显示样式:     当前期刊: Separation and Purification Technology    加入关注       排序: 导出
我的关注
我的收藏
您暂时未登录!
登录
  • Enantioselective liquid-liquid extraction of amino acid enantiomers using (S)-MeO-BIPHEP-metal complexes as chiral extractants
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-25
    Xiong Liu, Yu Ma, Ting Cao, Danni Tan, Xinyu Wei, Jin Yang, Lin Yu

    (S)-MeO-BIPHEP-metal complexes were firstly used as chiral extractants to separate amino acid enantiomers. Six amino acid enantiomers were employed to evaluate the stereoselectivities of (S)-MeO-BIPHEP-metal complexes. The results revealed that (S)-MeO-BIPHEP-Cu complex exhibited good abilities to separate phenylalanine (Phe), phenylglycine (Pheg), tyrosine (Tyr) and 3-chloro-phenylglycine (Cpheg) enantiomers with operational enantioselectivities (α) were 2.56, 2.24, 4.22 and 1.81, respectively. While (S)-MeO-BIPHEP-Pd complex exhibited good ability to separate 4-nitro-phenylalanine (Nphe) with operational enantioselectivity (α) was 3.87. All of (S)-MeO-BIPHEP-metal complexes showed poor abilities to separate homophenylalanine (Hphe) with α below 1.5. The influences of extraction temperature, concentrations of (S)-MeO-BIPHEP-metal complexes and pH of aqueous phase on extractions were systematically investigated. On the basis of single-factor experiments, the extraction conditions of separating Phe, Pheg, Nphe, Tyr and Cpheg were optimized by response surface methodology. After optimization, the maximum performance factors (pf) for Phe, Pheg, Nphe, Tyr and Cpheg were 0.11865, 0.13487, 0.17706, 0.21882 and 0.13579, respectively.

    更新日期:2018-09-25
  • Multi-Component (Cu,Mn)(Se,S) Nanosheet Catalysts for Redox Reactions in the Dark
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-22
    Xiaoyun Chen, Dong-Hau Kuo, Zong-Yan Wu, Jubin Zhang, Yuanbo Guo, Huizhi Sun, Jinguo Lin
    更新日期:2018-09-25
  • Impact of a high hydrostatic pressure pretreatment on the separation of bioactive peptides from flaxseed protein hydrolysates by electrodialysis with ultrafiltration membranes
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-22
    Gina Cecile Urbain Marie, Véronique Perreault, Loïc Henaux, Valérie Carnovale, Rotimi Aluko, André Marette, Alain Doyen, Laurent Bazinet

    High hydrostatic pressure (HHP) and electrodialysis with ultrafiltration membranes (EDUF) are two efficient technologies used respectively to improve protein enzymatic hydrolysis and recovery of bioactive peptides, but they have never been tested together. Hence, in this study, HHP pre-treatment was performed on defatted flaxseed protein isolate prior to enzymatic hydrolysis and the resulting peptides were separated by EDUF. HHP pretreatment influenced particle size, protein conformation, and degree of hydrolysis. After EDUF separation, peptide fractions (generated after enzymatic hydrolysis of control and pressure-treated protein isolate) recovered in KCl fraction were enriched in arginine and associated with a decrease in systolic blood pressure (SBP) in spontaneously hypertensive rats. Additionally, the final EDUF hydrolysate generated from pretreated protein and the initial EDUF hydrolysate from native protein were also associated with lower SBP. However, only the control KCl fraction obtained from native protein hydrolysate was associated with anti-diabetic activity.

    更新日期:2018-09-25
  • Integrating ZVI-dehalogenation into an electrolytic soil- washing cell
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-22
    C. Carvalho de Almeida, M. Muñoz-Morales, C. Sáez, P. Cañizares, C.A. Martínez-Huitle, M.A. Rodrigo

    Combination into a single electrochemical reactor of soil washing, ZVI dehalogenation and anodic oxidation can be used to degrade directly the clopyralid contained in spiked soil. Treatment is efficient, achieving the complete removal of chlorinated organics as well as the complete mineralization of the liquid waste produced. However, this combined process does not seem to improve the efficiency with respect to a system operated without addition of iron. Results show that the dechlorinated intermediates formed are less reactive than the parent pollutants, being particularly important the formation of oxalic acid, because its combination with iron (II) helps to explain the decrease in the overall rate of mineralization. This negative impact on the efficiency of the electrochemical process is not completely undesirable, because the toxicity of the waste decreases importantly in the very early stages with the use of iron, opening the possibility of a combination with biological treatments. Again, the accumulation of oxalate intermediates helps to explain this conclusion. Results point out the important effect of the size of iron particles used on the treatment and the complexity of the mechanisms that develop in the cell, which are explained in terms of the different parameters monitored.

    更新日期:2018-09-25
  • A dually charged nanofiltration membrane by pH-responsive polydopamine for pharmaceuticals and personal care products removal
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-24
    Zhiyu Ouyang, Zhonghua Huang, Xinyuan Tang, Caihua Xiong, Mengdi Tang, Yuting Lu
    更新日期:2018-09-25
  • 更新日期:2018-09-22
  • 更新日期:2018-09-22
  • Electrokinetic-assisted phytoremediation of atrazine: differences between electrode and interelectrode soil sections
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-21
    Virtudes Sánchez, Francisco Javier López-Bellido, Manuel Andrés Rodrigo, Luis Rodríguez
    更新日期:2018-09-22
  • Preparation and characterization of palladium/polyaniline/foamed nickel composite electrode for electrocatalytic dechlorination
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-21
    Junjing Li, Cong Luan, Yuqi Cui, Huixuan Zhang, Liang Wang, Huan Wang, Zhaohui Zhang, Bin Zhao, Hongwei Zhang, Xinyi Zhang, Xiuwen Cheng

    In the present work, palladium/polyaniline/foamed nickel (Pd/PANI/Ni) composite electrode was successfully constructed via two-step galvanostatic electropolymerization method. Subsequently, physicochemical properties such as apparent morphologies, crystalline structure, surface state and electrochemical property were characterized through scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Electrochemical impedance spectroscopy (EIS). The effects of the polymerization current, temperature and reaction time of galvanostatic electropolymerization on the composite electrode for the electrochemical dechlorination of 2,4-dichlorophenol (2,4-DCP) were examined. All results indicated that PANI in the Pd/PANI/Ni composite electrode existed in the form of needle-shaped, while nulvalent Pd particles dispersed well as clusters in the network on PANI. Under optimal conditions, in which PANI polymerized on electrode structure with the polymerization current of 24 mA, temperature of 0 °C and time of 20 min, respectively, a 89.1% removal rate of 2,4-DCP could be achieved. Finally, electrochemical dechlorination pathway was investigated and the main dechlorination product was phenol. The composite electrode possessed good stability and excellent electrocatalytic dichlorination performance.

