大孔吸附树脂法柚皮果胶脱色工艺研究

比较了AB-8、S-8、X-5、聚酰胺、NKA-Ⅱ、NPD-600等6种大孔吸附树脂对柚皮果胶的脱色效果.在静态吸附试验研究的基础上,筛选出效果较好的树脂进行动态试验研究.实验表明:AB-8型大孔吸附树脂对柚皮果胶提取液具有较好的吸附脱色效果和较低的果胶损失率,该树脂对柚皮果胶脱色的适宜工艺参数为:室温(约20℃),流速3BV/h,溶液处理量为5BV,上柱液pH值为4～6.此工艺对果胶提取液中色素的吸附率约80%.树脂吸附后可用70%乙醇进行洗涤再生,果胶提取液脱色后经喷雾干燥所得的果胶成品质量符合QB2484-2000标准.     

ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore, the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.     

大孔吸附树脂提取穿心莲总内酯的研究

研究了大孔吸附树脂提取和纯化穿心莲总内酯的方法，采用HPLC法测定了穿心莲内酯的含量；考查了乙醇浓度对浸提效果的影响，并经动态吸附筛选了4种树脂；最后确定以ADS－7作为提取分离穿心莲总内酯的树脂，此树脂吸附量较高，脱附容量且能与杂质分离，有利于得到质量较好的穿心莲总内酯产品。     

Adsorption of Gases, Vapors and Liquids by Microporous Adsorbents

Adsorption of Xe, Kr, Ar, N₂, O₂, H₂ CH₄, CO₂, He, and freons by PAU-10 and ACC microporous carbon adsorbents as well as by A and X zeolites was investigated over a wide range of pressures (0.1 Pa – 20 MPa) and temperatures (77, 120–600 K). The amount of gases, vapors and liquids adsorbed by microporous adsorbents increases steadily with increasing pressure and does not change dramatically if phase transitions occur in the adsorptive. Isosteres of adsorption constructed as a curve of ln P against f(1/T)_a retain a linear form over a wide range of pressures and temperatures. The slope of isosteres does not vary on going through the critical temperature of the gaseous phase. At high pressures, due to non-ideality of the gaseous phase and non-inert behavior of the adsorbent the differential molar heat of adsorption is dependent on temperature. At high fillings of micropores the differential molar isosteric heat capacities of adsorption systems show maxima that indicate the occurrence of structural rearrangements in the adsorbate.     

Recent advances and spectroscopic perspectives in fluoride removal

With the constant rising demand for pure water to meet the needs of the growing population particularly in developing countries, fluoride remediation from drinking water has emerged as an increasingly important matter of public concern. In the past decade, significant efforts and advances have been made for developing efficient adsorbents for fluoride removal from water. This review summarizes recent advances (2012–2016) in defluoridation techniques and highlights the challenges and opportunities for future research in the important field of fluoride removal. The spectroscopic techniques, used to develop adsorbents/adsorption mechanism, discussed in this review are X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma mass spectrometry, atomic absorption spectrometry, inductive coupled plasma-optical emission spectroscopy, and X-ray photoelectron spectroscopy. The defluoridation techniques have been discussed in four categories: precipitation, membrane, ion-exchange, and adsorption techniques. Then recent research on fluoride removal using various adsorbents with their spectroscopic studies are summarized and discussed with regard to their synthetic chemistry, properties, and applications. The advantages and disadvantages of defluoridation techniques and adsorbents have been presented. Finally, the future needs and perspectives of fluoride removal are addressed.     

Preparative enrichment and separation of astragalosides from Radix Astragali extracts using macroporous resins

The enrichment and separation of astragalosides I–IV (AGs I–IV) were studied on eight macroporous resins in the present study. SA‐3 resin offered the best adsorption and desorption capacities for AGs I–IV than other resins. The models of adsorption kinetics were investigated in order to elucidate the mechanism of adsorption. The pseudo‐second‐order model was the better choice than the pseudo‐first‐order model to describe the adsorption behavior of AGs I–IV onto SA‐3 resin. The equilibrium experimental data were well fitted to Langmuir and Freundlich isotherms. SA‐3 resin adsorption chromatography tests were carried out to optimize the separation process of AGs I–IV from Radix Astragali extracts. With the optimum parameters for adsorption and desorption, the contents of AGs I–IV were 8.78‐, 11.60‐, 10.52‐ and 11.28‐fold increased with the recovery yields being 65.88, 90.92, 84.25 and 94.17%, respectively. The preparative enrichment and separation of AGs I–IV from Radix Astragali extracts can be easily and effectively achieved by SA‐3 resin adsorption chromatography. The developed methodology can also be referenced for the separation of other active constituents from herbal materials and manufacture of Radix Astragali products.     

