The conditions of cationic exchange with the use of recycling polystyrene derivative,the product of sulfonation by silica sulfuric acid

Growing amount of waste plastics has become an environmental problem on a global scale. This study presents an investigation of the conditions of cleaning water from heavy metal ions using chemically recycled polystyrene. To get effective ion exchangers, the sulfonation of virgin polystyrene and expanded polystyrene wastes were obtained using silica sulfuric acid. As it turned out, the use of this solid sulfonating agent simplifies the separation of the polymeric product from the acid and the solvent in comparison to conventional sulfonation methods. The ion exchange behavior of copper and zinc cations in the yielded sulfonated derivatives of polystyrene was studied. Batch shaking adsorption experiments depending on contact time, pH, temperature, and dosage of adsorbate were carried out. The stability of resin to cyclical adsorption and regeneration (column experiment) was also investigated. We report that resins have a high adsorption efficiency with total ion exchange capacity (IEC) about 2.6 meq g^?1, which drops with decreasing pH owing to competition between protons H⁺ and metal cations, whereas with the increasing resin doses the removal of cations rises for a constant initial metal concentration. The speed of cation exchange for yielded adsorbents was even better than for commercial resins. After 360 cyclical adsorption and regeneration in column, resin had working IEC of about 2.3 meq g^?1. The study shows that cation exchange resin from polystyrene wastes can be used as an efficient adsorbent for the removal of heavy metal ions from water. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Batch and column adsorption of perfluorooctane sulfonate on anion exchange resins and granular activated carbon

Perfluorooctane sulfonate (PFOS) has been detected widely in the natural water matrix and is persistent, bioaccumulative, and toxic. To prevent the adverse effects of PFOS contamination on human health and the environment, effective removal techniques are needed. Adsorption is considered an effective technique for PFOS removal. In this study, five anion exchange resins and granular activated carbon (GAC) were examined to evaluate their performance for the removal of PFOS in both batch and column experiments. Experimental adsorption data for all of the adsorbents exhibited a high correlation with the Freundlich isotherm (R² = 0.95 – 0.98). Most of the anion exchange resins demonstrated a higher adsorption capacity than the GAC. PFA300 had the highest adsorption capacity (455 mg/g). Continuous adsorption of PFOS was performed in column experiments using the same adsorbents that had been used in the batch experiments. The experimental breakthrough curves were set at C/C₀ = 0.1. PFA300 showed the longest operation time before reaching the breakthrough point. The Yoon and Nelson model was used to predict the half‐saturation time of the anion exchange resins. Moreover, the anion exchange resins exhibited high recovery of PFOS by an organic solvent. Continuous PFOS adsorption on a column can be achieved using anion exchange resins for water/wastewater treatment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39782.     

Synthesis of cyclodextrin‐based polymers and their use as debittering agents

Cyclodextrins (CDs) and their derivatives are used to suppress unpleasant tastes and odors or to achieve a controlled release of certain food constituents. This article describes the synthesis by nonconventional methods of (1) crosslinked, insoluble CD polymers and (2) water‐soluble, CD‐grafted carboxymethylchitosan and carboxymethylcellulose. The CD polymers were obtained by the reaction of β‐CD with one of the following crosslinking agents: epichlorohydrin, diphenyl carbonate, or hexamethylene diisocyanate. Their preparations were usually carried out under high‐intensity ultrasound, which resulted in much shorter reaction times and narrower distributions of particle size (as determined by scanning electron microscopy measurements). A novel, insoluble CD polymer was obtained by reticulation under microwaves of propargyl‐β‐CD with 1,3‐bis(azidomethyl)benzene through Huisgen 1,3‐dipolar cycloaddition. Short columns packed with the insoluble polymers were found to efficiently sequester naringin from aqueous solutions; successively, they could be easily regenerated by a counter‐current ethanol wash that also achieved an excellent recovery of the flavonoid. Differential scanning calorimetry thermograms showed that the crosslinked CD polymers formed inclusion complexes with naringin. The soluble polymers also interacted with bitter flavonoids of citrus fruits (naringin and limonin), as shown by the results of sensorial panel tests, in which they behaved as bitter‐masking agents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Bifunctional Phosphinic Acid Resins for the Complexation of Lanthanides and Actinides