    更新日期:2018-09-21
  • 更新日期:2018-09-21
  • Treatment of landfill leachate using different configurations of ultrasonic reactors combined with advanced oxidation processes
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-20
    Saurabh M. Joshi, Parag R. Gogate

    Treatment of leachate generated from municipal solid waste using different configurations of ultrasonic (US) reactors in combination with advanced oxidation processes based on ozone, hydrogen peroxide (H2O2) and Fenton has been investigated in the present work. US configurations investigated were US horn, US flow cell and US bath with variation in mode of irradiation, operating volume and power consumption. The different approaches investigated were only US, US combined with ozone (US/O3), US/H2O2 and US/Fenton at different loadings. For the case of US horn, the obtained extents of COD removal were 6, 24.5, 42 and 73 % for different approaches of only US, US+ ozone, US+ H2O2 (5 g/L as the loading) and US+ Fenton (Fe2+/ H2O2 molar ratio as 1:10) respectively. US flow cell gave extent of COD removal as 44, 50, 72 and 92 % when operated in different approaches as only US, US+ Ozone, US+ H2O2 (5 g/L as the loading) and US+ Fenton (Fe2+/ H2O2 molar ratio as 1:10) respectively. US bath operated under optimized parameters established from studies in US flow cell as H2O2 loading of 5 g/L and Fe2+/ H2O2 ratio of 1:10 resulted in COD removal of 90 %. Synergetic coefficient and biodegradability index (BI) were also calculated and the most effective process established was US flow cell+ Fenton with maximum COD removal of 92 % with increased BI from 0.36 to 0.55 and synergetic coefficient of 3.17. Energy efficiency and cost calculations for the US flow cell and US bath with Fenton established that treatment cost was 28.7 and 25 US$/m3 respectively. Overall the combination of US flow cell with Fenton has been established as the most viable approach for leachate treatment.

    更新日期:2018-09-21
  • Vacuum membrane distillation for the treatment of coffee products
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-20
    A. Criscuoli, E. Drioli

    Vacuum Membrane Distillation (VMD) was applied in two production lines of the coffee industry: the concentration of the coffee extract and the dehydration and recovery of caffeine.Experiments were carried out by using a commercial flat microporous membrane made of polypropylene (0.2 μm pore size). Both systems worked with a vacuum value of 4 mbar, while the temperature was fixed at 45°C and at 27°C for the caffeine recovery and the coffee extract concentration, respectively. Starting from an extract of 13 wt%, it was possible to concentrate it up to the values needed for the instantaneous/soluble coffee prouction, while dry caffeine was recovered from a 0.1-0.3 wt% aqueous feed. In both case studies, a pure distillate stream, able to be re-used in the plant, was obtained.

    更新日期:2018-09-21
  • A new method for simultaneous removal of heavy metals and harmful organics from rape seed meal from metal-contaminated farmland
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-19
    Yuan Jing, Yang Yang, Zhou Xi-hong, Ge Yi-cheng, Zeng Qing-ru

    Phytoremediation is a promising, cost-effective technique for remediating soil contaminated by heavy metals. When using this approach, however, much contaminated plant material will necessarily be generated that cannot be properly treated after the phytoextraction process. This remains an unsolved problem and thus a major hurdle for the commercial implementation of phytoremediation. This study’s main objective was to remove several heavy metals and harmful organics from rape seed meal via hydrochloric with 70% alcohol extraction under different experimentally controlled conditions, namely the extraction concentrations, the reaction time and temperature, and the extraction steps. Our results showed the following: (1) Removal of heavy metals was increased by raising the temperature, or extractant concentrations, or successive extraction steps. The highest extraction efficiency was attained with 1% hydrochloric acid at 25°C for 12 h after three successive extractions; under this condition, the removal of Pb, Zn, Cu, and Cd, respectively, reached 89.1%, 93.9%, 92.3%, and 99.3%. (2) After three successive extractions using 0.5% hydrochloric acid, at 25°C for 12 h, the concentrations of Cd and Pb in rape seed meal were 0.028 and 2.75 mg kg-1, respectively, which met the current Chinese feed safety standards. Thus, 0.5% hydrochloric acid for the extraction of heavy metals in rape seed meal is economically appropriate. (3) Extraction using hydrochloric acid left little harmful organics rape seed meal, but it little lowered the concentrations of six nutrient elements. The removal of phytic acid, tannins, and glucosinolates, respectively, reached 99.2%, 50.0%, and 85.6%. Importantly, crude protein content as a nutrient was reduced by just 1.4%. In general, hydrochloric extraction is a very thorough cost-benefit method for removing heavy metals from rape seed meal.

    更新日期:2018-09-20
  • Iron oxide (FeO) nanoparticles embedded thin-film nanocomposite nanofiltration (NF) membrane for water treatment
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-19
    Sonia R. Lakhotia, Mausumi Mukhopadhyay, Premlata Kumari
    更新日期:2018-09-20
  • Extraction of cobalt (II) using ionic liquid-based bi-phase and three-phase systems without adding any chelating agents with new recycling procedure
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-19
    Jolanta Flieger, Małgorzata Tatarczak-Michalewska, Eliza Blicharska, Anna Madejska, Wojciech Flieger, Agnieszka Adamczuk
    更新日期:2018-09-20
  • Investigation the photocatalytic activity of CoFe2O4/ZnO and CoFe2O4/ZnO/Ag nanocomposites for purification of dye pollutants
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-19
    E. Ferdosi, H. Bahiraei, D. Ghanbari

    Magnetically separable CoFe2O4/ZnO and CoFe2O4/ZnO/Ag nanocomposites were successfully synthesized using CoFe2O4 nanoparticle as core by a simple precipitate route. The structural, morphology and functionality of prepared samples were analyzed using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy, and vibration sample magnetometer. The micro-structural study approved that the synthesized nanoparticles have spherical morphologies with average particle size between 30-47 nm. The influence of nanocomposites on the acid violet and acid brown degradation was investigated under ultraviolet light. The CoFe2O4/ZnO nanocomposite showed enhanced photocatalytic activity, achieving acid violet and acid brown degradation efficiency of 76% and 63% respectively, rather than other samples. The increase in photocatalytic activity of CoFe2O4/ZnO hybrid may be associated with the formation of a suitable internal structure between CoFe2O4 and ZnO. Magnetic measurement indicated that CoFe2O4/ZnO is ferromagnetic with the magnetization saturation value of 25 emu/g, which is suitable for magnetic recovery by using an external magnetic field.

    更新日期:2018-09-20
  • Rapid degradation of aniline by peroxydisulfate activated with copper-nickel binary oxysulfide
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-20
    Junyi Zhu, Cheng Chen, Yuxin Li, Lixiang Zhou, Yeqing Lan
    更新日期:2018-09-20
  • High-efficient synergistic extraction of Co(II) and Mn(II) from wastewater via novel microemulsion and annular centrifugal extractor
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-20
    Xiaoyong Yang, Fengping Jie, Bingjie Wang, Zhishan Bai

    Environmental pollution by industrial effluents polluted with hazardous heavy metals has great concern. A novel microemulsion system (sodium dodecanoate/pentan-1-ol/heptane/NaCl) was prepared for the treatment of cobalt (Co) and manganese (Mn) wastewater. The effects of the batch extraction conditions were systematically studied and the extraction efficiency of Co(II) and Mn(II) were 98.2% and 97.5% respectively at the optimal conditions. Utilizing the centrifugal reinforcement of the annular centrifugal extractor (ACE), the continuous extraction of cobalt and manganese wastewater by microemulsion could be achieved. Under the optimized operation conditions: the motor speed of 1988 rpm, a flow ratio of 1/5, and a total flow rate of 48 L/h, the maximum extraction efficiency reached up to 99.9% for Co(II) and 99.1% for Mn(II), respectively. The stripping of Co(II) and Mn(II) from the microemulsion phase was also conducted using hydrogen chloride solution, indicating a high stripping efficiency. The investigation of synergistic extraction with microemulsion and ACE proposed an efficient treatment for Co and Mn wastewater.

