累托石吸附分离水中金霉素(英文)

The removal of antibiotics from water by clay minerals has become the focus of research due to their strong adsorptive ability. In this study, adsorption of chlortetracycline (CTC) onto rectories was conducted and the effects of time, concentration, temperature and pH were investigated. Experimental results showed that adsorption equilibrium was reached in 8 h. Based on the Langmuir model, the maximum adsorption capacity of CTC on rectories was 177.7 mg·g 1 at room temperature. By the study on adsorption dynamics, it is found that the kinetic date fit the pseudo-second-order model well. The adsorption of CTC by rectories is endothermic and the free energy is in the range of 10 to 30 kJ·mol 1 . The pH value of solution has significant effects on adsorption and the optimal pH is at acidity (pH 2-6). At concentration of 2500 mg·L 1 , the intercalated CTC produces an interlayer space with a height of 1.38 nm, which is 1.12 nm in raw rectories, suggesting that the adsorption occurs between layers of rectories.     

Removal of Cd（II） by Nanometer AIO（OH） Loaded on Fiberglass with Activated Carbon Fiber Felt as Carrier

A new nanometer material, nanometer AlO（OH） loaded on the fiberglass with activated carbon fibers felt（ACF） as the carrier, was prepared by hydrolytic reaction for the removal of Cd（II） from aqueous solution using column adsorption experiment. As was confirmed by XRD determination, the hydrolysis production loaded on fiberglass was similar to the orthorhombic phase AlO（OH）. SEM images showed that AlO（OH） particles were in the form of small aggregated clusters. The Thomas model was applied for estimating the kinetic parameters and the saturated adsorption ability of Cd（II） adsorption on the new adsorbent. The results showed that the maximum adsorption capacity of Cd（II） was 128.50 mg·g^-1 and 117.86 mg·g^-1 for the adsorbent mass of 0.3289 g and the adsorbent mass of 0.2867 g, respectively. The elution experiment result indicated that the adsorbed Cd ions was easily desorbed from the material with 0.1 mol·L^-1 HCl solution. Adsorption-desorption cycles showed the feasibility of repealed uses of the composited material. The adsorption capacities were influenced by pH and the initial Cd（II） concentration. The amount adsorbed was greatest at pH 6.5 and the initial Cd（II） concentration of 0.07 mg·L^-1, respectively. Nanometer AlO（OH） played a major role in the adsorption process, whereas the fiberglass and ACF were assistants in the process of removing Cd（II）. In addition, the adsorption capacities for Cd（II） were obviously reduced from 128.50 mg·L^-1 to 64.28 mg·L^-1 when Pb ions were present because Pb ions took up more adsorption sites.     

零价铁对活性黑K-BR脱色动力学

Decoloration of simulated wastewater containing dye reactive black K-BR by zero-valent iron was investigated. The results showed that decoloration efficiency increased with decreasing pH or initial dye concentration, and increased with increasing iron loading. The reaction followed first-order kinetics initially but deviated from first - order behavior with increasing time. Considering the decrease of active surface area of zero-valent iron with time, decoloration kinetics was expressed as ln(c/co)= K[1-exp(-kdt)]/kd. It indicated that kd was independent of iron loading and pH, and decreased with increasing initialdye concentration. K was proportional to iron loading, and decreased with increasing pH or initial dye concentration.     

A novel green inhibitor for C-steel corrosion in 2.0 mol·L~(-1) hydrochloric acid solution

The corrosion inhibition characteristics of aqueous extract of seeds of Melia azedarach L.(MA) have been studied as eco-friendly green inhibitor for corrosion control of C-steel in 2 mol·L~(-1) HCl solution by gravimetric and electrochemical methods. The results depict that, the extract inhibits efficiently the corrosion of carbon steel in hydrochloric acid. The efficiency of extract is increased with increasing the extract concentration but independent on the studied temperature. The adsorption of the extract components onto the steel surface was found to be spontaneous, and follows Langmuir adsorption isotherm. The surface morphology of C-steel, in the absence and presence of MA extract in 2.0 mol·L~(-1) hydrochloric acid solution, was studied using scanning electron microscopy(SEM).     