Abstract

Phosphinic acid ion exchange/redox resins are synthesized by the reaction between polystyrene beads and phosphorus trichloride followed by base hydrolysis. The reaction requires a temperature of 73°C for full functionalization to occur. The effect of lower functionalization temperatures on resin acid capacity was determined and the concomitant effect on ion exchange investigated. The acid capacity was found to vary from 1.68 mequiv/g to 4.79 mequiv/g in the functionalization temperature range studied (15°C to 73°C). The percent resin sites loaded with zinc ions is independent of the actual capacity. The extracting ability of the phosphinic acid resin for europium, thorium, uranium, americium, and plutontutn was examined as a function of acid concentration from acid nitrate solutions both at varying and constant ionic strength. The phosphinic resins show better extraction for these ions than the sulfonic resins, especially from high acid solution (4M HNO₃) due to the superior coordination ability of the phosphoryl oxygen. They also show a higher selectivity for the ions tested over sodium. For example, under conditions where sulfonic resins absorb 85% of the plutonium in solution, the phosphinic acid resins absorb 99.7%.     

吸附法去除水体中单宁酸的研究进展

介绍了吸附法去除水体中单宁酸的研究应用,阐述了活性炭、改性黏土、壳聚糖和树脂吸附剂去除单宁酸的研究进展,将各种吸附剂的去除效果、去除机理进行了比较。研究结果表明复合功能树脂在去除难处理有机物方面具有广阔的应用前景。     

The synthesis of spherical activated carbons containing zinc and their photochemical activity

Spherical activated carbon (AC) containing photocatalyst was prepared using strong and weak acid ion-exchange resins as starting materials. These resins were treated with an aqueous solution of Zn²⁺ or [Zn(NH₃)₄]²⁺ and both treated resins and non-treated resins were carbonized and activated. The physicochemical characteristics of the AC samples were examined using XRD, SEM, EDS, BET, EPMA, ESR, compressive strength and zinc content. The photocatalytic activity was evaluated by measuring the humic acid (HA) removal efficiency using UV/photocatalyst system. When strong acid ion-exchange resins (SZ samples) were used to prepare AC containing zinc, the zinc was found to have ZnS crystal structures, whereas in case of the use of weak acid ion-exchange resins (WZ samples), the zinc was found to have ZnO crystal structure. Both the SZ and WZ samples had spherical shape except the WZ-A-900 and had a good BET specific surface area. In the HA removal test using a floating UV/photocatalyst system, the WZ samples showed higher HA removal efficiency than the SZ samples.     

Chemical modification of polystyrene. V. Sulfonic acid resins from anhydride substituted polystyrene

Chemically modified polystyrenes based on the condensation of polystyrene with phthalic anhydride, trimellitic anhydride, and cis-1,2,3,6-tetrahydrophthalic anhydride have been processed into sulfonic acid cation exchange resins. The effects of variation of sulfuric acid amount and the temperature of sulfonation on the synthesis and the ion-exchange capacities of the resins have been established. The resins have finally been characterized with respect to their structures by IR and elemental analysis data. The total ion exchange capacity as well as the salt-splitting capacity and the pH-metric titration characteristics of these resins have also been determined. These resins posses better ion-exchange capacities than the conventional styrene based resins.     

改性吸附剂去除废水中磷的应用研究进展

去除废水中过量的磷可以减缓水体富营养化。吸附除磷因具有能耗低、容量大、污染少等优点而备受关注，改性吸附剂则可在此基础上提高除磷的靶向性，拓宽操作条件，增大吸附容量。本文分析了改性硅酸盐类、改性金属氧化物类、改性固体废弃物类和聚合物类4类除磷吸附剂的改性方法和吸附性能。硅酸盐类吸附材料以及固体废弃物类材料除磷效果略差，但因来源丰富、价格低廉而具有极大的吸引力。聚合物类吸附剂具有高吸附容量、高选择性，但价格昂贵。金属（氢）氧化物具有出色的磷酸盐吸附性能，且选择性好、吸附速度快，这些化合物已被掺入到沸石、介孔二氧化硅和生物炭等材料中，进一步增强其吸附性能，并在工程材料应用中取得重大突破，主要包括磁性吸附剂和颗粒吸附剂。4类吸附剂的作用机理可归纳为两种：一种是吸附剂上的金属与磷酸盐离子发生配位反应，形成沉淀；另一种是酸性条件下吸附剂上的羟基质子化，使羟基带正电，质子化的羟基通过静电吸引使磷得以去除。通过对不同类别吸附剂的吸附特性进行对比分析，提出将高分子技术运用到吸附剂制备过程中，开发同时具有较强解吸能力的改性吸附剂将成为除磷吸附剂研究的新热点。     

A practical review of the performance of organic and inorganic adsorbents for the treatment of contaminated waters

