淀粉磷酸酯基高吸水树脂对Cu2+的等温吸附行为研究

含重金属离子废水的处理一直是人们关注的重点和难点.近年来,吸附法是处理重金属废水的一种比较有效的方法。本文以马铃薯淀粉磷酸酯为原料合成高吸水树脂,并且检测了高吸水树脂对Cu2+的静态等温吸附性能。讨论了不同丙烯酸中和度的高吸水树脂产品、Cu2+离子浓度、树脂用量和吸附时间对吸附容量的影响,并由X射线光电子能谱验证了铜离子在树脂上的吸附。     

巯基树脂对重金属离子的吸附性能

研究了自合成的巯基树脂对重金属离子Pb^2 、Cu^2 、Cd^2 ．Ni^2 、Co^2 的吸附容量、吸附动力学、等温吸附过程等静态吸附性能，同时研究了影响吸附的因素和吸附机理．结果表明，该树脂对软酸型重金属离子吸附容量高．pH=5．0-5．7，低温有利于吸附，树脂对各重金属离子等温吸附在实验浓度范围内均符合Langmuir和Freundnch方程．吸附机理研究表明，巯基与重金属离子发生了离子交换和配位反应，化学吸附起支配作用。     

麦麸对重金属离子的吸附性能研究

以麦麸为天然吸附剂,从水溶液中去除重金属离子.实验表明,麦麸对重金属离子有优良的吸附性能.在约10min内达到吸附平衡,吸附容量分别为:Hg2 70mg/g、Pb2 63mg/g、Cd2 21mg/g、Cu2 15mg/g、Ni2 13mg/g及Cr3 9.3mg/g;吸附速率很快,并且对上述金属离子有良好的选择性.     

羧基淀粉接枝聚合物对重金属离子的吸附速率方程

以Ｃｅ＾４＋为引发剂，将丙烯腈接枝到高交联淀粉上，接枝产物再经皂化水解制得水不溶性羧基淀粉接枝聚合物（简称羧基淀粉）。研究了羧基淀粉吸附重金属离子的动力学行为。实验结果表明，羧基淀粉吸附速率快，吸附平衡时间短，吸附量随时间的变化规律遵从Ｑ／Ｑ∞＝ａｔ（１＋ａｔ）方程。     

花生壳对水中重金属离子的吸附

本文探讨了花生壳对水中重金属离子的吸附特性,绘制出吸附等温线,并由Langmuir曲线求出吸附平衡常数b及饱和吸附量q_∞,由Freundlich式求出两个经验常数K和1/n。进行了处理花生壳与未处理花生壳及活性炭吸附性能的比较。又对氨水、抗坏血酸、EDTA等存在时花生壳对重金属离子吸附能力的影响进行了研究。在pH4.5～6.0时,于相同操作条件下,对欲测定的几种重金属离子分别进行6～8次实验,当离子浓度在0.4～1.6ppm范围内,其吸附率均在93.8％以上,相对标准偏差为0.67～2.37％。     

多胺型螯合树脂对重金属离子的吸附研究

研究了含有三乙烯四胺功能基的酚醛树脂（FQ—34）对Cu2 、Ni2 ,Zn2 、Co2 的静态吸附动力学、等温吸附等过程。结果表明，液膜扩散是吸附的主控步骤，可用G．E．Boyd膜扩散方程来描述；等温吸附属单分子层吸附，可用Langmuir等温方程描述。同时，还对吸附机理作了初步探讨。     

