空化水射流结合双氧水降解苯酚(英文)

The paper presents results of phenol oxidized under the conditions of high temperature created during collapse of cavitation bubbles.The degradation efficiency has been greatly improved by using cavitation water jets combined with H2O2 as demonstrated in laboratory tests.Various factors affecting phenol removal ratio were ex-amined and the degradation mechanism was revealed by high performance liquid chromatography(HPLC).The re-sults showed that 99.85% of phenol was mineralized when phenol concentration was 100 mg·L-1 with pH value of 3.0,H2O2 concentration of 300 mg·L-1,confining pressure of 0.5 MPa,and pumping pressure of 20 MPa.The in-termediate products after phenol oxidation were composed of catechol,hydroquinone and p-benzoquinone.Finally,phenol was degraded into maleic acid and acetic acid.Furthermore,a dynamic model of phenol oxidation via cavi-tation water jets combined with H2O2 has been developed.     

D318阴离子交换树脂对铼(Ⅶ)的吸附(英文)

The adsorption and mechanism of Re(Ⅶ)on resin D318 were studied using chemical methods and IR spectrometry.At pH 5.2,the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg·g-1,respectively.The adsorption behavior obeyed the Freundlich empirical equation and the adsorption rate constant k298 was 6.37×10-4s-1.The desorption percentage was up to 99.7%when 2.0 mol·L-1KSCN was used for dynamic desorption.     

静电强化乳液中油滴(纳米尺度)聚并过程(英文)

Oil droplets in nanometer scale which are dispersed in water cannot be separated easily.An attractive technique is carried out by electrical phenomena to demulsify oil in water emulsion.In this research,non-uniform electric field or dielectrophoresis(DEP) is applied to remove sunflower oil(which is dispersed in the water).Effects of temperature,time and voltage(using AC-electric field) were considered to get the highest DEP-force(Fdi) and the best results.The oil particles sizes with average of approximately 76 nm have been shown using a ZetaSizer Nano ZS,Model ZEN 1600(Malvern Instrument Ltd.).The maximum separation efficiency of 85% is obtained at the optimum temperature of 38 ℃ and voltage of 3000 V.     

等温或非等温颗粒吸附动力学模型:应用于吸附热泵(英文)

Understanding the interaction between a fluid and a solid phase is of fundamental importance to the design of an adsorption process.Because the heat effects associated with adsorption are comparatively large,the as-sumption of isothermal behavior is a valid approximation only when uptake rates are relatively slow.In this article,we propose to determine when it is needed to choose the isothermal or non-isothermal assumption according to two physical parametersα(ratio convection/capacity) andβ(quantity of energy/capacity) .The proposed problem is solved by a mathematical method in the Laplace domain.Whenα→∞(infinitely high heat transfer coefficient) or β→0(infinitely large heat capacity) ,the limiting case is isothermal.When the diffusion is rapid(α10) the kinetics of sorption is controlled entirely by heat transfer.If the adsorption process is to be used as a heat pump,it shall be represented by an isotherm model withαandβas high as possible.     

生物燃料工厂的能源与水资源的优化(英文)

In this paper we address the topic of energy and water optimization in the production of bioethanol from corn and switchgrass. We show that in order for these manufacturing processes to be attractive, there is a need to go beyond traditional heat integration and water recycling techniques. Thus, we propose a strategy based on mathematical programming techniques to model and optimize the structure of the processes, and perform heat integration including the use of multi-effect distillation columns and integrated water networks to show that the energy efficiency and water consumption in bioethanol plants can be significantly improved. Specifically, under some circumstances energy can even be produced and the water consumption can be reduced below the values required for the production of gasoline.     

303.15 K下氯化钙和氯化铵盐的溶解对甲醇+苯混合物焓的影响(英文)

The effect of two dissolved inorganic salts, cadmium chloride CdCl2 and ammonium chloride NH4Cl, on the excess enthalpy of mixing (HE) of the binary system methanol + benzene measured at 303.15 K using an isothermal displacement calorimeter with vapor space is investigated in the present work. Compared to the salt-free system, a decreasing trend in the endothermicity of HE values is significant with the addition of CdCl2 salt but the decrease in the HE values is insignificantly smaller with the addition of NH4Cl salt. The experimental values of the enthalpy of mixing are fitted into a Redlich-Kister equation and the deviations in the val-ues and the parameters are reported. The importance of the solute-solvent interactions and the solvent-solvent interactions are dem-onstrated from the increasing excess enthalpy of mixing values in the positive direction with the increase of salt concentration.     