Kinetic and thermodynamic studies of acid scarlet 3R adsorption onto low-cost adsorbent developed from sludge and straw简

A low-cost adsorbent was prepared from sludge and straw by pyrolysis in a dried state with the surface area of the adsorbent of 829.49 ma. g-l, micropore volume of 0.176 cm2·g-1 and average pore radius of 5.0 nm. The kinetic, equilibrium isotherm and thermodynamic characteristics of trisodium 1-（1-naphthylazo）-2-hydroxynaphthalene- 4＇,6,8-trisulphonate （acid scarlet 3R） onto the adsorbent from sludge and straw were investigated. The results indicated that the pseudo second order adsorption was the predominant adsorption mechanism of acid scarlet 3R. Thus, the adsorption phenomenon was suggested as a chemical process. The adsorption data were fitted better with Langmuir model than Freundlich model, indicating that the adsorption of acid scarlet 3R belonged to the monolayer adsorption and mainly occurred in micropores.     

Ghezeljeh nanoclay as a new natural adsorbent for the removal of copper and mercury ions:Equilibrium,kinetics and thermodynamics studies

Heavy metal determination was carried out by applying the solid phase extraction (SPE) method in batch mode followed by atomic absorption spectroscopy (AAS) and inductively coupled plasma atomic emission spectrosco-py (ICP-AES) from aqueous solutions using Ghezeljeh montmoril onite nanoclay as a new natural adsorbent. The Ghezeljeh clay is characterized by using Fourier Transform Infrared (FT-IR) Spectroscopy, Scanning Electron Mi-croscopy–Energy Dispersive Spectrometry (SEM–EDS) and X-ray Diffractometry (XRD) and X-ray Fluorescence (XRF). The results of XRD and FT-IR of nanoclay confirm that montmoril onite is the dominant mineral phase. Based on SEM images of Ghezeljeh clay, it can be seen that the distance between the plates is Nano. The effects of varying parameters such as initial concentration of metal ions, pH and type of buffer solutions, amount of ad-sorbent, contact time, and temperature on the adsorption process were examined. The effect of various interfer-ing ions was studied. The adsorption data correlated with Freundlich, Langmuir, Dubinin–Radushkevich (D–R), and Temkin isotherms. The Langmuir and Freundlich isotherms showed the best fit to the equilibrium data for Hg(I ), but the equilibrium nature of Cu(II) adsorption has been described by the Langmuir isotherm. The kinetic data were described with pseudo-first-order, pseudo-second-order and double-exponential models. The adsorp-tion process follows a pseudo-second-order reaction scheme. Calculation ofΔG0,ΔH0 andΔS0 showed that the nature of Hg(II) ion sorption onto the Ghezeljeh nanoclay was endothermic and was favored at higher temper-ature, and the nature of Cu(II) ion sorption was exothermic and was favored at lower temperature.     

Pt、Rh及Pt-Rh合金电极上氢的吸附

The hydrogen adsorption on Pt-Rh alloys in sulfuric acid aqueous solutions was studied by the method of cathode pulses. Hydrogen adsorption on the electrode with all ratio of alloy components (ωRh = 0-100%) is well described by the Temkin logarithmic isotherm. The surface coverage by adsorbed hydrogen at the same potential is decreased with increasing content of rhodium in the system. A linear dependence of adsorption peak potential on the alloy compositions in the case of weakly bonded adsorbed hydrogen is established. Hydrogen adsorption heat as a function of surface coverage for Pt-Rh-electrodes was obtained. The shape of the current-potential curve and position of the weakly bonded hydrogen adsorption on the potential scale are all related to alloy compositions, thus can serve as the basis for the determination surface composition of allovs.     

