyanobacteria and algae. However, higher plants may not have the ability to methylate As. Instead, methylated arsenicals in plants probably originate from microorganisms in soils and the rhizosphere. Here, we propose possible approaches for developing 'smart' photosynthetic organisms with an enhanced and sensitive biomethylation capacity for bioremediation and safer food. © 2011 Elsevier Ltd.

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