A wide range of materials known for their adsorption properties have the potential for being used for the removal of trace substances from drinking and wastewaters. These include physically and chemically activated carbons, surface modified carbons, non‐porous resins with ion exchange capacities, inorganic microporous solids like zeolites and clays, and mixed organic–inorganic materials like bone chars. The adsorption capacity exhibited by each material relates primarily to its textural and chemical properties. Other factors, however, such as apparent density, regeneration potential and cost, need to be taken into consideration when selecting one adsorbent over another. A comparative investigation of 18 solids and their capacity to remove organics and metals from natural waters and solutions reconstituted to simulate the conditions in natural waters is presented. The experiments were carried out using batch and small‐scale column adsorption tests. In general, zeolites and ion exchange resins exhibited limited capacities to remove organic matter from solution but were highly effective with metallic species like manganese and aluminium. Activated carbons adsorbed organic matter very efficiently, with results showing a correlation between adsorption capacity and surface area (up to 1791 m² g^?1). Metal removal was highly variable and was enhanced in activated carbons subjected to acid washing. Owing to its mixed organic/inorganic nature, and despite its poorly developed micropore structure, bone char exhibited a strong adsorption capacity for both organic and metal species. The high apparent density of this material (0.763 g cm^?3) meant that its performance was greatly improved when tests were conducted on the basis of volume, matching and surpassing the performance of the best carbons. The possibility of using mixtures of complementary adsorbents for the removal of organic and inorganic species from solution was also successfully evaluated in this work. Copyright © 2006 Society of Chemical Industry     

氨基丙二醇功能化硼螯合树脂的制备及其硼酸吸附性能

分别用3-氨基-1,2-丙二醇（3-APD）和2-氨基-1,3-丙二醇（2-APD）对多孔氯甲基聚苯乙烯树脂（CMPS）进行修饰,制备得到含邻、间位二羟基官能团的硼螯合树脂：PS-3-APD和PS-2-APD。用傅里叶红外光谱仪（FTIR）、元素分析仪（EA）、压汞仪（MIP）和激光粒度仪（LPS）对材料进行表征,确认功能单体成功接枝于氯球上。对两种树脂进行了静态提硼性能研究,分别考察了原料液pH、初始硼酸浓度、外来金属离子对硼酸吸附量的影响,当溶液pH为9.15～9.20时,两种树脂对硼酸吸附量最大;溶液中Na⁺、Mg²⁺、Ca²⁺的存在会一定程度削弱树脂对硼酸吸附性能。吸附动力学表明其吸附速率较快,且均满足准二级动力学模型。与Freundlich相比,吸附等温线更符合Langmuir模型,拟合得到的理论最大吸附量分别为0.730mmol/g和0.868mmol/g。本文对未来新型硼螯合树脂的开发及工业化应用提供参考和指导。     

Sorption of dissolved organics from aqueous solution by polystyrene resins—I. Resin characterization and sorption equilibrium

The results of sorption equilibrium studies indicate that adsorption is only one of the three mechanisms involved in removing organics from aqueous solution by polystyrene resins. The other two mechanisms are associated with the resin's capability to incorporate organics into their polymer matrix while swelling. To describe the overall sorption behaviour, it is not sufficient to characterize the resin structure by estimating pore size distribution and internal surface area of the dry polymers. The amount of swelling in different organic solvents must also be evaluated as an important structural parameter of polystyrene resins. The role of the different mechanisms depends on both the resin structure and the physical and chemical properties of the solute. The solute's affinity for the polystyrene surface can be correlated with the solute's benzene-water partition coefficient. A heuristic model is presented which relates the sorption capacity to both the resin and solute properties.     

Surface Functionalization of PVDF Membrane with a Naringin-Imprinted Polymer Layer Using Photo-Polymerization Method

The aim of this work was the preparation of molecularly imprinted membranes by surface modification of microfiltration polyvinylidene fluoride membranes with a thin layer of molecular imprinted polymer by UV irradiation. The flavonoid naringin (4,5,7-trihydroxyflavanone-7-rhamnoglucoside) was used as template molecule. The compound 4-vinylpyridine was used as functional monomer. Benzoin ethyl ether and ethylene glycol dimethacrylate were used as photo-initiator and cross-linker, respectively. Membranes were also modified in the absence of naringin and used as reference (blank). Imprinted membranes prepared in this work could be applied as new separation devices in affinity filtrations aimed to reduce the naringin content in grapefruit and improve its benefit properties. The method used to prepare them offers the advantage of combining the mechanical integrity of the membrane support with the selective recognition properties of the imprinted polymer layer. The recognition properties of all prepared membranes were evaluated by their capability to retain naringin in aqueous solution during filtration tests. Results showed that imprinted membranes exhibited specific binding properties for template molecules. Blank membranes only showed non-specific binding. The selectivity of the naringin-imprinted membranes was tested evaluating their bound property toward the rutin, a structural analogue of naringin.     

