强碱性阴离子交换纤维在糖汁脱色中的应用

研究了ZB-2型聚丙烯(PP)基氯型强碱性阴离子交换纤维(IEF)对糖厂糖汁的脱色性能,考察了糖汁温度、糖汁流速、装填高径比等因素对脱色效果的影响。通过静态、动态试验找到脱色的较好条件,为实现离子交换纤维在糖厂应用的工业化提供实验依据。结果表明,此种离子交换纤维对清汁的脱色温度在65~80℃,流速2.8 mL/m in,高径比11时,脱色效果明显,处理糖液量为100 g/mL,是一种具有较好应用前景的脱色材料。     

硝酸替代盐酸作再生剂在阳浮床中的应用

阳离子交换树脂的再生剂通常采用盐酸,较少采用硝酸。用3%~5%稀硝酸液(镁尾水)取代30%工业酸作为再生剂对阳离子交换树脂进行再生,控制再生剂的质量分数在2.4%,流速为6m/h,再生时间为3h;生后的阳浮床出水水质、运行周期和周期制水量与用盐酸再生的阳浮床相比差别不大。阳离子交换树脂的再生剂通常采用盐酸,较少采用硝酸。用3%~5%稀硝酸液(镁尾水)取代30%工业盐酸作为再生剂对阳离子交换树脂进行再生,控制再生剂的质量分数在2.4%,流速为6m/h,再生时间为3h;再生后的阳浮床出水水质、运行周期和周期制水量与用盐酸再生的阳浮床相比差别不大。     

脱盐工艺离子交换树脂再生技术的探讨

探讨了在一定工艺条件下,再生剂用量、浓度、流出时间、温度对离了交换树脂再生状况的影响。     

球形再生纤维素磷酸型离子交换剂

本文叙述一种用再生纤维素白球为基体制备磷酸型离子交换剂的方法。并对这种交换剂的性能进行了测试,总交换容量达3.2mMol/g。     

阴离子交换纤维对活性染料废水的脱色研究

采用自制的聚丙烯基强碱阴离子交换纤维(IEF)处理活性染料模拟废水,讨论了IEF用量、介质pH值、温度等对活性艳黄X-RG溶液的脱色率和脱色速率的影响。对比了IEF与树脂、锰钾矿的脱色效果, 进行了动态脱色和再生实验。结果表明,IEF用量、pH值和温度的增加有利于脱色速率的提高,对活性艳黄和活性艳红染料的脱色率在96%以上,脱色40 mm即能达到高脱色率IEF对活性染料的脱色效果明显优于天然锰钾矿和D296强碱性阴离子交换树稽,IEF能够再生重复使用     

离子交换法处理线路板厂含铜废水工艺的优化

对某线路板厂含铜废水处理装置的离子交换柱再生工艺条件进行了优化.结果表明,当再生液流量为2000L/h,再生剂质量分数为8.5%时,每次交换出的总铜量达26.1～29.0 kg;采用再生液二次利用工艺时,每次交换出的总铜量为18.5～21.3 kg,废再生液Cu2 质量浓度上升到20g/L,可节约再生剂用量,并有利于铜的回收.     

糖醇高效液相色谱柱的再生

介绍了一种糖醇高效液相色谱柱的再生方法。考察了温度、再生液浓度、再生顺序、再生时间、再生流速等因素，对液相色谱柱再生效果的影响。结果表明，在温度为85℃，再生液浓度为0．2mol／L时，以0．2mL／min的再生流速，用硝酸钙溶液对色谱柱进行24h的再生，取得的再生效果比较好。     

离子交换法处理含Cr(Ⅵ)废水的研究

采用201×7强碱性阴离子交换树脂处理模拟含Cr(Ⅵ)废水,探讨了废水酸度、交换时间、浓度对Cr(Ⅵ)去除率的影响以及树脂再生所需的合适温度和再生剂浓度。结果表明,201×7强碱性阴离子交换树脂处理模拟含Cr(Ⅵ)废水,具有交换容量大、交换效果好、树脂再生条件较简单等优点。并对实际含铬废水进行了处理,废水中Cr(Ⅵ)的初始浓度为1 540 mg/L,处理量达52 BV(床体积)时,出水中Cr(Ⅵ)的浓度仍小于0.5 mg/L,达到国家排放标准。树脂交换容量约80 mg/g。用8%NaOH溶液,在50℃条件下进行再生效果较好,再生率大于95%,可实现树脂的重复使用。     