硫脲树脂的合成及其对金属离子的吸附性能

采用双(异硫氰酸甲酸)丁二酯分别与二乙烯三胺、三乙烯四胺、四乙烯五胺、多乙烯多胺单体进行加聚反应制得4种主链上含有硫脲基团的新型螯合树脂PETU-Ⅰ～PETU-Ⅳ。红外光谱分析表明,树脂中存在硫脲基团,树脂热稳定性和溶胀性能良好。用静态吸附法研究了PETU树脂对金属离子的吸附性能,4种树脂对Au(Ⅲ)的吸附容量分别为2.48、2.68、4.74和6.44mmol/g,对Ag(Ⅰ)的吸附容量分别为2.15、3.53、3.74和3.98mmol/g,对Cu(Ⅱ)、Zn(Ⅱ)等金属离子吸附容量低于0.36mmol/g;PETU-Ⅳ对Au-Cu和Au-Zn的分离因子>1000,PETU-Ⅱ对Ag-Cu和Ag-Zn的分离因子>10,说明树脂对Au(Ⅲ)、Ag(Ⅰ)具有较高的吸附容量和优良的吸附选择性。PETU-Ⅳ树脂重复使用5次,吸附容量无明显下降,说明树脂具有良好的重复利用性能。     

聚苯胺及其复合物对重金属离子的高效吸附性能

基于国外最新文献,系统总结了近年来聚苯胺及其复合物的制备方法及其重金属离子吸附性能,重点分析了吸附性能特征,指出聚苯胺及其复合物具有吸附下限浓度低、达到吸附平衡快以及解吸附性能优异等特点.填充有聚苯胺颗粒的吸附柱在动态处理初始浓度为83 ng/L的汞离子溶液时,经一次吸附与解吸循环操作后,汞离子的富集倍数可达120倍.应用于冷原子吸收光谱的待测样品的浓缩与富集,可以将汞的测试下限拓展到0.05 ng/L.聚苯胺及其复合物在痕量重金属离子的高效富集与灵敏探测等方面展示了广阔的应用前景.     

带羧基乳液浸渍纸对重金属离子的吸附性能研究

制备了带羧基乳液浸渍纸.讨论了该浸渍纸对静态水溶液中重金属的离子交换性能,以及温度和pH值对离子吸附量的影响,发现该浸渍纸在用于水处理中具有良好的吸附性能和再生性能.     

丙烯酸系高吸水树脂反相悬浮聚合法制备及其吸附性

采用反相悬浮聚合法制备了聚(丙烯酸/丙烯酰胺)(PAAM)、聚(丙烯酸/2-丙烯酰胺基-2-甲基丙磺酸)(PAAMPS)两种共聚高吸水树脂,并对两者的吸液吸附性能进行了比较.吸液成吸附初期,PAAM、PAAMPS在蒸馏水、NaCl等各种盐溶液中吸液倍率以及对金属离子溶液的吸附量随吸液或吸附时间的增加而迅速增加,约10 min达吸液、吸附平衡,且在各种盐溶液中的吸液倍率明显低于蒸馏水中的,PAAMPS的耐盐性比PAAM更好.高吸水树脂中AMPS代替AM后,对金属离子Cu2+、Cr3+的平衡吸附量几乎不变,但对Fe3+的平衡吸附量略有减小.PAAM较PAAMPS在CuCl2、FeCl3、CrCl3溶液中平衡吸液时间明显延长.     

Acrylamide–itaconic acid superabsorbent polymers and superabsorbent polymer/mica nanocomposites

Superabsorbent polymer acrylamide (AM)/itaconic acid (IA) and its nanocomposite were synthesized by redox polymerization in an aqueous solution of both monomers with mica used as an inorganic additive. The influences of IA concentration, mica content, and crosslinker concentration on the water absorption and physical properties of the superabsorbent polymer and its nanocomposite were examined. Water absorbency in artificial urine by the synthesized copolymers, and the gel strength of the superabsorbent copolymers and their nanocomposites, were tested with loads of 0.28 or 0.70 psi. Transmission electron micrographs and X‐ray diffraction confirmed that the polymer chains were successfully intercalated into the silicate layers in the mica. The water absorbency and the artificial urine absorbency of the composite with an AM‐to‐IA mole ratio of 95:5, 0.2% mol N‐MBA, and 5% w/w mica were 748 ± 5 and 76 ± 2 g g^?1, respectively, whilst the neat copolymer achieved only 640 ± 7 and 72 ± 2 g g^?1 in water and artificial urine, respectively. The viscoelastic behavior suggested that the swollen gel of the nanocomposites exhibited mechanical stability and elasticity. Copyright © 2009 John Wiley & Sons, Ltd.     

