The Experts below are selected from a list of 104586 Experts worldwide ranked by ideXlab platform

Wei Liu - One of the best experts on this subject based on the ideXlab platform.

  • bioleaching assisted foam fractionation for recovery of gold from the printed circuit boards of discarded cellphone
    2020
    Co-Authors: Gang Zhou, Wei Liu, Huixin Zhang, Wei Yang, Chunyan Yang
    Abstract:

    Present work was focused on recovering gold (Au) from the printed circuit boards (PCBs) of discarded cellphone by bioleaching assisted continuous foam fractionation. First, the cyanide-producing strains of Pseudomonas putida and Bacillus megaterium were co-cultured in order to supply a high cyanide concentration in the nutrient solution for mobilizing Au from waste PCBs (WPCBs). Bioleaching conditions were optimized by using response surface methodology. Under the suitable bioleaching conditions of pH of 10.0, pulp density of 5 g/L and leaching time of 34 h, the Au mobilization percentage was 83.59%. The leaching liquor with an Au concentration of 1.34 mg/L could be used as the feeding solution of continuous foam fractionation after removing solid particles and cell biomass. In order to strengthen foam drainage, a novel Internal Component of foam fractionation column was developed. Under the suitable operation conditions of CTAB concentration of 0.2 g/L, volumetric air flow rate of 100 mL/min and feed flow rate of 10 mL/min, the enrichment ratio and recovery percentage of Au were 43.62 and 87.46%, respectively. This study is expected to provide an effective strategy to recover Au from WPCBs, and to supplement the depleting natural resources.

  • foam fractionation for recovering whey soy protein from whey wastewater strengthening foam drainage using a novel Internal Component with superhydrophobic surface
    2017
    Co-Authors: Wei Liu, Mengwei Zhang, Shuai Tian
    Abstract:

    Abstract Whey soy proteins (WSP) are acid soluble proteins massively existed in the whey wastewater from the process of soybean protein isolate (SPI) manufacture and they possess high nutritive values and good functional properties. For effectively recovering WSP from the whey wastewater by using foam fractionation, a novel foam column fitted with the cross Internal covered by a superhydrophobic coating (SHC) was developed to strengthen foam drainage. The experimental results indicated that SHC could significantly strengthen foam drainage through decreasing the flow resistance of the interstitial liquid in the exterior channels at room temperature. The suitable length of the cross Internal with SHC was 600 mm and the drainage velocity was dramatically accelerated when it was installed at 50 mm from the top of the column. Under the suitable operation conditions, enrichment ratio and recovery percentage of WSP reached 10.5 and 82.3%, respectively. This work provides a new light for strengthening foam drainage at room temperature and facilitates of the industrialization of foam fractionation.

Chunyan Yang - One of the best experts on this subject based on the ideXlab platform.

  • bioleaching assisted foam fractionation for recovery of gold from the printed circuit boards of discarded cellphone
    2020
    Co-Authors: Gang Zhou, Wei Liu, Huixin Zhang, Wei Yang, Chunyan Yang
    Abstract:

    Present work was focused on recovering gold (Au) from the printed circuit boards (PCBs) of discarded cellphone by bioleaching assisted continuous foam fractionation. First, the cyanide-producing strains of Pseudomonas putida and Bacillus megaterium were co-cultured in order to supply a high cyanide concentration in the nutrient solution for mobilizing Au from waste PCBs (WPCBs). Bioleaching conditions were optimized by using response surface methodology. Under the suitable bioleaching conditions of pH of 10.0, pulp density of 5 g/L and leaching time of 34 h, the Au mobilization percentage was 83.59%. The leaching liquor with an Au concentration of 1.34 mg/L could be used as the feeding solution of continuous foam fractionation after removing solid particles and cell biomass. In order to strengthen foam drainage, a novel Internal Component of foam fractionation column was developed. Under the suitable operation conditions of CTAB concentration of 0.2 g/L, volumetric air flow rate of 100 mL/min and feed flow rate of 10 mL/min, the enrichment ratio and recovery percentage of Au were 43.62 and 87.46%, respectively. This study is expected to provide an effective strategy to recover Au from WPCBs, and to supplement the depleting natural resources.

Yang Chao - One of the best experts on this subject based on the ideXlab platform.