    更新日期:2018-09-20
  • Highly Conductive Anion Exchange Membranes with Low Water Uptake and Performance Evaluation in Electrodialysis
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-18
    Liang Hao, Junbin Liao, Yuanwei Liu, Huimin Ruan, Arcadio Sotto, Bart Van der Bruggen, Jiangnan Shen

    The present work reports the preparation of a series of novel highly durable imidazolium-decorated anion exchange membranes (AEMs), with 3D network structure, via ultraviolet crosslinking reaction between 1-vinylimidazole and 1,6-hexanedithiol. AEM modified with trimethylamine (TMA) groups (no crosslinking, 45.7%) showed a significantly reduced water uptake within a range of 14.4%–23.6% at 80°C. Due to relatively good alkali-resistant of imidazolium groups and the compact structure stemmed from crosslinking network, the optimum cross-linked AEM (BPPO-Im 0.3) can retard the degradation and exhibits superior alkaline stability in 1.0 M NaOH at 60 oC for over 15 days, compared with TMA modified AEM. In ED application, BPPO-Im 0.3 AEM has a higher NaCl removal ratio of 77.82% than that of commercial AEM-Type II (74.13%) within 3 h experimental time. Accordingly, it shows higher current efficiency (67.43%) and lower energy consumption (1.94 kWh kg–1 NaCl), compared to commercial one (62.83%; 2.05 kWh kg–1). The facile fabrication process and the better-performance are suggestive of that BPPO-Im 0.3 is potentially applicable in ED.

    更新日期:2018-09-19
  • Sugaring-out extraction combining crystallization for recovery of succinic acid
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-18
    Yaqin Sun, Xingxing Zhang, Yafeng Zheng, Ling Yan, Zhilong Xiu

    In this study, sugaring-out extraction combining crystallization was developed for succinic acid separation and purification. From the different sugaring-out extraction systems investigated, the following order in the phase forming ability of the solvents and sugars were observed: t-butanol>n-propanol >isopropanol, and galactose>glucose>fructose>mannose ≈ sucrose>xylose, respectively. Tert-butanol/glucose system showed the potential superiority in the partition behavior of succinic acid, glucose and solvent. The system parameters influencing the extraction efficiency, such as tie line length, system pH, temperature, glucose, t-butanol and succinic acid concentration were evaluated. The results showed that partition coefficient of succinic acid increased linearly as tie line length increased, and strongly depend on the system pH. 88.15% of succinic acid and 96.72% of t-butanol was distributed into the top phase while 94.69% of glucose into the bottom phase at a system consisting of 27% (w/w) glucose and 40% (w/w) t-butanol under pH 3.0 and temperature 25 oC. Succinic acid concentration had influence on its partition behavior due to its broadened scope of phase formation. The effect of temperature in the t-butanol/glucose system was not obvious for partition of succinic acid. Salts-assisted sugaring-out extraction of succinic acid in t-butanol-glucose system was also investigated. When the mass fraction of (NH4)2SO4 was increased from 1% to 9% (w/w), the recovery of SA from the broth increased from 87.62% to 89.55%. It was noteworthy that t-butanol recovery increased obviously from 96.21% to 99.48%, which means almost all of t-butanol was recovered to the top phase. . Finally, succinic acid purification was developed by gradient crystallization after recovering t-butanol by vacuum distillation and glucose by water-washing. By combining sugaring-out extraction with gradient crystallization, an identical total yield (73%) and a higher purity (98%) of succinic acid were obtained. The results obtained in this work support the establishment of sugaring-out extraction combining crystallization as a potential effective and economic strategy for bio-succinic acid separation.

    更新日期:2018-09-19
  • Activation effect of lead ions on scheelite flotation: Adsorption mechanism, AFM imaging and adsorption model
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-18
    Liuyang Dong, Fen Jiao, Wenqing Qin, Hailing Zhu, Wenhao Jia
    更新日期:2018-09-19
  • A Comparative Study on Experimental and Response Surface Optimization of Lactic Acid Synergistic Extraction using Green Emulsion Liquid Membrane
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-18
    Anil Kumar, Avinash Thakur, Parmjit Singh Panesar

    A comparative study on the optimization of various operating variables of lactic acid (LA) synergistic extraction through an environment-friendly green emulsion liquid membrane (GELM) using experimental and response surface optimization has been done. The comparison between response surface methodology (RSM) and experimentally optimized values has been achieved by optimizing various operating variables (internal phase concentration, LA concentration, extractant concentration, emulsification time, treat ratio, phase ratio, agitation speed, and stirring time). The formulation of GELM organic phase constituents was done by using rice bran oil (RBO) as a green solvent, hexane as a diluent, span 80 as a surfactant, tridodecylamine (TDDA) and Aliquat336 as extractants, and NaOH as a stripping phase reagent. A better GELM stability during the LA extraction process was obtained by using the combination of RBO, TDDA, Aliquat336, and span 80. This study has shown a good agreement among all the values excluding the LA concentration and emulsification time. Hence, this present finding has indicated that RBO possesses the high potential to be utilized in the several standing ELM operations for lessening the use of toxic and costly petroleum-based organic solvents.

    更新日期:2018-09-18
  • Hydrometallurgical valorization of chromium, iron, and zinc from an electroplating effluent
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-18
    Ayesha Ishfaq, Sadia Ilyas, Arslan Yaseen, Muhammad Farhan

    Hydrometallurgical removal of heavy metals (like chromium, iron, and zinc) from an industrial effluent, and their valorization into less-toxic species has been studied. At first, the solvent extraction of Cr(VI) was investigated with tri-butyl phosphate (TBP) to separate this carcinogenic metal from an electroplating effluent containing 3.43 g·L−1 Cr, 1.3 g·L−1 Zn, 0.41 g·L−1 Fe, and 1.23 mol·L−1 free acid of chloride medium. The study based on parametric variation revealed the spontaneity in adduct formation (HCrO3Cl·2TBP) into organic phase through the exothermic extraction process (ΔH°, −18.8 kJ·mol−1). The extracted species of Cr(VI) was efficiently stripped (∼99%) as less-toxin Cr(III) by 30 min of contact with 2.0 mol·L−1 ascorbic acid solution. Thereafter, the hydrolytic precipitation of Cr(III) from stripped solution at pH ∼9.0, and Fe(III) from raffinate at pH 3.5 under continuous air-flow could yield the precipitates of Cr(OH)3 and FeOOH·2H2O, respectively. From the Fe-removed solution, a 5% stoichiometric excess of oxalic acid could effectively precipitate > 99.8% zinc in 30 min at 50 °C.