Preparation and properties of superabsorbent containing starch and sodium humate

Starch and sodium humate were utilized as raw material for synthesizing starch‐g‐poly(acrylic acid)/sodium humate (St‐g‐PAA/SH) superabsorbent by graft copolymerization reaction of starch (St) and acrylic acid (AA) in the presence of sodium humate (SH) in aqueous solution. The effect of weight ratio of AA to St, initial monomer concentration, neutralization degree of AA, amount of crosslinker, initiator and SH on water absorbency of the superabsorbent were studied. The swelling rate and swelling behavior in NaCl solution as well as reswelling ability of the superabsorbent were systematically investigated. The results showed that the superabsorbent synthesized under optimal conditions with SH content of 7.7 wt% and St content of 11.5 wt% exhibits water absorbency of 1100 g/g in distilled water and 86 g/g in 0.9 wt% NaCl solution, respectively. Introducing SH into the St‐g‐PAA polymeric network can improved the swelling rate and reswelling capability of the superabsorbent. Copyright © 2008 John Wiley & Sons, Ltd.     

Preparation,swelling behaviors and application of polyacrylamide/attapulgite superabsorbent composites

A series of superabsorbent composites, polyacrylamide/attapulgite (PAMA), were prepared from acrylamide (AM) and attapulgite micropowder in aqueous solution, using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator and then saponified with sodium hydroxide solution. This paper focuses on swelling behaviors of the PAMA superabsorbent composites in various saline solutions. The results indicate that saline solutions can weaken the swelling abilities of the PAMA compsites greatly. Water absorbency of the PAMA composites with 20 and 40 wt% attapulgite in aqueous chloride salt solutions has the following order: Li⁺ = Na⁺ = K⁺, Mg²⁺ > Ca²⁺ = Ba²⁺ all through the range of concentration investigated. However, swelling properties of the composites are complicated in CuCl_2(aq), AlCl_3(aq) and FeCl_3(aq) solutions and are related to saline solutions concentration. The deswelling behavior of PAMA composites is more obvious in univalent chloride salt solutions than in divalent and trivalent ones. The influence of kind and valence of anions on swelling ability of the composites is limited and almost the same. Moreover, reswelling capability, practical water retention ability in sand soil of the composites and the effect of pH on water absorbency of the PAMA composites were investigated. The PAMA composite shows good water retention and reswelling ability in sand soil, and may be used as a recyclable water‐managing material for the renewal of arid and desert environment. Copyright © 2006 John Wiley & Sons, Ltd.     

pH-Responsive Nanocomposites From Methylcellulose and Attapulgite Nanorods: Synthesis,Swelling and Absorption Performance on Heavy Metal Ions

A pH-responsive methylcellulose-g-poly(sodium acrylate)/attapulgite (MC-g-PNaA/APT) nanocomposite superabsorbent was prepared by the free-radical solution polymerization of methylcellulose (MC), sodium acrylate (NaA) and nanoscale attapulgite (APT) in the presence of the crosslinker N,N′-methylene-bis-acrylamide (MBA). The structure and morphology of the nanocomposite were characterized by FTIR, FESEM, TEM, XRD and EDS techniques, and the effects of the amount of MBA, MC and APT nanorods on swelling behaviors were also evaluated. Results indicate that NaA has been grafted onto MC macromolecular chains and APT nanorods participated in polymerization by its active silanol groups, and APT led to a better dispersion in the MC-g-PNaA matrix. The incorporation of APT clearly enhanced the swelling capacity and rate of the superabsorbent. In addition, the nanocomposite exhibited excellent absorption capacity on heavy metal ions, and its absorption amounts on Ni²⁺, Cu²⁺ and Zn²⁺ ions reached 9.86, 7.66 and 21.86 times greater than active carbon (AC). The biopolymer-based nanocomposite superabsorbents can be used as a potential water-saving material and candidate of AC for heavy metal ion absorption.     