活性白土对模拟油脂中β-胡萝卜素和叶绿素的吸附动力学研究

The textural properties of acid-activated bentonite (AAB), which were prepared using four different concentrations of sulfuric acid, were analyzed by adsorption-desorption isotherm of nitrogen using an automated specific surface area and porosity analyzer. The total pore volume, specific surface area and average pore diameter of these four kinds of AAB show a regular changing trend, increasing first and then decreasing, the optimum of which can be achieved at a sulfuric acid concentration of 25% (sample A25). The kinetic analysis of the adsorption ofβ-carotene and chlorophyll in model oil solutions, namely, xylene and edible oil solution, has been investigated by using AAB. Experimental results indicated that the adsorption data fit the pseudo-second-order model well. The whole adsorption process of the two pigments on AAB was divided basically into two parts the initial adsorption of pigments was rapid in the first 10 min, followed by a slower adsorption process till equilibrium was attained at 60 min. In addition, the amount and rate of adsorption on A25 increase synchronously with the initial pigment concen-tration and temperature. The results showed that the adsorption kinetics behavior of AAB with respect to the pig- ments is not influence by the xylene and edible oil solution.     

Monte Carlo模拟对称型三嵌段共聚高分子的吸附

The adsorption behavior of symmetric triblock copolymers, Am/2BnAm/2, from a nonselective solvent at solid-liquid interface has been studied by Monte Carlo simulations on a simple lattice model. Either segment A or segment B is attractive, while the other is non-attractive to the surface. Influences of the adsorption energy,bulk concentration, chain composition and chain length on the microstructure of adsorbed layers are presented.The results show that the total surface coverage and the adsorption amount increases monotonically as the bulk concentration increases. The larger the adsorption energy and the higher the fraction of adsorbing segments, the higher the total surface coverage is exhibited. The product of surface coverage and the proportion of non-attractive segments are nearly independent of the chain length, and the logarithm of the adsorption amount is a linear function of the reciprocal of the reduced temperature. When the adsorption energy is larger, the adsorption amount exhibits a maximum as the fraction of adsorbing segment increases. The adsorption isotherms of copolymers with different length of non-attractive segments can be mapped onto a single curve under given adsorption energy. The adsorption layer thickness decreases as the adsorption energy and the fraction of adsorbing segments increases, but it increhses as the length of non-attractive segments increases. The tails mainly govern the adsorption layer thickness.     

Insights into membrane fouling implicated by physical adsorption of soluble microbial products onto D3520 resin

Membrane fouling is a major problem in membrane bioreactors(MBRs). In this study, membrane fouling caused by membrane rejection and adsorption was study. Filtration tests indicated that membrane rejected SMP, causing membrane pore blockage and then forming a gel layer. Batch adsorption experiments showed that adsorption of SMP onto PVDF membrane was a spontaneous physical adsorption process.Meanwhile, the absolute value ΔG of adsorption of SMP onto D3520 was higher than that of adsorption of SMP onto PVDF membrane, so SMP preferentially adsorbed onto D3520 rather than PVDF membrane. Thus, the effect of ARs on reducing the SMP concentration was investigated. It was found that, 6 g of D3520 was suitable for adsorption of SMP. This physical adsorption involved external film diffusion, intra-particle diffusion, and surface adsorption. The Redlich–Peterson isotherm model performed best in terms of describing this equilibrium data. The mechanism of membrane fouling mitigation was verified by MBR simulation system. A case study of AR–MBR system was conducted. The results showed that addition of D3520 can effectively alleviate the development of membrane fouling.     