    更新日期:2018-09-18
  • An Experimental Investigation into the Particle Classification Capability of a Novel Cyclone Separator
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-17
    Mehmet Erman Caliskan, Irfan Karagoz, Atakan Avci, Ali Surmen

    Cyclone separators are widely used for dedusting of particle-laden flows in many branches of industry. A new cyclone containing several collectors was designed in modular structure to investigate the capability of particle classification of the cyclone during particle separation process. The particulate air was supplied into the cyclone in a test bench operated in suction mode under ambient temperature and atmospheric pressure conditions. The flow rate and pressure drop were measured, and the particles accumulated in the dust collectors were weighed and analyzed for each test. The changes in the overall collection efficiency and pressure drop with the flow rate were obtained. In order to determine the classification characteristics of the cyclone, the experiments were repeated in different configurations obtained by changing the locations and number of the collectors. The mean particle diameter and particle size distribution of the dust collected in each collector were acquired. Analysis of the results shows that the designed cyclone is capable of classification incoming particles into 2, 3 or 4 classes in the cyclone according to particle size. Classification performance of the configurations and influences of flow rate on this performance were also investigated. A distinct and satisfactory classification was obtained in the configuration with three collectors.

    更新日期:2018-09-18
  • Improvement of MWCO determination by using branched PEGs and MALDI method
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-17
    Alexey Yushkin, Roman Borisov, Vladimir Volkov, Alexey Volkov
    更新日期:2018-09-18
  • 更新日期:2018-09-18
  • Separation of ultrafine ceria-based abrasive particles from glass polishing powder waste through liquid–liquid–powder extraction
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-18
    Li Pang Wang, Yan Jhang Chen, Yu Hua Jiang, Yun Chen Tso

    Glass polishing powder waste comprises ultrafine particles of ceria-based abrasive and polished glass powder. This study investigated the separation of ceria-based abrasive particles from glass polishing powder waste through liquid–liquid–powder extraction. Kerosene was used as the oil phase, and sodium oleate (NaOL) was used as the surfactant collector. First, the properties of the ceria-based abrasive/glass powder particles transferred from the water phase to the kerosene phase and the effect of surfactant collector addition were investigated individually. Then, separation of ceria-based abrasive from an artificial particle mixture of ceria-based abrasive and glass powder was carried out to determine the optimal extraction conditions. Finally, the method was applied to a glass polishing powder waste.The results indicated that with the addition of 2 kg/ton NaOL, more than 90% of the ceria-based abrasive particles were extracted from the water phase to the kerosene phase at a pH of 5–9. The pH and NaOL addition had negligible effect on the extracted fraction of the glass powder, which remained at approximately 10%–15%. The optimal extraction conditions for the separation of ceria-based abrasive from an artificial particle mixture of ceria-based abrasive and glass powder were obtained at pH 7. Both the grade and recovery of the ceria-based abrasive in the kerosene phase solid were higher than 90% when more than 5 kg/ton NaOL was added. With the addition of 10 kg/ton NaOL, the grade was 98.5% and recovery was 97.1%. Similar results were obtained after applying this technique to a glass polishing powder waste.

    更新日期:2018-09-18
  • Pyrrolidinone-based hypercrosslinked polymers for reversible capture of radioactive iodine
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-14
    Xuemei Li, Gang Chen, Jiutong Ma, Qiong Jia
    更新日期:2018-09-15
  • Effect of different additives on the physicochemical properties and performance of NLDH/PVDF nanocomposite membrane
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-14
    Samira Arefi Oskoui, Vahid Vatanpour, Alireza Khataee

    The main objective of this research was to introduce an appropriate additive for improving the properties and performance of the NLDH/PVDF nanocomposite ultrafiltration membrane. For this purpose, the effects of the different additives including hydrophilic polymers e.g. PVP (with molecular weight of 10000 and 29000) and PEG (with molecular weight of 1500 and 6000) and amphiphilic copolymer e.g. pluronic F-127 were investigated on the properties and performance of NLDH/PVDF nanocomposite membrane. The properties of the fabricated membranes were studied using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM) and water contact angle techniques. Moreover, the pure water flux, water flux of BSA solution and flux recovery ratio (FRR) were determined for fabricated membranes in order to investigate their permeability and antifouling property. The results indicated that there was an interaction between the NLDH nanolayers and additive molecules, and so the effect of both NLDH and additive should be simultaneously considered. The results obtained from analysis techniques indicated that the surface porosity, average surface pore size, surface hydrophilicity and cross-sectional morphology of the NLDH/PVDF nanocomposite membrane were efficiently improved by introducing 1 wt.% of PVP29000 to the matrix of the nanocomposite membrane. Furthermore, in the presence of PVP29000 as optimum additive, the NLDH/PVDF nanocomposite represented high pure water flux (702.2 L/m2 h), high water flux of BSA solution (119.3 L/m2 h) and good antifouling property (FRR of 73.41%).

    更新日期:2018-09-15
  • PREDICTIVE MODEL FOR THE DESIGN OF REACTIVE MICRO-SEPARATIONS
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-14
    Arantza Basauri, Jennifer Gomez-Pastora, Marcos Fallanza, Eugenio Bringas, Inmaculada Ortiz

    Solvent extraction at micro-scale has known increased interest in recent years. Consequently, numerous theoretical and experimental studies focused on diagnosis, detection and recovery of either biological substrates or base metals, isotopes and rare earths have been reported so far in the last few years.Within this context, the present work reports a thorough analysis of the coupling between the hydrodynamics, mass transfer and chemical reaction kinetics in multiphase micro-systems; the predictive mathematical model describes under non-steady state, fluid-wall interaction and interaction between the fluids in contact to finally predict the solute mass transport rate between the flowing liquid phases when a fully developed profile and a flat interface are not initially assumed unlike previously reported works. This approach allows tracking the interface along the complete micro device geometry and makes the model adaptive to the specific needs of each micro fluidic application. The analysis has been developed for a model system based on the mass transfer of Cr (VI) from an aqueous feed phase in a stratified 2-layer flow system in a Y-Y shape micro device. Two different scenarios have been considered: a) two homogeneous phases, where water is the receptor phase ii) an heterogeneous system where the solute moves from the feed solution to a receptor phase composed of Shellsol D-70 and Alamine 336 as the selective extractant. Model simulations accounting for the system reaction parameters already reported have been assessed against a set of experimental runs; the two systems under consideration provided data that satisfactorily fitted simulations with an error less than 10%, thus, validating model calculations. Thus, this rigorous and flexible model seeks to provide a useful tool for the design of micro separation processes by predicting the technical performance for numerous applications at micro scale.

