Non-porous polyether sulfone hollow fibers(with a 5 μm poly(dimethylsiloxane)coating)were used as structured packing in the distillation of ethanol-water solutions.In this novel membrane contactor,liquid flowed throu...Non-porous polyether sulfone hollow fibers(with a 5 μm poly(dimethylsiloxane)coating)were used as structured packing in the distillation of ethanol-water solutions.In this novel membrane contactor,liquid flowed through the lumens of the fibers,and vapor flowed countercurrently outside the fibers.The results showed that the new membrane contactor gave better,more productive separations than traditional packing in distillation.The minimal HETP of hollow fibers could reach as low as 5.8 cm,and the contactor worked well above the limit where flooding normally occurs in conventional cases.The overall mass-transfer coefficient and individual mass-transfer coefficients based on the gas side and liquid side were calculated respectively.The theoretical analysis indicated that the resistance in the liquid was responsible for more than half of the total resistance.展开更多
采用丙烯酸接枝改性聚丙烯非织造布(PP-g-AA)对阳离子红X-GRL染料进行吸附与解吸,探讨了PP-g-AA对染料的吸附动力学机理、解吸过程和解吸动力学机理,以及基于动态吸附的过滤分离操作,分析了PP-g-AA对染料吸附-解吸再生循环利用的可行性...采用丙烯酸接枝改性聚丙烯非织造布(PP-g-AA)对阳离子红X-GRL染料进行吸附与解吸,探讨了PP-g-AA对染料的吸附动力学机理、解吸过程和解吸动力学机理,以及基于动态吸附的过滤分离操作,分析了PP-g-AA对染料吸附-解吸再生循环利用的可行性。结果表明:不同初始染料浓度下,PP-g-AA的吸附动力学符合Lagergren's准二级动力学模型和双指数模型;解吸液的最佳配比为表面活性剂质量分数5%,乙醇与水的体积比3∶7,解吸率随吸附量的增大呈现先增大后减小的趋势,解吸符合Lagergren's准二级动力学模型;动态吸附-解吸再生循环10次后,染料的去除率达96%以上,再生循环8次时,PP-g-AA的跨膜压力为37.1 k Pa,水通量最大达38.6 L/(m2·h)。展开更多
A novel polyacrylaminothiourea chelating fiber was synthesized simply andrapidly from nitrilon (an acrylonitrile-based synthetic fiber), which was applied to preconcentrateand separate of trace amount of Au(III), Pt(I...A novel polyacrylaminothiourea chelating fiber was synthesized simply andrapidly from nitrilon (an acrylonitrile-based synthetic fiber), which was applied to preconcentrateand separate of trace amount of Au(III), Pt(IV), Pd(IV) and Ir(IV) ions from solution of samples.The analyzed ions can be quantitatively concentrated by the fiber up to a flow rate of 20.0 mL/minat pH 2, and can also be desorbed with 15 mL of 4 mol/L HCl+3% thiourea from the fiber column withrecoveries of 96.5%-100%. The chelating fiber can be reused for ten times, the recoveries of theseions are still over 92%, and hundred to thousand times of excess of Fe(III), Al(III), Ca(II),Mg(II), Ni(II), Mn(II), Cu(II), Zn(II), and Cd(II) cause no interference on the determination of theanalyzed ions by inductively-coupled plasma atomic emission spectrometry (ICP-AES). The staticsaturation adsorption capacities of the fiber for the analytes are in the range of 1.15-2.80 mmol/g.The relative standard deviations for the determination of 20.0 ng/mL each of Au(III), Pt(IV),Pd(IV) and Ir(IV) are in the range of 0.7%-3.0%. The recoveries for test from standard additions toreal solution samples are between 96% and 100%. The concentration of each ion in powder sampledetected by the method is in good agreement with the certified value.展开更多
文摘Non-porous polyether sulfone hollow fibers(with a 5 μm poly(dimethylsiloxane)coating)were used as structured packing in the distillation of ethanol-water solutions.In this novel membrane contactor,liquid flowed through the lumens of the fibers,and vapor flowed countercurrently outside the fibers.The results showed that the new membrane contactor gave better,more productive separations than traditional packing in distillation.The minimal HETP of hollow fibers could reach as low as 5.8 cm,and the contactor worked well above the limit where flooding normally occurs in conventional cases.The overall mass-transfer coefficient and individual mass-transfer coefficients based on the gas side and liquid side were calculated respectively.The theoretical analysis indicated that the resistance in the liquid was responsible for more than half of the total resistance.
文摘采用丙烯酸接枝改性聚丙烯非织造布(PP-g-AA)对阳离子红X-GRL染料进行吸附与解吸,探讨了PP-g-AA对染料的吸附动力学机理、解吸过程和解吸动力学机理,以及基于动态吸附的过滤分离操作,分析了PP-g-AA对染料吸附-解吸再生循环利用的可行性。结果表明:不同初始染料浓度下,PP-g-AA的吸附动力学符合Lagergren's准二级动力学模型和双指数模型;解吸液的最佳配比为表面活性剂质量分数5%,乙醇与水的体积比3∶7,解吸率随吸附量的增大呈现先增大后减小的趋势,解吸符合Lagergren's准二级动力学模型;动态吸附-解吸再生循环10次后,染料的去除率达96%以上,再生循环8次时,PP-g-AA的跨膜压力为37.1 k Pa,水通量最大达38.6 L/(m2·h)。
基金theNaturalScienceFoundationofNingxia ,China (No .199912 )andtheScienceCommitteeFoundationofNingx ia ,China
文摘A novel polyacrylaminothiourea chelating fiber was synthesized simply andrapidly from nitrilon (an acrylonitrile-based synthetic fiber), which was applied to preconcentrateand separate of trace amount of Au(III), Pt(IV), Pd(IV) and Ir(IV) ions from solution of samples.The analyzed ions can be quantitatively concentrated by the fiber up to a flow rate of 20.0 mL/minat pH 2, and can also be desorbed with 15 mL of 4 mol/L HCl+3% thiourea from the fiber column withrecoveries of 96.5%-100%. The chelating fiber can be reused for ten times, the recoveries of theseions are still over 92%, and hundred to thousand times of excess of Fe(III), Al(III), Ca(II),Mg(II), Ni(II), Mn(II), Cu(II), Zn(II), and Cd(II) cause no interference on the determination of theanalyzed ions by inductively-coupled plasma atomic emission spectrometry (ICP-AES). The staticsaturation adsorption capacities of the fiber for the analytes are in the range of 1.15-2.80 mmol/g.The relative standard deviations for the determination of 20.0 ng/mL each of Au(III), Pt(IV),Pd(IV) and Ir(IV) are in the range of 0.7%-3.0%. The recoveries for test from standard additions toreal solution samples are between 96% and 100%. The concentration of each ion in powder sampledetected by the method is in good agreement with the certified value.