混床离子交换柱中的离子交换树脂的再生Ogawa, Shozo等（ Japan Organo Co.,Ltd., Japan）

在混床离子交换柱的树脂再生中，分别将碱性再生剂和酸性再生剂注入到阴离子树脂层和阳离子树脂层，然后用水将再生剂排到交换柱的外面，再用水清洗阴、阳二层树脂，然后从交换柱的下面通水进行反洗，该混床交换柱可用于生产电厂的补水。     

道路沥青再生添加剂的研究

为了再生高速公路路面老化沥青,针对路面老化沥青特点,将自制的7种再生添加剂加入到经过旋转薄膜烘箱老化的沥青中,通过老化沥青前后软化点、针入度、延度的对比,筛选出再生效果最优的再生剂。将再生后的沥青与重交通石油沥青规格(GB50092—96)比对确定所选再生剂的最佳用量为3%。为测试自制再生剂的实际再生效果,将筛选出的再生剂添加到京沈高速公路新民段的废旧回收沥青中,结果表明,经再生添加剂再生后的路面老化沥青路用性能可完全恢复。     

Modelling of Cr(VI) removal from polluted groundwaters by ion exchange

This work reports the viability and modelling of the removal of Cr(VI) from polluted groundwaters by means of ion exchange using the resin Lewatit MP‐64. Feed groundwaters that contained Cr(VI) at an average concentration of 2431 mg dm^?3 and 1187 mg dm^?3 of chloride and 1735 mg dm^?3 of sulfate as main anions were acidified to a pH of 2.0 prior to the removal process. Dynamic experiments were carried out in a fixed bed column with feed waters at flow rates in the range of 2.78 × 10^?7 m³ s^?1 to 5.55 × 10^?7 m³ s^?1. Regeneration was achieved with NaOH (2 mol dm^?3). From the experimental results, the equilibrium of the ion exchange reaction was successfully modelled, obtaining an equilibrium constant (K′_AB) = 44.90. Finally, a mass balance that included mass transfer resistances in the liquid and solid phases was developed and from the comparison between simulated and experimental data the value of the effective intraparticle diffusivity (D_s) was determined as 1.43 × 10^?12 m² s^?1. Copyright © 2004 Society of Chemical Industry     

Novel hollow‐fiber anion‐exchange hybrid membranes: Preparation and characterization

To develop ion‐exchange membranes for application in severe conditions, such as those with high temperatures, strongly oxidizing environments, or organic solvents, new hollow‐fiber anion‐exchange hybrid membranes were prepared by the immersion of brominated poly(2,6‐dimethyl‐1,4‐phenylene oxide) base hollow fibers in a tetraethoxysilane–ethanol solution followed by sol–gel and quaternary amination. Compared to conventional polymeric charged membranes, the prepared hybrid membranes were higher in both thermal and dimensional stabilities. The results suggest that tetraethoxysilane concentration was an important factor affecting the membrane's intrinsic properties. When the tetraethoxysilane concentration was in the range 15–45%, the final hollow‐fiber anion‐exchange hybrid membranes had an ion‐exchange capacity of 1.9–2.0 mmol/g, a water uptake of.83–1.23 g of water/g of dry weight, and a dimensional change ratio of 13–18%. An evaluation on the membranes' separation performances is underway. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Catalytic combustion of methane over palladium exchanged zeolites

Palladium cation exchanged zeolites (ZSM-5, mordenite and ferrierite) were studied as catalysts for methane combustion. Pd-zeolites showed much higher activities than PdO/Al₂O₃. For comparable palladium loadings, PdO/Al₂O₃ requires a reaction temperature of ca. 70–80°C higher than Pd-ZSM-5 for conversions between 50–100%. The catalytic activity of Pd-ZSM-5 seems to be related to its reducibility. Temperature-programmed reduction experiments with carbon monoxide showed a lower reduction temperature (ca. 157°C) for Pd-ZSM-5 than for PdO/Al₂O₃ (225°C). Further, the positioning of the palladium by ion exchange offers a highly dispersed form of Pd^II supported on the high surface area zeolite.     