    更新日期:2018-09-15
  • New Vacuum Distillation Technology for Separating and Recovering Valuable Metals from a High Value-added Waste
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-14
    Guozheng Zha, Chongfang Yang, Yunke Wang, Xinyu Guo, Wenlong Jiang, Bin Yang
    更新日期:2018-09-15
  • Economical approach to nitrate removal via membrane capacitive deionization
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-12
    Halil Ibrahim Uzun, Eyup Debik

    Groundwater is the most widely used water resource worldwide. In addition to natural underground pollutants, it is also affected by anthropogenic pollution sources. Highly soluble nitrate can easily leak into groundwater via precipitation. Nitrate has the potential to produce nitrosamines and thus can cause blue baby syndrome as well as several types of cancer, including that of the digestive system. Moreover, nitrates lead to eutrophication in bodies of water such as rivers and lakes. Therefore, organizations such as the World Health Organization (WHO) and the US Environmental Protection Agency (EPA) have limited the maximum acceptable nitrate concentration in drinking water to 10 mg/L. These adverse effects make it necessary to remove nitrates from water. The membrane capacitive deionization (MCDI) process can successfully remove nitrate. In this study, solutions with different concentrations of nitrate were treated via MCDI at different removal efficiencies, resulting in nitrate reductions below the limit values. Thus, the MCDI process proved to be an economical treatment approach, and during the treatment phase no significant effect of nitrate concentration levels was observed on the recovery efficiency. During the MCDI treatment, the electrodes accepted the SO42- and NO3- ions approximately equally, while Cl- removal rate was lower. Groundwater obtained from the Meric district of Edirne (Turkey) containing 233 mg/L nitrate was successfully purified via the MCDI process, with a nitrate removal efficiency of 98%. The energy expenditure calculated for the nitrate removal treatment of the groundwater was 0.4 kWh/m3.

    更新日期:2018-09-13
  • Effect of liquid surface tension on the filtration performance of coalescing filters
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Feng Chen, Zhongli Ji, Qiangqiang Qi
    更新日期:2018-09-11
  • Hydrothermal acid hydrolysis for highly efficient separation of lignin and xylose from pre-hydrolysis liquor of kraft pulping process
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Xue Chen, Xuefei Cao, Shaoni Sun, Tongqi Yuan, Shuangfei Wang, Quentin Shi, Runcang Sun
    更新日期:2018-09-11
  • Novel extractant (2,4-dimethylheptyl)(2,4,4’-trimethylpentyl)phosphinic acid (USTB-2) for rare earths extraction and separation from chloride media
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Junlian Wang, Xinyu Liu, Jiashuai Fu, Meiying Xie, Guoyong Huang, Huajun Wang

    Scientists have always been seeking more efficient extractants for rare earths extraction and separation, especially for heavy rare earths. In this paper, a novel extractant (2,4-dimethylheptyl)(2,4,4’-trimethylpentyl)phosphinic acid (USTB-2) was synthesized. The structures of the intermediate and USTB-2 were characterized by 31P NMR, 1H NMR, FT-IR and ESI-MS. Its pKa was 5.62. Its extraction ability was between Cyanex 272 and P507. Its extraction mechanism was cation exchange. Its extraction capacity was larger than that of Cyanex 272 and lower than that of P507. Its solubility in 3 mol/L HCl and deionized water was 11.2 mg/L and 19.0 mg/L, respectively. The Lu(III) loaded in USTB-2 solution can be easily stripped by HCl, HNO3 and H2SO4. It has good separation performance for heavy rare earths. Its average separation factor (β¯) for adjacent heavy REs from Gd to Lu was 2.18. For some heavy RE couples like Er/Ho, Yb/Tm and Lu/Yb (especially for Lu/Yb), USTB-2 possesses even better separation performance than Cyanex 272. Its extraction efficiency for nonferrous metal ions was in the order Al > Gd > Zn > Nd > La > Co > Cu. The separation factors of Al/Gd, Gd/Zn, Zn/Nd, La/Co by USTB-2 were 2.67, 5.39, 3.35 and 26.67, respectively.

    更新日期:2018-09-11
  • Azo dye adsorption on anthracite: a view of thermodynamics, kinetics and cosmotropic effects
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Nathalia Ribeiro de Mattos, Cassiano Rodrigues de Oliveira, Luis Gustavo Brogliato Camargo, Raissa Samira Rocha da Silva, Rodrigo Lassarote Lavall

    The present paper presents anthracite – a low cost and naturally abundant coal – as a potential adsorbent of the azo dye Acid Yellow 42, evaluating parameters such as dye concentration, temperature and ionic strength. A thermodynamic and kinetic approach was also described. Interactions between the adsorbate and anthracite were described by isothermal titration as well. Anthracite was characterized by TGA / DTA, FT-IR, X-ray, TEM / EDS. The adsorption system anthracite-dye reached equilibrium in less than 10 min at room temperature, with a maximum adsorption capacity as high as 47 mg g-1. A multi-layer pattern is observed according to the Freundlich adsorption model and the adsorption kinetics is best explained by the pseudo-second-order model. A chemisorption phenomenon drives the initial process, followed by a multi-layer physisorption phenomenon between dye molecules, with a prevalence of electrostatic interactions. The adsorption of acid yellow 42 onto anthracite is a spontaneous (ΔadsGo = -11.68 kJ mol-1) and endothermic (ΔadsH° = 58.59 kJ mol-1) process, suggesting that the driving force to promote adsorption is the increase of the degree of freedom in the interface anthracite/solution (ΔadsS° = 70.26 kJ mol-1). The amount of AY immobilized at the surface of anthracite increased with the temperature rising, evidencing an endothermic process. Cations and anions influence the adsorption process, not obeying and following Hofmeister series, respectively. Ionic charge lead to increase Zeta potential. Therefore, anthracite highlights as a potential adsorbent material for azo dyes compared with other natural materials and some activated carbons.

    更新日期:2018-09-11
  • Application of direct contact membrane distillation for textile wastewater treatment and fouling study
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    M. Laqbaqbi, M.C. García-Payo, M. Khayet, J. El Kharraz, M. Chaouch
    更新日期:2018-09-11
  • Evaluation of the Potential Application of Cactus (Opuntia ficus-indica) as a Bio-coagulant for Pre-treatment of Oil Sands Process-Affected Water
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Manisha Choudhary, Madhumita B. Ray, Sudarsan Neogi

    Environmentally benign natural agents in the treatment of water are increasingly gaining interest due to their cost effectiveness, low toxicity and inherently renewable characteristics. In this context the aqueous mucilage of Opuntia ficus-indica (OFI), a species of cactus, was utilized as a bio-coagulant for pre-treatment of OSPW (Oil sands process-affected water) for the first time. Coagulation/ flocculation tests were performed both on model turbid water and OSPW to explore the performance of extracted bio-coagulant on different types of water with varying turbidity. Effect of different operating parameters such as initial turbidity, pH, different salts, storage time and dosages was studied. The bio-coagulant performed extremely well with 98% turbidity removal from OSPW at initial pH of 7 and 8 using 1500 mg/l within 60 min. The active coagulant compound in mucilage of OFI was found to be a combination of pectic polysaccharide, non-polysaccharide and the natural electrolytes especially divalent cations such as Ca+2 and Mg+2. Formation of exceptionally thread like large flocs reveals the possibility that mechanism of coagulation by OFI is adsorption facilitated by inter-particle bridging. A comparative study between bio-coagulant and alum was also conducted and it was found that bio-coagulant resulted a compact sludge with less volume compared to alum.