  • effectsofInternalsonphaseholdupandbackmixinginaslightlyexpandedbedreactorwithgasliquidconcurrentupflow
    2019
    Co-Authors: Yu Kang, Wang Weijie, Zhang Tao, Yong Yumei, Yang Chao
    Abstract:

    Five different Internals were designed, and their effects on phase holdup and backmixing were investigated in a gas–liquid concurrent upflow reactor where the spherical alumina packing particles of three diameters (3.0, 4.5 and 6.0?mm) were slightly expanded under the conditions of varied superficial gas velocities (6.77?×?10 ?2 - 3.61?×?10 ?1 ?m·s ?1 ) and superficial liquid velocities (9.47?×?10 ?4 - 2.17?×?10 ?3 ?m·s ?1 ). The experimental results show that the gas holdup increases with the superficial gas velocity and particle size, opposite to the variational trend of liquid holdup. When an Internal Component is installed amid the upflow reactor, a higher gas holdup, a less liquid holdup and a larger Peclet number characterizing the weaker backmixing are obtained compared to those in the bed without Internals under the same operating conditions. Additionally, the minimal backmixing is observed in the reactor equipped with the Internals with a novel multi-step design. Finally, empirical correlations were proposed for estimating gas holdup, liquid holdup and Peclet number with the relative deviations within 11%, 12% and 25%, respectively

  • Effects of Internals on phase holdup and backmixing in a slightly-expanded-bed reactor with gas-liquid concurrent upflow
    2019
    Co-Authors: Yu Kang, Wang Weijie, Zhang Tao, Yong Yumei, Yang Chao
    Abstract:

    Five different Internals were designed, and their effects on phase holdup and backmixing were investigated in a gas-liquid concurrent upflow reactor where the spherical alumina packing particles of three diameters (3.0, 4.5 and 6.0 mm) were slightly expanded under the conditions of varied superficial gas velocities (6.77 x 10(-2) - 3.61 x 10(-1) m.s(-1)) and superficial liquid velocities (9.47 x 10(-1) - 2.17 x 10(-3) m.s(-1)). The experimental results show that the gas holdup increases with the superficial gas velocity and particle size, opposite to the variational trend of liquid holdup. When an Internal Component is installed amid the upflow reactor, a higher gas holdup, a less liquid holdup and a larger Peclet number characterizing the weaker backmixing are obtained compared to those in the bed without Internals under the same operating conditions. Additionally, the minimal backmixing is observed in the reactor equipped with the Internals with a novel multi-step design. Finally, empirical correlations were proposed for estimating gas holdup, liquid holdup and Peclet number with the relative deviations within 11%, 12% and 25%, respectively. (C) 2019 The Chemical Industry and Engineering Society of China. and Chemical Industry Press Co., Ltd. All rights reserved

Shuai Tian - One of the best experts on this subject based on the ideXlab platform.

  • foam fractionation for recovering whey soy protein from whey wastewater strengthening foam drainage using a novel Internal Component with superhydrophobic surface
    2017
    Co-Authors: Wei Liu, Mengwei Zhang, Shuai Tian
    Abstract:

    Abstract Whey soy proteins (WSP) are acid soluble proteins massively existed in the whey wastewater from the process of soybean protein isolate (SPI) manufacture and they possess high nutritive values and good functional properties. For effectively recovering WSP from the whey wastewater by using foam fractionation, a novel foam column fitted with the cross Internal covered by a superhydrophobic coating (SHC) was developed to strengthen foam drainage. The experimental results indicated that SHC could significantly strengthen foam drainage through decreasing the flow resistance of the interstitial liquid in the exterior channels at room temperature. The suitable length of the cross Internal with SHC was 600 mm and the drainage velocity was dramatically accelerated when it was installed at 50 mm from the top of the column. Under the suitable operation conditions, enrichment ratio and recovery percentage of WSP reached 10.5 and 82.3%, respectively. This work provides a new light for strengthening foam drainage at room temperature and facilitates of the industrialization of foam fractionation.

Jacobs Zenobia - One of the best experts on this subject based on the ideXlab platform.

  • Calibration of a QEM-EDS system for rapid determination of potassium concentrations of feldspar grains used in optical dating
    2021
    Co-Authors: O\u27gorman Kieran, Brink Frank, Tanner Dominique, Jacobs Zenobia
    Abstract:

