Co-reporter:Xiuzhen Wei;Jialiang Hong;Shuangshuang Zhu
Journal of Materials Science 2017 Volume 52( Issue 19) pp:11701-11714
Publication Date(Web):05 July 2017
DOI:10.1007/s10853-017-1225-0
Polyethyleneimine (PEI) of various molecular weights and trimesoyl chloride (TMC) were utilized to prepare composite nanofiltration (NF) membranes via interfacial polymerization. The changes in the surface structure and chemical composition of the prepared membranes were evaluated using SEM, ATR-FTIR, XPS and surface potential measurements. The pure-water flux and rejection rates of the inorganic salts (MgCl2, MgSO4, Na2SO4 and NaCl) through the resultant NF membranes were also investigated. The results showed that the performance of the composite NF membranes was significantly affected by the molecular weight of the PEI. Notably, the permeate flux and rejection rate of the NF membranes increased with the PEI molecular weight. In addition, when the NF membranes were used to treat actual wastewater from the electroplating industry, the NF membranes presented high-efficiency separation properties for heavy metal ions. The rejection rates of the NF membranes at 0.4 MPa for chromium, nickel, zinc and copper ions reached 92.6, 89.6, 89.2 and 86.3%, respectively.
Co-reporter:Qinghua Zhou, Baichen Liu, Yimei Chen, Xiaoqian Han, Xiuzhen Wei, Ying Zhu, Xing Zhou, Jinyuan Chen
Chemosphere 2017 Volume 182(Volume 182) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.chemosphere.2017.04.133
•The finer submicron PMs, the higher accumulation efficiency of particulate PAHs.•The finer submicron PMs, the higher carcinogenicity of particulate PAHs.•∼80% of carcinogenicity and cytotoxicity of PM1 were associated with PM0.4.•Intracellular oxidative stress was significantly correlated with particulate PAHs.The submicron atmospheric particulate matters (PMs), consisting of 7 size-resolved fractions, were collected by two Dekati low pressure impactors from December 2015 to January 2016 in Hangzhou, China. The chemical analysis revealed the higher accumulation efficiency of polycyclic aromatic hydrocarbons (PAHs) in the finer submicron PMs, and 77.0% of particulate PAHs in PM1 were associated with PM0.4. Moreover, the BaP equivalent concentrations (BaPeq) were evaluated for size-fractionated submicron PMs, indicating that 77.2% of carcinogenicity of particulate PAHs in PM1 were associated with PM0.4. In the cytotoxic tests, a significant size-dependent decrease of glutathione (GSH) level was observed in the PMs-exposed human pulmonary epithelial cells (A549), demonstrating the greater intracellular oxidative stress induced by the finer submicron PMs. The results also suggested that 82.4% of PM1-induced oxidative stress were associated with PM0.4, and the intracellular oxidative stress was significantly correlated with the particulate PAHs. Therefore, besides PM10, PM2.5 and PM1, special attentions should be given to PM0.4 as well.Download high-res image (213KB)Download full-size image
Co-reporter:Xiuzhen Wei, Songxue Wang, Yingying Shi, Hai Xiang, and Jinyuan Chen
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 36) pp:14036-14045
Publication Date(Web):August 21, 2014
DOI:10.1021/ie5017688
A positively charged, composite, hollow-fiber nanofiltration (NF) membrane was fabricated by interfacial polymerization using polyethylenimine and trimesoyl chloride as reactive monomers. Rejection rates of different salts and dyes were measured by the NF membranes at various pH values. The effects of dye and salt concentrations on the membrane performance for dye purification were investigated. The dye and salt rejection rates would gradually decrease with an increase in the dye and salt concentrations. Then the influence of the volume concentration factor on dye purification during constant volume batch diafiltration process was studied. The results indicated that the higher of the concentration factor was, the better the concentration effect would be, and the less time would be needed.
Co-reporter:Xiuzhen Wei, Huijuan Wang, Guangfeng Zhu, Jinyuan Chen, Liping Zhu
Ceramics International 2013 Volume 39(Issue 4) pp:4009-4016
Publication Date(Web):May 2013
DOI:10.1016/j.ceramint.2012.10.251
Abstract
A series of iron-doped anatase TiO2 nanotubes (Fe/TiO2 NTs) catalysts with iron concentrations ranging from 0.88 to 7.00 wt% were prepared by an ultrasonic-assisted sol-hydrothermal process. The structures and the properties of the fabricated Fe/TiO2 NTs were characterized in detail and photocatalytic activity was examined using a reactive brilliant red X-3B aqueous solution as pollutant under visible light. The lengths of the NTs were determined to range from 20 nm to 100 nm. The incorporation of the iron ions (Fe3+) into the TiO2 nanotubes shifted the photon absorbing zone from the ultraviolet (UV) to the visible wavelengths, reducing the band gap energy from 3.2 to 2.75 eV. The photocatalytic activity of the Fe/TiO2 NTs was 2–4 times higher than the values measured for the pure TiO2 nanotubes.