    更新日期:2018-09-11
  • 更新日期:2018-09-11
  • Activated carbon adsorption of gold from cyanide-starved glycine solutions containing copper. Part 2: Kinetics
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    P.J. Tauetsile, E.A. Oraby, J.J. Eksteen

    The downstream processing of leachates arising from the dissolution of copper bearing gold ores in cyanide-starved alkaline glycine solutions is imperative for the successful implementation of the new leach system at industry level. This study investigates the behaviour of gold adsorption onto activated carbon in the presence of copper from cyanide-starved glycine solutions. The adsorption behaviour was kinetically investigated using the Fleming k,n model. The model had a high consistency with experimental data (up to 6 hours) for both gold and copper as evidenced by the regression coefficient (R2) values which were close to 1. The effects of important parameters including glycine concentration, solution pH, cyanide concentration, initial gold concentration, adsorbent concentration and ionic strength of the solution were studied. The results showed that, except for initial gold and carbon concentrations, a variation of these major factors had a pronounced effect on copper adsorption and slightly affected the gold adsorption, both in terms of adsorption rate and overall recovery. It was also seen that the active carbon had a high adsorption tendency towards gold over copper. The gold and copper extraction from a cyanide-glycine solution containing 2 mg/L gold, 300 mg/L copper, pH 11, 5 g/L glycine, Cu:CN of 1:1 (123 mg/L CN) and 8 g/L carbon using lime as a pH modifier reached 99.0% and 52.8% respectively. Most copper and gold was recovered in the first 6 hours. The corresponding initial adsorption rates are 1263.8 h-1 for gold and 19.0 h-1 for copper.

    更新日期:2018-09-11
  • Identification and role of Opuntia ficus indica constituents in the flocculation mechanism of colloidal solutions
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Omar Bouaouine, Isabelle Bourven, Fouad Khalil, Philippe Bressollier, Michel Baudu
    更新日期:2018-09-11
  • Resource recovery of critically-rare metals by hydrometallurgical recycling of spent lithium ion batteries
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Rabia Sattar, Sadia Ilyas, Haq Nawaz Bhatti, Abdul Ghaffar

    The increasing demand for critical metals and mounting pressure on the environmental impact of solid waste disposal have widely attracted the recycling of spent lithium ion batteries (LIBs). Although the hydrometallurgical recycling of LiCoO2 cathode materials from spent LIBs has been commonly investigated, the studies on LiNixCoyMnzO2 type cathode materials are infrequent. Hence, the present work is focused on sulfuric acid leaching of LiNixCoyMnzO2 cathode material for resource recovery of all the critical and rare metals from spent LIBs. The process parameters viz., pulp density, acid concentration, the dosage of reducing agent (i.e., H2O2), time, and temperature have been optimized for leaching of cathode powder (of weight composition: 7.6% lithium, 20.48% cobalt, 19.47% manganese, and 19.35% nickel). The maximum 92% lithium and nickel, 68% cobalt, and 34.8% manganese could be leached while leaching a 5% pulp density in 3.0 M H2SO4 without H2O2 at 90 °C. Leaching efficiencies of metals were found to be increased within 30 min and reaching to >98% by adding 4 vol.% H2O2 even at a lower temperature, 50 °C. Thereafter selective precipitations of manganese and nickel were carried out from leach liquor using KMnO4 and C4H8N2O2 as suitable precipitants, respectively. Subsequently, a 2-stage solvent extraction using 0.64 M Cyanex 272 (50% saponified) at equilibrium pH 5.0 and O:A of 1:1 was employed for recovery of a highly pure solution of CoSO4. Finally, lithium could be precipitated at Li+:Na2CO3 of 1.2:1.0 and a process flow-sheet has been proposed for the recycling of spent LIBs.

    更新日期:2018-09-11
  • CFD Simulations of Fiber-Fiber Interactions in a Hollow Fiber Membrane Bundle: Fiber Distance and Position Matters
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-10
    Chunyan Ma, Yanbiao Liu, Fang Li, Chensi Shen, Manhong Huang, Zhiwei Wang, Chun Cao, Qizhe Zhou, Yingzi Sheng, Wolfgang Sand
    更新日期:2018-09-11
  • Selective fractionation of sugar alcohols using ionic liquids
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-10
    L. Ruiz-Aceituno, C. Carrero-Carralero, L. Ramos, M.L. Sanz

    Sugar alcohols, such as xylitol, sorbitol and inositols, are added-value carbohydrates with relevant bioactive and technological properties. These features make their extraction from natural sources of great interest both from the scientific and industrial points of view. However, due to the similarity of the chemical structures of the different carbohydrates and the complexity of the extracted mixtures, the subsequent isolation of these sugar alcohols from other coextracted low molecular weight carbohydrates (LMWC) is still considered a challenging task.In this article, the solubility of linear sugar alcohols and inositols in selected ionic liquids (ILs), i.e., 1-hexyl-3-methylimidazolium chloride ([HMIM][Cl]), 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]), 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) and 1,3-dimethylimidazolium dimethylphosphate ([MMIM][Me2PO4]), has been investigated. The experimental results demonstrated widely divergent solubilities (in the 1.7 – 84.7 %, w/w, range) for the several targeted carbohydrates in the different ILs evaluated, with [EMIM][OAc] and [MMIM][Me2PO4] providing the highest solubility values. These ILs gave also the best results when applied to the selective fractionation of sugar alcohols from other LMWC in 1:1 (w/w) binary mixture (yields in the 60 – 98 % range). These results show ILs as promising non-volatile and environmental friendly solvents for this type of fractionation process and suggest the interest of further investigation in this particular application field.

    更新日期:2018-09-11
  • 更新日期:2018-09-11
  • Design, optimization and control of extractive distillation for the separation of isopropanol-water using ionic liquids
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-10
    Shoutao Ma, Xianyong Shang, Minyan Zhu, Jinfang Li, Lanyi Sun
    更新日期:2018-09-11
  • Design and economic evaluation of energy-saving industrial distillation processes for separating close-boiling cyclohexanone-cyclohexanol mixture
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-10
    Hongdan Wang, Chengtian Cui, Hao Lyu, Jinsheng Sun

    In this study, several heat-integrated distillation processes are compared to separate the close-boiling cyclohexanone (CHON)-cyclohexanol (CHXA) for improving energy efficiency. A 4-column scheme, including two light ends columns in DRP (distillation with recycle process), a CHON column and a CHXA column, is introduced as the prototype scheme. To make improvement, light and heavy split DRP – are compared for energy optimization upon the prototype. The light split DRP turns out to be superior and thus used for subsequent steps. Four heat-integrated schemes including double-effect distillation (DED), heat pump assisted distillation (HPAD), DED plus HPAD (DEHP) and double HPAD (DHPAD) are sequentially suggested and evaluated based on total annualized cost (TAC). The results show TAC reductions from the prototype of 32.2%, 23.6%, 29.2% and 10.8% for DED, HPAD, DEHP and DHPAD, respectively. The DED scheme requires the lowest TAC due to the 48.4% operating cost and 8% capital cost saving, whereas the DEHP scheme has the lowest 56.3% operating cost reduction with 11.1% more capital investment. The line of thinking in this work will benefit in other close-boiling systems for higher energetic efficiency and economic profit.

