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Cong H.,Chemical Engineering Research Center
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2010

The selective removal of low density lipoprotein (LDL) and fibrinogen (Fib) by degraded carrageenan was studied by the present authors. Degraded carrageenan was prepared by acid with carrageenan as the main material. The effects of acid conditions on the molecular weight were investigated, and the proper reaction conditions were ascertained. The results of infrared spectrometry indicated that the degraded carrageenan is a heparin-like polysaccharide. Then the selective removal of LDL/Fibrinogen by degraded carrageenan was studied. When molecular weight was about 10,000, pH was 5.10 and the concentration of degraded carrageenan was 800 mg/L, the average reduction percentages were 60.0% for total cholesterol(TC), 79.4% for LDL and very low-density lipoprotein (VLDL), and 93.8% for fibrinogen. There were no significant changes with relation to the level of high-density lipoprotein (HDL) and total protein (TP). So, degraded carrageenan was shown to be of good selectivity on plasma LDL/Fibrinogen apheresis. Source

Cong H.,Chemical Engineering Research Center
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2010

A hydrophobic low-density lipoprotein cholesterol (LDL-C) adsorbent was synthesized with lauric acid and chitosan. The condition for adsorption was obtained by investigating the influence of adsorbent amount and adsorption time. The results of adsorption in vitro showed that the average adsorption rates for total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C) and total protein (TP) were 47.7%, 84.7%, 18.1% and 5.9% respectively. The adsorbent possesses good selectivity in removing LDL-C. Source

Feng F.,East China University of Science and Technology | Feng F.,Chemical Engineering Research Center | Xu Z.,East China University of Science and Technology | Xu Z.,Chemical Engineering Research Center | And 3 more authors.
Journal of Environmental Sciences | Year: 2010

The performance of combined Fenton oxidation and membrane bioreactor (MBR) process for the advanced treatment of an effluent from an integrated dyeing wastewater treatment plant was evaluated. The experimental results revealed that under the optimum Fenton oxidation conditions (initial pH 5, H2O2 dosage 17 mmol/L, and Fe2+ 1.7 mmol/L) the average total organic carbon (TOC) and color removal ratios were 39.3% and 69.5% after 35 min of reaction, respectively. Results from Zahn-Wallens Test also represented that Fenton process was effective to enhance the biodegradability of the test wastewater. As for the further purification of MBR process, TOC removal capacity was examined at different hydraulic retention times (HRT) of 10, 18 and 25 hr. Under the optimum HRT of 18 hr, the average TOC concentration and color of the final MBR effluent were 16.8 mg/L and 2 dilution time, respectively. The sludge yield coefficient was 0.13 g MLSS/g TOC and TOC degradation rate was 0.078 kg TOC/(m3·day). The final effluent of MBR can meet the reuse criteria of urban recycling water - water quality standard for miscellaneous water consumption GBT18920-2002. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Source

Li Q.,East China University of Science and Technology | Li Q.,Chemical Engineering Research Center | Xu Z.-L.,East China University of Science and Technology | Xu Z.-L.,Chemical Engineering Research Center | Yu L.-Y.,Chemical Engineering Research Center
Journal of Applied Polymer Science | Year: 2010

Polyvinylidene fluoride (PVDF) microporous flat membranes were cast with different kinds of PVDFs and four mixed solvents [trimethyl phosphate (TMP) - N,N - dimethylacetamide (DMAc), triethyl phosphate (TEP) - DMAc, tricresyl phosphate (TCP) - DMAc, and tri - n - butyl phosphate (TBP) - DMAC]. The effects of different commercial PVDFs (Solef® 1015, FR 904, Kynar 761, Kynar 741, Kynar 2801) on membrane morphologies and membrane performances of PVDF/TEP - DMAc/PEG200 system were investigated. The membrane morphologies were examined by scanning electron microscopy (SEM). The membrane performances in terms of pure water flux, rejection, porosity, and mean pore radius were measured. The membrane had the high flux of 143.0 ± 0.9 L m - 2 h - 1 when the content of TMP in the TMP - DMAc mixed solvent reached 60 wt %, which was 2.89 times that of the membrane cast with DMAc as single solvent and was 3.36 times that of the membrane cast with TMP as single solvent. Using mixed solvent with different solvent solubility parameters, different morphologies of PVDF microporous membranes were obtained. TMP - DMAc mixed solvent and TEP - DMAc mixed solvent indicated the stronger solvent power to PVDF due to the lower solubility parameter difference of 1.45 MPa1/2 and the prepared membranes showed the faster precipitation rate and the higher flux. The less macrovoids of the membrane prepared with TEP (60 wt %) - DMAc (40 wt %) as mixed solvent contributed to the higher elongation ratio of 96.61% ± 0.41%. Therefore, using TEP(60 wt %) - DMAc (40 wt %) as mixed solvent, the casting solution had the better solvent power to PVDF,andthemembranepossessedtheexcellentmechanical property. The microporous membranes prepared from casting solutions with different commercial PVDFs exhibited similar morphology, but the water flux increased with the increment of polymer solution viscosity. © 2009 Wiley Periodicals, Inc. Source

Qin Y.,Chemical Engineering Research Center | Qin Y.,Tianjin University of Technology | Li B.,Chemical Engineering Research Center | Li B.,Tianjin University of Technology | Wang S.,Chemical Engineering Research Center
Industrial and Engineering Chemistry Research | Year: 2012

Plastic heat exchangers have attracted more and more attention because of their superior resistance to chemicals and fouling.However, the thermal conductivity of plastic materials is much lower than that of metal, which limits the wider application of plastic heat exchangers. In this study, polypropylene-based hollow fibers as a heat-conducting medium for heat exchangers was developed by melt-mixing polypropylene with graphite particles and maleated polypropylene (PP-g-MA). Results show that the addition of graphite fairly improved the crystalline, thermal stability and conductivity of the polypropylene resin and further improved the heat transfer efficiency of polypropylene-based hollow fiber heat exchangers. The overall heat transfer coefficient of 15.0 wt % graphite modified polypropylene hollow fiber heat exchangers reached 1228.7 W/(m2 3 K), which is 5 times higher than that of pure PP-based hollow fiber heat exchangers, and the overall conductance per unit volume reached 1.1 × 10 6 W/(m 3 · K). Further, the heat transfer efficiency increases fairly with the increase of the fluid flow rate, especially with the flow rate of the tubeside. The optimized operation mode is that the hot water flows on the tube-side and the cold water flows on the shell-side. © 2011 American Chemical Society. Source

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