固定化酵母细胞发酵玉米芯酶解液生产木糖醇

用木聚糖酶对玉米芯的自水解液进行酶解以获得可发酵的木糖溶液。该法与直接用酶对玉米芯水解相比,水解速度快,木糖得率较高。所得酶解液发酵木糖醇的性能虽不如纯木糖,但明显优于玉米芯酸水解液。海藻酸钙/壳聚糖(ACA)微胶囊的最佳成膜时间和液化时间分别是18 min和20 min,微胶囊使用的环境pH范围是3～6。用微胶囊固定化细胞发酵玉米芯酶解液,重复培养了8批,平均木糖醇得率为61.4%。     

ACA液芯微胶囊制备工艺优化

采用响应面法优化工艺条件,制备具有较好机械强度的海藻酸盐-壳聚糖-海藻酸盐(ACA)液芯微胶囊。首先,通过Plackett-Burman方法对相关影响因素的效应进行评价,筛选出有显著效应的壳聚糖浓度、壳聚糖溶液pH值和柠檬酸钠溶液pH值3个因素;其次,采用最陡爬坡实验接近具有最好膜强度的中心点区域;最后由中心组合实验和响应面分析确定主要影响因子的最佳条件。在优化工艺条件下验证膜的机械强度,膨胀率-14.62%与优化结果-15.41%接近,优化结果与实际情况较好吻合。在优化条件基础上进行传质性能和细胞生长特性实验,研究结果表明ACA液芯微胶囊比ACA固芯微胶囊具有更好的传质特性,将ACA液芯微胶囊进行细胞包埋,液芯微胶囊较固芯微胶囊具有更高的细胞密度。     

Preparation of avidin-containing polyelectrolyte microcapsules and their uptake and release properties

Avidin-containing polyelectrolyte microcapsules were prepared by a layer-by-layer deposition technique and uptake and release of biotin-labelled fluorescein (b-FITC) was studied. The polyelectrolyte microcapsules were prepared by coating the surface of calcium carbonate (CaCO₃) microparticles containing avidin-poly(styrene sulfonate) (PSS) conjugate, followed by dissolution of CaCO₃ core in an ethylenediaminetetraacetic acid solution. Release of avidin from the microcapsules was markedly suppressed due to formation of a high molecular weight of avidin-PSS conjugate in the microcapsules. The uptake of b-FITC into the microcapsules was highly enhanced through a strong binding of b-FITC to avidin, as compared to the uptake into avidin-free microcapsules. Release of b-FITC from the microcapsules was accelerated upon addition of biotin, 2-iminobiotin, or lipoic acid in the solution due to the competitive binding of the additives to the binding site of avidin.     

预聚条件对相变材料微胶囊形态的影响

以三聚氰胺-甲醛树脂(M-F)为壁材,正十二醇为芯材,采用原位聚合法制备微胶囊相变材料。利用傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)和示差扫描量热法(DSC)分别对所得微胶囊的表面形态、结构及热性能进行表征。并针对微胶囊常有的结块、粘连和表面粗糙等问题,研究了预聚合反应条件对其黏度及其胶囊表面形态之间相关性。结果表明,预聚合体黏度过大时,易造成微胶囊之间的黏结和预聚体壁材的聚集。在预聚条件为反应温度72.5℃,反应时间75 min和pH值为8.5情况下,所得微胶囊表面光滑致密、分散性好且形态完整。     

Microencapsulation of sulfur in poly(urea–formaldehyde)

Poly(urea–formaldehyde) (PUF) microcapsules loaded with sulfur were prepared by in situ polymerization. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry and thermogravimetric (TG) analysis were used for the characterization of the obtained microcapsules. The chemical structure of the microcapsules was determined by FTIR. SEM analysis showed that the microcapsules were spherical and that the mean diameter of microcapsules was 42 ± 1 μm. Thermal analysis showed that the microcapsules were thermally stable below 247°C. The release properties of sulfur from the PUF microcapsules during the vulcanization of acrylonitrile–butadiene rubber (NBR) were studied by analysis of the vulcanization properties. The results show that at a vulcanizing temperature of 160°C, all of the sulfur entrapped in PUF was released out through the microcracks and pores of the shell, and the curing time of the microcapsule curing system compared with that of the sulfur curing system was longer. The mechanical properties of the NBR vulcanized by sulfur microcapsules were better than those of the NBR vulcanized by sulfur. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and Characterization of Microcapsules Containing Soybean Oil and Their Application in Self-Healing Anticorrosive Coatings