    更新日期:2018-09-11
  • A new approach for characterization of hydrophobization mechanisms of surfactants on muscovite surface
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    Hao Jiang, Ya Gao, Sultan Ahmed Khoso, Wanying Ji, Yuehua Hu
    更新日期:2018-09-11
  • Activated carbon adsorption of gold from cyanide-starved glycine solutions containing copper. Part 1: Isotherms
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-11
    P.J. Tauetsile, E.A. Oraby, J.J. Eksteen

    Cyanide-starved alkaline glycine solutions have been shown to have distinct advantages in terms of lower reagent consumption and detoxification needs, or leach rate and recovery, over cyanide- only and glycine-only leach systems respectively for gold ores with nuisance copper. Activated carbon has been shown to be suitable for gold adsorption from alkaline glycine systems, and is well established for cyanide based systems. Activated carbon being an effective substrate for the adsorption of gold thus offers a possible downstream carbon-in-pulp (CIP) recovery route for alkaline glycine leach systems and hybrid systems in the presence of cyanide. Given the frequent occurrence of gold deposits with high levels of nuisance copper, the equilibrium loading of gold and copper onto activated carbon from cyanide-starved alkaline glycine solutions containing copper and gold has been studied. Adsorption efficiency was studied in terms of equilibrium loading isotherms. Results showed that while copper adsorption is more sporadic based on goodness of fit, gold adsorption is more consistent and clearly follows the Freundlich isotherm model (good linear correlation of log Q vs log C values). The adsorption isotherms were obtained using a gold concentration of 2 ppm. In the presence of copper, the equilibrium gold loading increases with increasing glycine and calcium ion concentrations, decreases with increasing cyanide concentration and is not affected by initial gold concentration. The cuprous cyanide and cupric glycinate complexes lowered gold loading through a competitive adsorption with the copper (I) cyanide complexes adsorbing more rapidly on the carbon than their glycinate counterparts. The equilibrium gold loading capacity in cyanide-starved glycine solutions containing 2ppm Au and 300ppm Cu, at pH 11 was found to be 9.95 kgAu/toncarbon in 24 h, which is almost four times higher than the gold loading capacity in a pure cyanide system (2.7 kgAu/toncarbon) under similar conditions. The study revealed that activated carbon was an effective adsorbent for removal gold from cyanide-glycine aqueous solutions.

    更新日期:2018-09-11
  • Fabrication and photoelectrochemical performance of Ag/AgBr sensitized TiO2 nanotube arrays for environmental and energy applications
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-10
    Qianqian Zhao, Qingyao Wang, Zhiyuan Liu, Longyu Qiu, Xiaoyu Tian, Shaohua Zhang, Shanmin Gao
    更新日期:2018-09-10
  • 更新日期:2018-09-07
  • Removal of some commercial pesticides from aqueous dispersions using as flocculant a thymine-containing chitosan derivative
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-06
    Luminita Ghimici, Ionel Adrian Dinu

    A novel thymine-containing chitosan derivative has been designed, synthesized, and used for the first time in this work for removal of some commercial pesticides from synthetic wastewater by coagulation/flocculation. The chitosan-thymine conjugate was characterized by 1H NMR and FT-IR spectroscopy, and its flocculation performance was evaluated by UV-Vis spectroscopy in comparison to non-modified chitosan. The commercial pesticides used in this investigation were Fastac 10 EC and Karate Zeon (with alpha-Cypermethrin and lambda- Cyhalothrin, respectively, as active pyrethroid ingredients), Novadim Progress (Dimethoate as active organophosphoric ingredient), and Bordeaux mixture. The experimental results demonstrate good removal efficiency for Karate Zeon (between 80-85%), a maximum of around 90% for Fastac 10EC and Novadim Progress, and more than 95% for the Bordeaux mixture, irrespective of the polycation structure. According to the zeta potential values recorded in the optimum dose interval, the flocculation of pyrethroid pesticides particles took place mainly by means of the charge neutralization mechanism (close to zero), whereas the flocculation of Novadim Progress and Bordeaux mixture particles has been achieved by the synergistic effect of charge neutralization and hydrogen bonding (Novadim Progress) or copper ion binding by the amine and thymine groups (Bordeaux Mixture) (negative values).

    更新日期:2018-09-07
  • Batch preparation of ammonium isopolymolybdate solution from ammonium molybdate solutions using bipolar membrane electrodialysis
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-07
    Guiqing Zhang, Qiang Wang, Wenjuan Guan, Li Zeng, Qinggang Li, Zuoying Cao, Liansheng Xiao, Qin Zhou

    The disadvantage of the traditional ammonium tetramolybdate (ATM) production process is a large consumption of nitric acid. Therefore a novel process for the generation of ammonium isopolymolybdate solution from ammonium molybdate solution using bipolar membrane electrodialysis (BMED) was developed and the batch experiment was carried out in this paper. The BMED process was studied to optimize various parameters such as initial base solution, final electrolytic pH value of salt solution, current density, initial NH4HCO3 concentration of base solution and Mo concentration in feed solution. The average current efficiency was 82%, the power consumption was 0.058 kWh/mol NH4+ or 0.887 kWh/mol Mo, and the recovery rate of Mo reached 99.4% under the optimal conditions of a current density of 500 A/m2 , an initial Mo concentration of 173 g/L in the salt compartment, an initial NH4HCO3 concentration 2.0 mol/L in the base compartment, an initial (NH4)2CO3 concentration of 1.0 mol/L in the electrode solution and 32 ± 0.5 °C and a final solution pH of 4.0 in the salt compartment .

    更新日期:2018-09-07
  • Preparation of SSZ-13 membranes with enhanced fluxes using asymmetric alumina supports for N2/CH4 and CO2/CH4 separations
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-07
    Shichao Song, Feng Gao, Yue Zhang, Xinping Li, Ming Zhou, Bin Wang, Rongfei Zhou
    更新日期:2018-09-07
  • Polarity reversal electrochemical process for water softening
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-06
    Huachang Jin, Yang Yu, Li Zhang, Runxin Yan, Xueming Chen

    Electrochemical precipitation has attracted widespread attention in the treatment of recirculating cooling water in recent years. In order to guarantee continuous water softening efficiency, periodic scale detachment of cathode is indispensable. Nevertheless, periodic mechanical scrapping, prevalent scale detachment technique currently, increases the interelectrode gap, resulting in the decline of water softening efficiency and the rise of energy consumption. In this paper, polarity reversal was applied in the electrochemical precipitation process for removing scale deposits. The results showed that scale deposits were removed effectively and high water softening efficiency were accomplished steadily. The precipitation rate obtained was 53.9-73.4 g/h/m2. The reactor still could remove hardness ions efficiently after the scale detachment by polarity reversal. The energy consumption maintained in the range of 17.3 to 23.6 kWh/kg CaCO3. The total hardness removal efficiency was 16.4-21.4 %. Repeated experimental results demonstrated that the electrochemical precipitation process adopting polarity reversal for scale detachment could operate steadily without any performance degradation detected. Cyclic voltammetric investigation showed good electrochemical stability of dimensionally stable anode (DSA) used. Accelerated life test indicated that it could keep active steadily in polarity reversal condition.