    © 2020 Elsevier B.V. Potassium (K)-rich feldspars are one of two mineral types typically used for optical dating. Feldspar grains can contain up to ~14 wt% K that gives rise to an Internal dose rate Component. This Internal Component can comprise a significant proportion of the total environmental dose rate to which a mineral grain is exposed. The environmental dose rate term—the denominator in the optical age equation—determines the rate at which electronic charge is transferred into the crystal lattice of a mineral grain over its period of burial. Not all feldspar grains have the same K concentration, so Internal dose rates differ between individual grains. K concentrations can range from 0 to 14 wt% due to the variable compositions of feldspar phases, differing proportions of discrete feldspar phases and/or the presence of other mineral inclusions in grains. Numerous techniques are available for determining the K concentrations of individual grains, but are time-consuming, and either lack the spatial resolution to classify discrete mineral phases within multi-phase grains, or the coverage to obtain whole-of-grain average K concentrations. Quantitative evaluation of minerals using energy dispersive spectroscopy (QEM-EDS) is a time-efficient and automated mapping technique that has the spatial resolution to classify most mineral phases, as well as the coverage to determine their area proportions. QEM-EDS can also be used to determine elemental concentrations based on spectral matches to EDS reference spectra. It is, however, difficult to determine accurate elemental concentrations for minerals such as feldspars, where solid solutions exist. To overcome this, we establish a QEM-EDS calibration using EDS spectra from six feldspar reference standards to define five solid solution regions along the alkali and plagioclase feldspar series. We test this calibration through comparisons of the K concentrations of discrete phases of three feldspar varieties (orthoclase/microcline, albite and sanidine), derived using both QEM-EDS and wavelength dispersive spectroscopy (WDS). We assume that the WDS-derived K concentrations represent the ‘true’ K concentrations of the phases, and calculate, from a best-fit weighted regression of the two data sets, a correction and uncertainty estimate that can be applied to the QEM-EDS-derived K concentrations, taking into account instrument irreproducibility and any measurement bias. We also test alternative mapping step sizes to optimise efficiency, and apply this time-efficient technique to individual luminescent feldspar grains from two samples. We propose that QEM-EDS is capable of (1) classifying the range of mineral phases in grains, (2) determining the area proportions of each of these phases, and (3) obtaining accurate whole-of-grain average K concentrations of individual feldspar grains using the calibration and correction presented here

  • Calibration of a QEM-EDS system for rapid determination of potassium concentrations of feldspar grains used in optical dating
    2021
    Co-Authors: O\u27gorman Kieran, Brink Frank, Tanner Dominique, Jacobs Zenobia
    Abstract:

    Potassium (K)-rich feldspars are one of two mineral types typically used for optical dating. Feldspar grains can contain up to ~14 wt% K that gives rise to an Internal dose rate Component. This Internal Component can comprise a significant proportion of the total environmental dose rate to which a mineral grain is exposed. The environmental dose rate term—the denominator in the optical age equation—determines the rate at which electronic charge is transferred into the crystal lattice of a mineral grain over its period of burial. Not all feldspar grains have the same K concentration, so Internal dose rates differ between individual grains. K concentrations can range from 0 to 14 wt% due to the variable compositions of feldspar phases, differing proportions of discrete feldspar phases and/or the presence of other mineral inclusions in grains. Numerous techniques are available for determining the K concentrations of individual grains, but are time-consuming, and either lack the spatial resolution to classify discrete mineral phases within multi-phase grains, or the coverage to obtain whole-of-grain average K concentrations. Quantitative evaluation of minerals using energy dispersive spectroscopy (QEM-EDS) is a time-efficient and automated mapping technique that has the spatial resolution to classify most mineral phases, as well as the coverage to determine their area proportions. QEM-EDS can also be used to determine elemental concentrations based on spectral matches to EDS reference spectra. It is, however, difficult to determine accurate elemental concentrations for minerals such as feldspars, where solid solutions exist. To overcome this, we establish a QEM-EDS calibration using EDS spectra from six feldspar reference standards to define five solid solution regions along the alkali and plagioclase feldspar series. We test this calibration through comparisons of the K concentrations of discrete phases of three feldspar varieties (orthoclase/microcline, albite and sanidine), derived using both QEM-EDS and wavelength dispersive spectroscopy (WDS). We assume that the WDS-derived K concentrations represent the ‘true’ K concentrations of the phases, and calculate, from a best-fit weighted regression of the two data sets, a correction and uncertainty estimate that can be applied to the QEM-EDS-derived K concentrations, taking into account instrument irreproducibility and any measurement bias. We also test alternative mapping step sizes to optimise efficiency, and apply this time-efficient technique to individual luminescent feldspar grains from two samples. We propose that QEM-EDS is capable of (1) classifying the range of mineral phases in grains, (2) determining the area proportions of each of these phases, and (3) obtaining accurate whole-of-grain average K concentrations of individual feldspar grains using the calibration and correction presented here