脉冲超声对固定床中1300树脂吸附栀子甙吸附性能的影响(英文)

The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorption capability and the overall mass-transfer coefficient were obtained by fitting the constructed mass-transfer model and the experimental data. The effects of pulse ultrasound on adsorption of Geniposide on Resin1300 in a fixed bed were studied and compared. Amount of Geniposide adsorbed on Resin 1300 in the presence of ultrasound is lower than that in the absence of ultrasound, but the mass-transfer rate with ultrasonic irradiation is higher than that without ultrasound. Furthermore, mass transfer rate is enhanced by pulse modulation. In the conditions studied, the adsorption equilibrium constant decreases with increasing ultrasonic power, while the overall mass-transfer co-efficient increases. With increasing pulse duty ratio, adsorption equilibrium constant decreases initially, reaches a minimum when pulse duty ratio is 0.5, and then increases. On the contrary, the overall mass-transfer coefficient in-creases initially and reaches a maximum when pulse ratio is 0.5, and then decreases. Effects of pulse period on ad-sorption equilibrium and mass transfer rate reached the peak at pulse period of 28.6 ms.     

D72树脂对镨(Ⅲ)的吸附性能(英文)

In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.     

层状双金属氢氧化物的制备及其在处理阴离子污染物方面的应用

层状双金属氢氧化物(LDHs)是一类由带正电荷的金属氢氧化物和层间填充可交换的阴离子所构成的层柱状化合物.近年来,其在水处理方面的应用受到广泛的关注.本文综述了层状双金属氢氧化物的制备方法及其在处理废水中阴离子污染物方面的应用,并对今后的研究方向进行了展望.     

Synergistic Effect of Maghemite and Titania Nanoparticles in PVA-Alginate Encapsulated Beads for Photocatalytic Reduction of Pb(II)

In this paper, maghemite (γ-Fe₂O₃) and titanium oxide (TiO₂) nanoparticles were synthesized by hydrothermal and coprecipitation methods, respectively. These nanoparticles were combined together in various ratios (1:10, 1:20, 1:60, 1:80, and 1) and embedded in polyvinyl alcohol (PVA)-alginate beads. These beads were tested for photocatalytic behavior in eliminating toxic Pb(II) from the aqueous solution. The photocatalytic experiments were performed under sunlight irradiation and without sunlight. Several operating conditions such as initial Pb(II) concentration, pH, contact time, and TiO₂: γ-Fe₂O₃ ratios were investigated to evaluate their effect on the process. The recycling attributes of these beads were also investigated. The results revealed that 100% of the Pb(II) was eliminated in 100 min at pH 7 under sunlight when the ratio of TiO₂:γ-Fe₂O₃ was kept to 1. The PVA-alginate maghemite and titania beads showed better efficiency for Pb(II) removal than PVA-alginate titania beads and PVA-alginate maghemite beads. X-ray photoelectron spectroscopy (XPS) analysis also revealed that Pb(II) removal was via photocatalytic reduction due to the presence of Pb(0) in the high-resolution scan at 130–160 eV. Also, the PVA-alginate titania and maghemite beads can be readily isolated from the aqueous solution after the photocatalytic process and reused for at least 6 times without significant losses in their initial properties. The reduction of Pb(II) with PVA-alginate titania and maghemite beads fitted the Langmuir–Hinshelwood (L–H) kinetic model at a correlation coefficient (R²) of 0.9923.     

Zr4+掺杂对Mg/Al水滑石磷吸附行为的影响

采用共沉淀法制备了系列不同Zr4+含量的Mg/Al/Zr三元类水滑石材料，研究了其对废水中磷酸根离子的吸附性能。采用XRD、DRIFTS、氮气吸脱附实验等手段对材料的结构及织构性质进行了表征，并研究了溶液初始pH以及竞争阴离子对磷吸附量的影响。结果表明：掺杂Zr4+能提高类水滑石层板正电荷密度以及增大层间距，有利于磷酸根阴离子的吸附；Mg/Al/Zr类水滑石对磷的吸附过程符合准二级动力学模型，吸附等温线符合Langmuir模型，当n(Zr4+)/(Al3++Zr4+)为0.3时，理论饱和吸附量最大，达到76.6 mg/g，比Mg/Al水滑石高出28.7%；酸性环境有利于磷酸根的吸附，而二价阴离子的竞争吸附作用会显著降低磷吸附效果。Mg/Al/Zr类水滑石对磷的吸附机理为静电吸引和阴离子交换协同作用。     

阴离子交换纤维对磷酸根离子吸附性能及机理研究

以含偕胺肟基团的螯合纤维为原料,经Fe(NO3)3溶液处理,制得阴离子交换纤维,以其为吸附材料,对磷酸根离子进行吸附规律研究;并采用红外光谱仪(IR)和扫描电子显微镜(SEM)对样品进行了表征。实验结果表明,阴离子交换纤维对磷酸根离子的吸附反应符合Freundlich及Langmuir等温吸附模型,饱和吸附量为8.299 mmol/g。采用初始浓度法确定该反应为一级反应;在不同温度下对初始浓度为0.04994 mol/L的磷酸根离子进行吸附,测定了各温度下的反应速率常数,由速率常数与温度的关系得出反应的活化能Ea=22.55 kJ/mol,速率常数k=40.65 e-Ea/RT。     