淀粉基高吸水性树脂吸水性能的测定条件评价

研究了测定条件对淀粉基高吸水性树脂吸水性能的影响,分别考察了测定方法、树脂粒径、初始加水量、水介质pH、温度及溶液中盐的质量分数对树脂吸水倍率和吸水速率的影响.结果表明,采用100目网筛过滤法测定树脂的吸水性能结果较准确;当吸水介质与干树脂的质量比为2 400∶1,pH为7时,可以使树脂达到最大饱和吸水倍率;在树脂粒径96～180μm范围内,随着树脂粒径的减小、水介质温度的升高及盐浓度的降低,树脂的吸水倍率和吸水速率增大.     

一种重金属离子吸附捕集剂的合成及性能研究

在较温和的温度条件下合成了N,N-双(二硫代羧基)二乙烯三胺乙基聚合物,并对NaOH的加入次序及加入量、二硫化碳加入次序、二乙烯三胺的用量、反应温度、反应时间等进行了研究。论文通过红外光谱、紫外光谱和熔点测定对聚合物进行表征。研究了聚合物吸附捕集部分重金属离子的性能,结果表明,合成的聚合物能稳定地吸附捕集某些重金属离子,对Ag 、Cu2 、Zn2 等离子有较高的吸附量;吸附效果在pH值为5左右时最好。     

Synthesis of 2-mercaptobenzothiazole/magnetic nanoparticles modified multi-walled carbon nanotubes for simultaneous solid-phase microextraction of cadmium and lead

This study describes the successful sequential modification of multi-walled carbon nanotube (MWCNT) by Fe₃O₄ magnetic nanoparticles and 2-mercaptobenzothiazole (MBT) followed by its application as a novel sorbent for simultaneous magnetic solid phase microextraction of lead and cadmium. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to confirm the chemical surface modification of the MWCNT. The ions retained on the 2-MBT/magnetic nanoparticles modified MWCNTs were eluted with 1.0 mL of nitric acid (0.8 mol L^?1) in methanol solution and determined by the flame atomic absorption spectrometry. All parameters affecting the extraction condition were thoroughly investigated and optimised. Under the optimised condition preconcentration factor of 150.0, enhancement factors of 149.0 and 149.2 and limits of detection of 0.21 and 0.01 µg L^?1 were achieved for lead and cadmium, respectively. Using the prepared magnetic nanocomposite, the possible interference of other common ions associated with lead and cadmium determination was effectively avoided and the method was successfully applied to the simultaneous determination of the target ions in various environmental water samples.     

Synthesis of a slow‐release and superabsorbent nitrogen fertilizer and its properties

A slow‐release and superabsorbent nitrogen fertilizer (SSNF) was synthesized by aqueous solution copolymerization of acrylic acid and maleic anhydride using N,N′‐methylene bisacrylamide as a crosslinker, ammonium persulfate and sodium sulfite as an initiator in the presence of urea. The effects on water absorbency such as amount of crosslinker, initiator, urea and maleic acid, degree of neutralization, etc. were investigated. To improve slow release and water retention properties, the product was surface‐crosslinked with trihydroxymethyl propane glycidol ether (6360). The nitrogen content of the SSNF synthesized under optimal conditions was 28.5%, and the water absorbencies were about 900 (g/g) in distilled water and 180 (g/g) in tap water. The nitrogen slow release behavior of the SSNF in water and water retention capacity of the soil with SSNF were also investigated. The results showed that the surface‐crosslinked product not only had good slow release property but also excellent soil moisture preservation capacity, which could effectively improve the utilization of fertilizer and water resources simultaneously. The results of the present work indicated that the SSNF could be found an application in agriculture and horticulture, especially in drought‐prone areas where the availability of water is insufficient. Copyright © 2006 John Wiley & Sons, Ltd.