Effect of Divalent Metal Cations on Contaminant Removal by Bicarbonate-Form Anion Exchange Resin

This work investigated the role of divalent metal cations (Mg²⁺, Ca²⁺, and Cd²⁺) and subsequent precipitation or complexation on decreased contaminant removal by bicarbonate-form anion exchange resin (AER-HCO₃) relative to chloride-form AER (AER-Cl). The results showed that the removal of dissolved organic carbon and nitrate was lower for AER-HCO₃ than AER-Cl, and contaminant removal by AER-HCO₃ was affected by the presence of metal cation. For instance, magnesium and cadmium exhibited the greatest and least interference, respectively, with contaminant removal by AER-HCO₃. The results suggested that precipitation was not the cause of decreased contaminant removal by AER-HCO₃, and instead implied that complex formation between the contaminant and divalent metal was responsible for differences in removal by AER     

GO@MIL-101的制备及其对水中Cr（Ⅵ）的去除

通过水热法制备了掺杂氧化石墨烯（GO）的金属有机框架GO@MIL-101,并考察了GO掺杂量对GO@MIL-101形貌和性质的影响规律。GO的掺杂影响了MIL-101晶体的形成过程。随着GO掺杂量的增加,GO@MIL-101晶体的完整性降低、粒径减小,团聚现象越发显著。GO@MIL-101能够有效去除溶液中的Cr（Ⅵ）,该过程符合拟二级动力学方程。由Langmuir吸附等温线拟合得到的最大吸附量与GO掺杂量有关,在2%[相对于Cr（NO₃）₃·9H₂O质量]时达到最大,这与此时GO@MIL-101同时具有较大的比表面积和较大的孔体积有关。Cr（Ⅵ）的去除过程伴随着溶液中NO₃^-浓度的升高以及pH的下降,电荷平衡计量分析表明MIL-101和GO@MIL-101对Cr（Ⅵ）的去除机制相同,主要依靠MIL-101的离子交换作用,并且所去除的Cr（Ⅵ）以CrO₄^2-形式存在于固相中。     

电厂反渗透及离子交换除盐系统去除水中有机物的试验

该文介绍了安徽省火电厂锅炉补给水处理系统中反渗透及离子交换除盐系统去除水中TOC的情况,比较了不同水处理工艺去除水中TOC的情况。结果表明省内火电厂的除盐水TOC含量基本上都能满足《火力发电机组及蒸汽动力设备水汽质量》(GB/T 12145—2008)中对除盐水TOC含量的要求。除盐水TOC含量主要取决于所采用的水处理工艺流程,基于反渗透的水处理工艺对水中的TOC去除率最高,除盐水的TOC含量也最低。     

Ion Exchange of the Organometallic Aqua‐Ion fac‐[99mTc(CO)3(H2O)3]+ from Aqueous Solutions

Dynamic (column) studies on the ion exchange of triaquatricarbonyltechnetium(I) cation, fac‐[^99mTc(CO)₃(H₂O)₃]⁺ (1), in the system: amphoteric ion exchange resin (Purolite S‐950) ‐ aqueous HNO₃ solutions (0.05–2 M) corroborate the +1 charge of 1. Stability constants of fac‐[^99mTc(CO)₃(H₂O)_3?nCl_n]^1?n complexes, determined from the distribution coefficients in the system anion exchanger (Dowex 1X4) ‐ aqueous HCl solutions (0.1–12 M) differ from the literature values determined at a constant ionic strength. This difference, resulting from the decrease in the activity of water with increasing HCl concentration, may be a measure of the effect of non‐constant ionic strength on ion‐exchange equilibria. Weak acidic properties of 1 in aqueous solution at n.c.a. (no carrier added) level (pK_a ?9) have been demonstrated by paper electrophoresis.     

Ion exchange properties of polypyrrole studied by electrochemical quartz crystal microbalance (EQCM)

The electrochemical polymerization of pyrrole in aqueous solution was studied as a function of a variety of parameters, such as magnitude of current density and monomer concentration. The possibility of quantitative replacement of counterions by solution anions was studied in detail using the electrochemical quartz crystal microbalance (EQCM) technique. It was found that the polymer structure can be manipulated, even after synthesis. The manipulation was revealed to be dependent on various factors, including the nature of the counterion and of the electrolyte concentration. On the basis of these observations, a two-layer structure is suggested for polypyrrole-based polymers. © 1999 Society of Chemical Industry     

Tilapia scales: characterization and study of Cu(II) removal by ion exchange with Ca(II)

ABSTRACT

A biosorbent material based on tilapia scales for the removal of Cu(II) ions was investigated. Modifications in the biosorbent caused by retention of Cu(II) and by the pH effect were evaluated separately in order to comprehend how the removal process occurs. For that, a physico-chemical characterization of the scales was performed before and after the Cu(II) removal. The results obtained from the characterization and biosorption tests led to the conclusion that the Ca–Cu ions exchange was responsible for purifying the solution. Furthermore, the tilapia scales were efficient, removing 95% of Cu(II) with 1 g of adsorbent (surface area ≈ 3 m²).