Macroporous polystyrene resins as adsorbents for the removal of tetracycline antibiotics from an aquatic environment

Six macroporous polystyrene resins (strong‐acid resins D001, D061, D072, and NKC‐9, strong‐base resin D201, and alkalescent resin D370) were selected as adsorbents for removing tetracycline (TC) and doxycycline hydrochloride (DC) from aqueous solutions. The solution pH and ionic strength had significant effects on the sorption of TC and DC. The basic resins D201 and D370 exhibited strong sorption capabilities (70.08–105.60 mg/g) at pH 4–9, but strong‐acid resins showed good sorption abilities only under acidic conditions of pH 2–3 (83.30–95.78 mg/g). The inhibitory effect of the ionic strength was much weaker for D370 than for D201. The adsorption ratio of TC and DC on D201 and D370 were all above 90% when the amount of adsorbent exceeded 50 mg. By performing kinetic experiments, we determined that the pseudo‐second‐order model fit the data best for DC sorption on the six resins and TC sorption on D201 and D370, but the pseudo‐first‐order model fit the data of TC sorption on the four strong‐acid resins better at pH 7.0. Intraparticle diffusion was not the only rate‐controlling step, and an initial external mass transfer or chemical reaction might have existed in the sorption process. The Langmuir equation was the best isotherm equation to describe the sorption with a monolayer sorption maximum larger than 98.04 mg/g under all temperatures. Thermodynamic studies showed that the sorption of TC and DC on the resins was thermodynamically feasible and spontaneous. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40561.     

Removal of cationic dye from aqueous solution by adsorption onto crosslinked poly(4-vinylpyridine/crotonic acid) and its N-oxide derivative

In this study, crosslinked poly(4-vinylpyridine/crotonic acid) [poly(4-VPy/CrA)] and its N-oxide derivative were synthesized to compare the adsorption of cationic methylene blue (MB) dye on these materials. The adsorptive removal of MB from aqueous solution onto adsorbents was studied by using column adsorption method. Experimental results showed that MB was removed more effective by poly(4-VPy/CrA)–N-oxide than poly(4-VPy/CrA) resins. The percentage removal of MB increased with pH, and it was observed that basic pH was favorable for the adsorption of MB. The adsorption capacity for poly(4-VPy/CrA)–N-oxide resin was found to 19.96 mg/g. It was found that the adsorption isotherm of the MB-fitted Langmuir-type isotherm. For the adsorption of MB, the pseudo-second-order chemical reaction kinetics provides the best correlation with the experimental data. Ten adsorption–desorption cycles demonstrated that the resins were suitable for repeated use without considerable change in adsorption capacity.     

Importance of Surface Area and Pore Size Distribution of Resin for Organic Toxicants Adsorption

Adsorption of benzoic acid and reactive brilliant blue 4 (RBB4) by hypercrosslinked resins and macroporous resins was examined. Micropore areas were much higher in the hypercrosslinked resins than macroporous resins while the pore volume and average pore diameter of macroporous resins were superior to the hypercrosslinked resins. The investigation showed that the pore size distributions of the resins significantly influenced the adsorption capacity of adsorbents. Adsorption of benzoic acid was dominated by BET surface area and the micropore area while the adsorption of RBB4 shifted to a pore-size-dominant process. The maximum mol adsorption capacities of benzoic acid were all higher than those of RBB4 by the resins, showing the influence of the molecular dimension on adsorption. The adsorption thermodynamic parameters were calculated and it revealed that the adsorption was an exothermic, spontaneous, and more ordered process. Adsorption kinetics and elution processes were also investigated for establishing the appropriate adsorption conditions for purifying wastewater containing benzoic acid or RBB4.     