Synthetic self-healing materials are a new prototype in polymeric coatings. In the present investigation, soybean oil along with drier was encapsulated in urea–formaldehyde (UF) microcapsules, which were successfully prepared by in situ polymerization and their self-healing ability, the corrosion resistance, gloss, and adhesion strength of microcapsules were studied. The synthesized microcapsules were characterized by Fourier transform infrared spectrometer for identification of separated core and shell materials and their surface morphology was studied by scanning electron microscope. The particle size was checked under optical microscope and confirmed with particle size analyzer. Effectiveness of soybean oil-filled microcapsules was investigated for healing of cracks generated in anticorrosive coatings. Cracks in paint coatings were found to be healed when soybean oil was released from microcapsules under simulated mechanical action and the corrosion resistance of healed area was evaluated by immersion study.     

离子取代凝胶——ACA离子取代动力学模型

用动边界模型描述了海藻酸-壳聚糖-海藻酸(ACA)离子取代凝胶对2价离子的取代动力学过程.模型具有较好的可靠性，ACA离子取代凝胶对2价离子的取代属于颗粒扩散控制.ACA离子取代凝胶对Pb²⁺的反应级数是0.76.     

用微胶囊萃取铀

用微胶囊萃取铀倪沛红张明祖陈漫里严年喜（苏州大学化学化工学院，苏州２１５００６）关键词微胶囊萃取铀界面缩聚平均粒径１前言铀作为核燃料之一具有重要的应用价值。有关铀的提取方法已经研究得很多，主要是采用溶剂萃取的方法。八十年代以来，有关液膜法萃取铀的研究...     

Effects of surface modification of self‐healing poly(melamine‐urea‐formaldehyde) microcapsules on the properties of unsaturated polyester composites

Poly(melamine‐urea‐formaldehyde) (MUF) microcapsules used as self‐healing component of composites were prepared by in situ polymerization. The surface of MUF microcapsules was modified by 3‐aminopropyltriethoxy silane‐coupling agent (KH550). The interfacial interactions between MUF microcapsules and KH550 were studied by Fourier transform infrared spectra (FTIR). FTIR results show that the silane‐coupling agent molecule binds strongly to the MUF microcapsules surface. A chemical bond (Si? O? C) is formed by the reaction between the Si? OH and the hydroxyl group of MUF microcapsule. This modification improves the thermal properties of microcapsules. Optical microscope (OM) and scanning electron microscope (SEM) show that a thin layer is formed on the surface of MUF microcapsules. The interfacial adhesion effect between MUF microcapsules and unsaturated polyester matrix was investigated. MUF microcapsules disperse evenly in the composites. When crack propagated, the microcapsules were broken and the repair agent flowed from the microcapsules to react with the curing agent. Then the crosslinking structure was formed and the composite was repaired. The tensile properties, impact properties, and dynamic mechanical properties of composites have been evaluated. The results indicate that the silane‐coupling agent plays an important role in improving the interfacial performance between the microcapsules and the matrix, as well as the mechanical properties of the composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

交联聚脲囊壁微胶囊的制备

以异佛尔酮二异氰酸酯三聚体和三乙烯四胺为微胶囊壁材原料，在剪切乳化机的分散下通过界面聚合法制备出以交联型聚脲为囊壁结构的微胶囊。研究了有机溶剂种类、乳化剂种类以及剪毋分散速率等因素对微胶囊粒径大小与分布的影响，并分别用光学显微镜和扫描电镜观察分析了微胶囊的形貌。结果表明，微胶囊呈微米级球形结构；水溶性较大的油相介质和HLB很高的乳化剂都不利于微胶囊的形成；影响粒径大小与分布的主要因素是剪切分散速率。