阴离子交换树脂对茶氨酸的吸附动力学和热力学

以酶法制备茶氨酸,研究了碱性条件下阴离子交换树脂对茶氨酸的吸附与分离. 结果表明,强碱性树脂对茶氨酸的吸附性能优于弱碱性树脂,且其吸附容量受pH值的影响较小,pH=9.0时凝胶型强碱性树脂HZ202对茶氨酸的平衡吸附量可达96.3 mg/g. 对HZ202吸附茶氨酸的吸附等温模型及动力学、热力学参数进行了分析,结果表明,茶氨酸在HZ202树脂表面为非均一分布,Spis模型可较好模拟其吸附等温线数据;热力学参数计算结果显示,不同温度下吸附过程的吉布斯自由能变DG均为负值,表明吸附为自发的放热过程;吸附过程的焓变DH=20.9~418.4 kJ/mol,可判断其为化学吸附. 茶氨酸吸附过程符合准二级动力学方程,吸附过程受化学反应控制,提高茶氨酸初始浓度可提高吸附速率.     

Effect of pH on Fumaric Acid Adsorption onto IRA900 Ion Exchange Resin

The effects of pH on fumaric acid adsorption onto IRA900 ion exchange resin were studied. The optimum pH with the highest adsorption capacity depended on the fumarate concentration: the optimum pH was > 4.0 for fumarate concentrations < 5.0 g/L and < 3.0 for higher concentrations. Such different adsorption behaviors of IRA900 resins at different pHs were attributed to the different ion forms of fumarate present in solution at different pHs. Modeling results showed that the two-site-occupancy adsorption reaction between FA^2? and resin active sites contributed to the high adsorption capacity at pH 5, whereas the intraparticle diffusion resulting from the hydrophobic interaction between H₂FA and the hydrophobic resin backbone of IRA900 increased significantly and led to a higher adsorption capacity at pH 3.     

Removal of Nitrate from Water by Adsorption onto Zinc Chloride Treated Activated Carbon

Abstract

Adsorption study with untreated and zinc chloride (ZnCl₂) treated coconut granular activated carbon (GAC) for nitrate removal from water has been carried out. Untreated coconut GAC was treated with ZnCl₂ and carbonized. The optimal conditions were selected by studying the influence of process variables such as chemical ratio and activation temperature. Experimental results reveal that chemical weight ratio of 200% and temperature of 500°C was found to be optimum for the maximum removal of nitrate from water. Both untreated and ZnCl₂ treated coconut GACs were characterized by scanning electron microscopy (SEM), Brunauer Emmett Teller (BET) N₂‐gas adsorption, surface area and Energy Dispersive X‐Ray (EDX) analysis. The comparison between untreated and ZnCl₂ treated GAC indicates that treatment with ZnCl₂ has significantly improved the adsorption efficacy of untreated GAC. The adsorption capacity of untreated and ZnCl₂ treated coconut GACs were found 1.7 and 10.2 mg/g, respectively. The adsorption of nitrate on ZnCl₂ treated coconut GAC was studied as a function of contact time, initial concentration of nitrate anion, temperature, and pH by batch mode adsorption experiments. The kinetic study reveals that equilibrium was achieved within one hour. The adsorption data conform best fit to the Langmuir isotherm. Kinetic study results reveal that present adsorption system followed a pseudo‐second‐order kinetics with pore‐diffusion‐controlled. Results of the present study recommend that the adsorption process using ZnCl₂ treated coconut GAC might be a promising innovative technology in future for nitrates removal from drinking water.     

麦草阳离子型吸附剂的合成及对硝酸根的去除

以环氧氯丙烷为醚化剂,二甲胺为反应剂,对麦草秸秆改性合成阳离子型吸附剂。该文以改性后产物对NO3-的去除率为指标,分别考察了制备过程中单一影响因素,并结合正交实验得出影响因素结论与最佳改性条件。实验结果表明,催化时间是影响麦草秸秆改性效果的主要因素,麦草投加量、催化剂用量、二甲胺用量、活化反应和反应时间是次要因素;最佳改性条件为,当固定环氧氯丙烷和N,N-二甲基甲酰胺分别为20 mL和25 mL时,麦草投加量是2 g,催化剂用量是15 mL,二甲胺用量是30 mL,活化时间1 h,催化时间1 h,反应时间3 h。在此条件下硝酸根的去除率可达78.13%。     

聚硅酸氯化铁的混凝实验研究及在海水预处理中的应用

用自制聚铁和硅酸钠制备的聚硅酸氯化铁处理模拟水样。考察了絮凝剂的加入量、处理水样的pH值、搅拌速度和搅拌时间等对絮凝效果的影响,同时对自制絮凝剂与市售聚铁铝絮凝剂对海水的絮凝效果做了比较。结果表明:该絮凝剂在加入量为42mg/L、快搅速度为240r/min、慢搅时间为16min、静置30min、酸碱度为中性或略碱性时絮凝效果较好。对海水的探索性实验中,自制絮凝剂优于其它几种。