2,4-二羟基苯甲酸在3种树脂上的吸附特性

通过静态和动态吸附实验, 研究了717(凝胶型,强碱)、D201(大孔型,强碱)和D301R(大孔型,弱碱)3种阴离子交换树脂对水溶液中2,4-二羟基苯甲酸的吸附特性. 结果表明,717和D201在pH 4~11时、D301R在pH 3~9时吸附能力最好. 在pH=5及温度293~313 K、初始浓度0.6488~6.488 mmol/L条件下,D301R, 717和D201对2,4-二羟基苯甲酸的等温吸附规律均符合Freundlich模型,最大平衡吸附量分别为2.98, 2.66和2.54 mmol/g(吸附未达饱和),均为物理性自发吸附的放热过程. 动力学实验数据用准一级模型方程拟合比准二级更接近实验值. 5%(w) NaCl+2%(w) NaOH脱附液100 mL均可有效洗脱3种树脂上吸附的2,4-二羟基苯甲酸,脱附率达99%. 相同条件下,D301R树脂对2,4-二羟基苯甲酸的吸附性能优于D201和717树脂.     

胺化聚苯乙烯树脂的制备及吸附对硝基酚

以氯甲基化聚苯乙烯树脂(PS-Cl)和氯乙酰化聚苯乙烯树脂(PS-Acyl-Cl)为母体, 引入三乙烯四胺(TETA)制备两种胺化聚苯乙烯树脂PS-TETA与PS-Acyl-TETA。用红外光谱和表面孔径吸附仪对树脂进行表征, 并用于对硝基酚(PNP)的吸附研究。静态和动态吸附实验结果表明, 两种树脂对PNP的吸附过程都可以用准二级动力学方程来描述;液膜扩散为吸附PNP的主要控制步骤;吸附符合Freundlich等温方程, 为多分子层吸附;吸附为自发的放热过程, 属于以物理吸附为主的吸附过程;PS-TETA与PS-Acyl-TETA对PNP的饱和吸附量分别为157.87mg/mL、90.77mg/mL, 穿透体积为165BV、80BV, 动态脱附率为98.4% 、98.9%。     

Polymer-based chelating adsorbents for the selective removal of boron from water and wastewater: A review

Boron removal from water is a highly interesting research area that has been addressed in various investigations in the recent years. This is due to the expansion of harmful effects of boron traces in water streams on the environment and human health with the rise in boron global demand in various industries that coincided with the implantation of more stringent water quality standards. Various technologies have been applied for the removal of boron from water solutions, including ion exchange technology, which has a great potential in treating varieties of boron-containing streams up to levels in parts per million using boron-selective adsorbents. This article comprehensively reviews the latest progress in the development of polymer-based boron-selective (chelating) materials and their applications for the removal of boron from water solutions, including commercial boron-selective resins (BSRs) and their researched counterparts. The emerging trends in the development of alternative adsorbents with different substrates, morphologies, and functional groups are also elucidated. The future directions to overcome the limitations of the present generation of resins are also discussed.     

离子改性Y分子筛吸附分离1,1,1,2-四氟乙烷/1,1-二氟-2-氯乙烯

用CaCl₂、La（NO₃）₃和Ce（NO₃） ₃溶液对NaY分子筛进行离子改性制备出CaY、LaY和CeY分子筛。将其及NaY为吸附剂,利用动态吸附法评价其吸附分离1,1,1,2-四氟乙烷（HFC-134a）产品中微量1,1-二氟-2-氯乙烯（HCFC-1122）的性能。同时采用X射线衍射（XRD）、吡啶红外（FTIR）和氨-程序升温脱附（NH₃-TPD）等手段对新鲜及再生后的吸附剂进行结构和表面性质表征。结果表明：CaY、LaY与CeY分子筛上的Brønsted酸中心可与HCFC-1122形成p-吸附配合物,从而将吸附流出气中HCFC-1122的残余率降低至1.0%以下;Brønsted酸强度越高,p-吸附配合物越容易形成,最低吸附温度越低（CeY     

Medicinal importance of grapefruit juice and its interaction with various drugs

Grapefruit juice is consumed widely in today's health conscious world as a protector against cardiovascular diseases and cancers. It has however, been found to be an inhibitor of the intestinal cytochrome P – 450 3A4 system, which is responsible for the first pass metabolism of many drugs. The P – glycoprotein pump, found in the brush border of the intestinal wall which transports many of these cytochrome P – 450 3A4 substrates, has also been implicated to be inhibited by grapefruit juice. By inhibiting these enzyme systems, grapefruit juice alters the pharmacokinetics of a variety of medications, leading to elevation of their serum concentrations. Most notable are its effects on the calcium channel antagonist and the statin group of drugs. In the case of many drugs, the increased serum concentration has been found to be associated with increased frequency of dose dependent adverse effects. In this review, we have discussed the phytochemistry of grapefruit juice, the various drugs involved in the drug – grapefruit juice eraction with their mechanisms of action and have presented the clinical implications of these interactions.