Efficiency of a novel nitrogen-doped Fe3O4 impregnated biochar (N/Fe3O4@BC) for arsenic (III and V) removal from aqueous solution: Insight into mechanistic understanding and reusability potential

Worldwide, arsenic contamination has become a matter of extreme importance owing to its potential toxic, carcinogenic and mutagenic impact on human health and the environment. The magnetite-loaded biochar has received increasing attention for the removal of arsenic (As) in contaminated water and soil. The present study reports a facile synthesis, characterization and adsorption characteristics of a novel magnetite impregnated nitrogen-doped hybrid biochar (N/Fe₃O₄@BC) for efficient arsenate, As(V) and arsenite, As(III) removal from aqueous environment. The as-synthesized material (N/Fe₃O₄@BC) characterization via XRD, BET, FTIR, SEM/EDS clearly revealed magnetite (Fe₃O₄) impregnation onto biochar matrix. Furthermore, the adsorbent (N/Fe₃O₄@BC) selectivity results showed that such a combination plays an important role in targeted molecule removal from aqueous environments and compensates for the reduced surface area. The maximum monolayer adsorption (Q_max) of developed adsorbent (N/Fe₃O₄@BC) (18.15 mg/g and 9.87 mg/g) was significantly higher than that of pristine biochar (BC) (9.89 & 8.12 mg/g) and magnetite nano-particles (MNPs) [7.38 & 8.56 mg/g] for both As(III) and As(V), respectively. Isotherm and kinetic data were well fitted by Langmuir (R² = 0.993) and Pseudo first order model (R² = 0.992) thereby indicating physico-chemical sorption as a rate-limiting step. The co-anions (PO₄^3-) effect was more significant for both As(III) and As (V) removal owing to similar outer electronic structure. Mechanistic insights (pH and FTIR spectra) further demonstrated the remarkable contribution of surface groups (OH^–, –NH₂ and –COOH), electrostatic attraction (via H- bonds), surface complexation and ion exchange followed by external mass transfer diffusion and As(III) oxidation into As(V) by (N/Fe₃O₄@BC) reactive oxygen species. Moreover, successful desorption was achieved at varying rates up to 7th regeneration cycle thereby showing (N/Fe₃O₄@BC) potential practical application. Thus, this work provides a novel insight for the fabrication of novel magnetic biochar for As removal from contaminated water in natural, engineering and environmental settings.     

On-line coupling of counter-current chromatography and macroporous resin chromatography for continuous isolation of arctiin from the fruit of Arctium lappa L.

In this work, we have developed a novel hybrid two-dimensional counter-current chromatography and liquid chromatography (2D CCC × LC) system for the continuous purification of arctiin from crude extract of Arctium lappa. The first dimensional CCC column has been designed to fractionalize crude complex extract into pure arctiin effluent using a one-component organic/salt-containing system, and the second dimensional LC column has been packed with macroporous resin for on-line adsorption, desalination and desorption of arctiin which was effluent purified from the first CCC dimension. Thus, the crude arctiin mixture has been purified efficiently and conveniently by on-line CCC × LC in spite of the use of a salt-containing solvent system in CCC separation. As a result, high purity (more than 97%) of arctiin has been isolated by repeated injections both using the ethyl acetate–8% sodium chloride aqueous solution and butanol–1% sodium chloride aqueous solution. By contrast with the traditional CCC processes using multi-component organic/aqueous solvent systems, the present on-line CCC × LC process only used a one-component organic solvent and thus the solvent is easier to recover and regenerate. All of used solvents such as ethyl acetate, n-butanol and NaCl aqueous solution are low toxicity and environment-friendly. Moreover, the lower phase of salt-containing aqueous solution used as mobile phase, only contained minor organic solvent, which will save much organic solvent in continuous separation. In summary, our results indicated that the on-line hybrid 2D CCC × LC system using one-component organic/salt-containing aqueous solution is very promising and powerful tool for high-throughput purification of arctiin from fruits of A. lappa.     

不同树脂对瓜果腐霉代谢产物中除草活性成分的吸附分析

利用HPD400、HPD500、HPD600、HPD700、HPD850、ADS-17、D101、DM130大孔吸附树脂对瓜果腐霉培养滤液中除草活性成分的吸附情况进行了研究,通过对树脂吸附后的流出液和洗脱液的浓缩物进行HPLC检测分析,确定了其除草活性成分。实验发现,在所选择的8种树脂中以HPD500、HPD850、HPD600、ADS-17对除草活性成分的吸附能力最强,其中以HPD500和HPD600树脂的10%的乙醇洗脱液中除草活性成分含量最高。综合结果表明,以HPD500树脂作为吸附瓜果腐霉培养滤液中除草活性成分的适宜树脂。研究发现,HPD500树脂对除草活性成分吸附和解吸附的最佳条件是:吸附最适温度为20℃,树脂吸附饱和度为33.75mL/g,较适宜吸附流速为2BV/h,较适宜脱附流速为1BV/h,洗脱剂浓度为10%乙醇,洗脱剂用量为2.5BV。     

Preparation of thin layer materials with macroporous microstructure for SOFC applications

A facile and versatile method using polymethyl methacrylate (PMMA) microspheres as pore formers has been developed to prepare thin layer oxide materials with controlled macroporous microstructure. Several mixed oxides with fluorite and perovskite-type structures, i.e. doped zirconia, ceria, ferrites, manganites, and NiO-YSZ composites have been prepared and characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption and mercury porosimetry. The synthesised materials are nanocrystalline and present a homogeneous pore distribution and relatively high specific surface area, which makes them interesting for SOFC and catalysis applications in the intermediate temperature range.