Co-reporter:Xiuzhen Wei, Xin Kong, Songxue Wang, Hai Xiang, Jiade Wang, and Jinyuan Chen
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 49) pp:17583
Publication Date(Web):November 20, 2013
DOI:10.1021/ie402387u
In this study, thin-film composite nanofiltration (NF) hollow-fiber membranes were used to remove heavy metals from actual electroplating wastewater. The effects of the operating pressure, feed temperature, and feed pH on the membrane performance for the treatment of electroplating wastewater were investigated. The rejection rates for chromium, copper, and nickel ions reached 95.76%, 95.33%, and 94.99%, respectively, at 0.4 MPa. With a rise in the feed temperature, the permeate flux increased while the rejection rates of heavy metals did not significantly change. It was evident that the feed pH greatly affected the permeate flux and heavy-metal rejection as well. In addition, all of the rejection rates of heavy metals by the membrane were over 94.8% throughout the electroplating wastewater concentration process. Also, the NF hollow-fiber membrane showed good stability in electroplating wastewater with a pH value of 2.31.
Co-reporter:Xiuzhen Wei, Xin Kong, Jia Yang, Guoliang Zhang, Jinyuan Chen, Jiade Wang
Journal of Membrane Science 2013 440() pp: 67-76
Publication Date(Web):
DOI:10.1016/j.memsci.2013.03.034
Co-reporter:Jinyuan Chen;Yongxing Qian;Xiuzhen Wei
Journal of Materials Science 2010 Volume 45( Issue 22) pp:6018-6024
Publication Date(Web):2010 November
DOI:10.1007/s10853-010-4685-z
Novel magnetic-nanometer titanium dioxide/ferriferous oxide (TiO2/Fe3O4) composite photocatalyst was prepared using acid–sol and homogenous precipitation methods. The photocatalyst particle was made of a Fe3O4 core covered with nanocrystal anatase TiO2, without a high-temperature heat-treatment step. The catalyst has been characterized by X-ray diffraction, transmission electron microscopy, differential thermal analysis measurements, and ultraviolet spectrum. The results suggested that titania was mainly presented as anatase and Fe3O4 did not appear on the surface of the composite particles when the molar ratio of TiO2/Fe3O4 increased to 20:1 in the acid–sol method, but 5:1 in the homogeneous precipitin method. The size of the crystal was ranged from 2.4 to 3.6 nm prepared by both methods. In the catalytic test, the composite particles, which were prepared by acid–sol, had higher catalytic activity than that prepared by homogenous precipitation method due to the size difference of the composite particles.
Co-reporter:Jinyuan Chen;Xia Dong;Jing Zhao;Guping Tang
Journal of Applied Toxicology 2009 Volume 29( Issue 4) pp:330-337
Publication Date(Web):
DOI:10.1002/jat.1414
Abstract
Because of its excellent optical performance and electrical properties, TiO2 has a wide range of applications in many fields. It is often considered to be physiologically inert to humans. However, some recent studies have reported that nano-sized TiO2 may generate potential harm to the environment and humans. In this paper the in vivo acute toxicity of nano-sized TiO2 particles to adult mice was investigated. Mice were injected with different dosages of nano-sized TiO2 (0, 324, 648, 972, 1296, 1944 or 2592 mg kg–1). The effects of particles on serum biochemical levels were evaluated at various time points (24 h, 48 h, 7 days and 14 days). Tissues (spleen, heart, lung, kidney and liver) were collected for titanium content analysis and histopathological examination. Treated mice showed signs of acute toxicity such as passive behavior, loss of appetite, tremor and lethargy. Slightly elevated levels of the enzymes alanine aminotransferase and aspartate aminotransferase were found from the biochemical tests of serum whereas blood urea nitrogen was not significantly affected (P <0.05). The accumulation of TiO2 was highest in spleen (P <0.05). TiO2 was also deposited in liver, kidney and lung. Histopathological examinations showed that some TiO2 particles had entered the spleen and caused the lesion of spleen. Thrombosis was found in the pulmonary vascular system, which could be induced by the blocking of blood vessels with TiO2 particles. Moreover, hepatocellular necrosis and apoptosis, hepatic fibrosis, renal glomerulus swelling and interstitial pneumonia associated with alveolar septal thickening were also observed in high-dose groups. Copyright © 2009 John Wiley & Sons, Ltd.
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