    更新日期:2018-09-06
  • Metal ions and organic dyes sorption applications of cellulose grafted with binary vinyl monomers
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-06
    Rajeev Kr. Sharma, Rajesh Kumar, Anirudh P. Singh

    Metal ions and dyes sorption applications of Cell-g-AASO3H-co-GMA were studied, herein. The adsorbent Cell-g-AASO3H-co-GMA was synthesized through grafting of 2-acrylamido-2-methylpropane sulfonic acid (AASO3H) and binary comonomer glycidyl methacrylate (GMA) using potassium persulfate (KPS) as free radical chemical initiator and N,N′-methylene bisacrylamide (NMBA) as cross-linker onto the cellulose extracted from agricultural waste rice husk. The graft copolymer was characterized for morphological, structural, compositional, crystalline and thermal properties through different characterization techniques like FTIR, FESEM, XRD, and TGA/DTA. The swelling behavior of the graft copolymer was evaluated at 2.2, 7.0 and 9.4 pH and compared with the pristine cellulose to explore their applications for the sorption of metal ions and dyes from their aqueous solutions. The adsorption parameters were elaborated for model cationic malachite green (MG) and crystal violet (CV) dyes, anionic congo red (CR) dye and Ni2+ and Cu2+ ions. The adsorption of dyes and metal ions was investigated as a function of contact time, temperature, pH and concentration. The mechanism of the adsorption and the interactions between adsorbent Cell-g-AASO3H-co-GMA and different adsorbates were studied using different kinetics and adsorption isotherms models. The adsorption data for dyes and metal ions fitted well with the pseudo-second-order rate equation and Langmuir adsorption isotherm. The maximum adsorption capacity of Cell-g-AASO3H-co-GMA, obtained from the Langmuir adsorption isotherm for MG, CV and CR dyes were 46.232, 53.533 and 20.942 mg.g-1, whereas for Cu2+ and Ni2+ ions it was78.247 and 69.061 mg.g-1 respectively.

    更新日期:2018-09-06
  • Nanopatterning commercial nanofiltration and reverse osmosis membranes
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-06
    Steven T. Weinman, Eric M. Fierce, Scott M. Husson
    更新日期:2018-09-06
  • Scale-up in froth flotation: A state-of-the-art review
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-05
    Diego Mesa, Pablo R. Brito-Parada

    Froth flotation has been one of the most important and widely used methods to concentrate minerals since its introduction over a hundred years ago. Over the last few decades, in order to process more mineral while reducing capital costs, flotation equipment has become exponentially larger. The increase in tank volume, however, has brought new challenges in the operation and design of industrial flotation tanks. This review analyses the literature on flotation tank scale-up for the first time, contrasting several techniques and approaches used in both historical and state-of-the-art research. The study of flotation scale-up is crucial for the optimisation of industrial plant performance and the maximisation of laboratory-scale research impact. While important advances in our understanding of flotation have been achieved, large flotation tank design and scale-up has, to a large extent, remained in-house know-how of manufacturing companies. This review of the literature relevant to flotation tank scale-up has resulted in a new classification, dividing the scale-up literature into two main areas of study, namely “Kinetic scale-up” and “Machine design scale-up”. This review indicates that current scale-up rules governing the design of flotation tanks focus mainly on pulp zone kinetic parameters and neglect the effects on the froth zone, despite the importance of froth stability and mobility in determining flotation performance. Froth stability and mobility are closely linked to the distance the froth needs to travel, which increases with tank diameter. Although including internal elements, such as launders and crowders, has been the industrial solution for enhancing froth transport and recovery in larger tanks, the design and scale-up of these elements have not been thoroughly studied. Gaps in our knowledge of flotation are discussed in the context of addressing the scale-up problem, considering froth transport and froth stability. Addressing these gaps will pave the way for the design and operation of large flotation tanks of enhanced performance.

    更新日期:2018-09-05
  • Liquid-Liquid Extraction of Phenolic Compounds in Systems Based on Acetonitrile + Water + Polyvinylpyrrolidone at 298.15 K
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-05
    Bruno Sales Oliveira, Camila Maria de Souza D'Anzicourt, Cleide Mara Faria Soares, Ranyere Lucena de Souza, Álvaro Silva Lima

    Liquid-liquid equilibrium data for systems based on acetonitrile + polyvinylpyrrolidone (PVP) (10000, 29000 and 40000 g.mol-1) + water were experimentally measured at 298.15 ± 1.00 K and 0.1 ± 0.01MPa. Merchuck’s empirical equation was correlated with experimental binodal data, and the tie-lines and critical points (PCs) to complete the phase diagrams were determined. In both phases, the content of acetonitrile is high (> 50 wt%), as the top-phase is rich in water while the bottom phase is rich in PVP. The systems were used in the partitioning of three phenolic compounds (here used as standard biomolecules). Cyanidin-3-O-glucoside chloride migrated preferentially to the top phase while gallic acid and quercetin migrated to the PVP-rich phase. The system formed by acetonitrile (ACN) (62.05 wt%) + PVP-10000 (12.05 wt%) + H2O (25.90 wt%) was more selective for the separation of cyanidin-3-O-glucoside chloride from gallic acid (SCYA/AGA = 65.41) and quercetin (SCYA/QUE = 42.77).

    更新日期:2018-09-05
  • A novel Ag2O/g-C3N4 p-n heterojunction photocatalysts with enhanced visible and near-infrared light activity
    Sep. Purif. Technol. (IF 3.927) Pub Date : 2018-09-05
    Shuhui Liang, Dafeng Zhang, Xipeng Pu, Xintong Yao, Ruoting Han, Jie Yin, Xiaozhen Ren

    A series of p-n junction Ag2O/g-C3N4 photocatalysts with different Ag2O contents were successfully prepared though a facile chemical precipitation method at room temperature. The as-synthesized samples were characterized in detail by XRD, EDS, XPS, SEM and DRS. The experimental results demonstrated that Ag2O nanoparticles were well distributed on the surface of g-C3N4 and the heterostructure of Ag2O/g-C3N4 was constructed. As-synthesized Ag2O/g-C3N4 heterojunction photocatalysts exhibited an excellent wide-spectrum response ranging from ultraviolet (UV) to near-infrared (NIR), indicating its potential for effective utilization of solar light energy. The as-prepared Ag2O/g-C3N4 shows excellent photocatalytic properties for the degradation of Rhodamine B (RhB), phenol, imidacloprid, methylene blue (MB) and methyl orange (MO) under visible and NIR light irradiation. The degradation rate constants of Ag2O/g-C3N4 (8:1) for RhB were 0.05188 and 0.01368 min-1 under visible and NIR irradiation, which are about 26 and 343 times higher than that of pure g-C3N4, respectively, and are even better than that of Ag2O under the same conditions. The enhanced photochemical activities are attributed to the formation of the heterostructure between Ag2O and g-C3N4, and efficient charge separation efficiency. Finally, a possible photocatalytic mechanism was proposed for this photocatalyst.

    更新日期:2018-09-05
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
化学 • 材料 期刊列表