球形木素基离子交换树脂的合成及其对Cr~(3+)的吸附特性

以木素磺酸钙为原料,利用反相悬浮聚合技术在一种价廉无毒的介质相中制备出球状木质素基离子交换树脂,并讨论了它对Cr3+的吸附性能。结果表明,树脂对低浓度Cr3+的吸附效果好,前期吸附速度快,40min后吸附速率趋缓;升高温度能明显提高前期吸附速率,饱和吸附量约为60mgCr3+/g干树脂,而且树脂在较宽的弱酸性范围内表现出良好的吸附性能。     

不同类型阴离子交换树脂对Cr(Ⅵ)的吸附性能研究

通过静态吸附实验、动力学实验,从3种吸附去除Cr(Ⅵ)的离子交换树脂中优选出DEX-Cr树脂,研究了pH、温度对其交换性能的影响,进一步对树脂的动态吸附-再生性能和重复使用稳定性进行了考察。结果表明DEX-Cr树脂对Cr(Ⅵ)的吸附去除效果好,且重复使用稳定性高,可以作为分离去除Cr(Ⅵ)的高效吸附剂。     

D301和MIEX两种阴离子交换树脂对水中BrO3-的吸附性能

研究了D301和MIEX两种阴离子交换树脂对水中BrO_3~-的吸附性能。结果表明:pH值对两种树脂吸附BrO_3~-的影响相似,两种树脂均在pH为4～9范围时对BrO_3~-的吸附量最大。共存Cl~-、SO_4~(2-)和NO~-_3明显削弱两种树脂对BrO_3~-的吸附,其影响大小顺序为NO~-_3SO_4~(2-)Cl~-。MIEX树脂吸附BrO_3~-仅需4 min达到平衡,D301树脂吸附BrO_3~-需180 min达到平衡,MIEX树脂具有比D301树脂更大的准二级速率常数K_2和颗粒内扩散速率常数K_(id)。BrO_3~-在D301和MIEX两种树脂上的吸附等温线符合Freundlich方程,MIEX树脂对BrO_3~-的吸附量大于D301树脂对BrO_3~-的吸附量。D301和MIEX两种树脂对BrO_3~-的吸附机理为阴离子交换。     

酸性吸附树脂对2,6-二氯苯酚的吸附热力学和动力学研究

本文以二硫代二苯甲酸、均苯四甲酸酐和没食子酸为修饰剂,通过后交联反应和化学修饰反应制备了3种酸性功能基修饰的超高交联树脂。通过等温吸附实验和吸附动力学实验,探讨了3种酸性吸附树脂对2,6-二氯苯酚(2,6-DCP)的吸附性能和吸附机制。结果表明,3种酸性吸附树脂对2,6-DCP均具有良好的吸附性能,吸附量随着2,6-DCP初始浓度的增大而增加,随着温度的升高而减小。Langmuir和Freundlich等温吸附方程均能够较好地拟合吸附等温线,3种酸性树脂对2,6-DCP的吸附机理较复杂。吸附热力学结果表明,吸附过程主要为放热、自发的物理吸附过程。3种酸性树脂对2,6-DCP的吸附动力学过程符合准一级动力学方程,颗粒内扩散是该吸附过程的主要控制步骤。3种酸性吸附树脂对2,6-DCP的吸附速率常数大小顺序为kGAMRkDSTAMRkPMDAMR。     

大孔吸附树脂对肿瘤坏死因子吸附性能的研究

选用NK-110、碳化树脂和MET-10043种大孔吸附树脂,通过对树脂吸附量的测定,吸附动力学曲线和吸附等温线的描述等方法,研究了3种大孔吸附树脂对血浆中TNFα的吸附性能,结果表明NK-110和MET-1004对TNFα的吸附量较高,其中又以MET-1004的吸附速率最快     

大孔吸附树脂分离纯化金银花中黄酮类物质的研究

比较了AB-8、S-8、NKA-9和D-101 4种大孔吸附树脂对金银花提取液中黄酮类物质的吸附及解吸附性能.在静态吸附试验基础上,筛选出效果较好的D-101树脂进行动态试验研究,结果表明,D-101树脂在30℃下对金银花黄酮类物质的静态吸附-动态解吸较优的工艺参数为:上样液pH值2.46,解吸液为95%乙醇,解吸液的流速为3mL/min,pH值11,4.5BV解吸液即可完全洗脱被树脂吸附的黄酮类物质,其解吸率高达98.00%.在试验研究范围内,树脂吸附金银花黄酮是自发性放热过程,并且符合Langmuir方程,此外树脂对黄酮的吸附动力学可用Pseudo-second-order模型较好地拟合,其表观吸附速率常数为Kso℃=3.43×10-2g/(mg·min).     

大孔树脂对中分子物质的吸附研究 Ⅱ.对尿毒症患者血浆中分子物质的吸附性能

前文~1已从14种树脂中筛选出对中分子物质具有较好吸附性能的X_3大孔吸附树脂。本文则在此基础上,详细研究了X_3树脂对尿毒症患者血浆中分子物质的吸附性能及其血液相容性。     

巯基树脂对金属离子的吸附性能(Ⅱ)

研究了自合成的巯基树脂对重金属离子Ag 、Hg2 、Cr3 的吸附容量、吸附动力学、等温吸附过程等静态吸附性能,影响吸附的因素和吸附机理.结果表明,该树脂对上述3种离子吸附能力强,吸附量分别达6.56mmol/g、3.25mmol/g、2.10mmol/g.树脂对各重金属离子等温吸附在实验浓度范围内符合Langmuir或Freundlich方程.吸附机理研究表明,巯基与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;另外树脂对Ag 、Hg2 吸附过程中存在一定的氧化还原现象.     

胺基酚醛型吸附树脂对染料废水的吸附与脱色

研究了胺基酚醛型吸附树脂对4种水溶性染料酸性橙II,活性红R-3B、活性黑KN-B、活性翠蓝KN-G的吸附性能。探讨了浓度、温度等因素对染料吸附性能的影响。结果表明,吸附树脂对酸性橙II具有较好的吸附;升高温度有利于吸附;随染料浓度的增大,树脂的吸附量增加。吸附树脂对4种水溶性染料的吸附速率较快,达到吸附平衡所用时间较短。对模拟废水的脱色率均达到了95.7%以上。     

SH15树脂吸附胞二磷胆碱的热力学及动力学研究

静态条件下,研究了SH15树脂吸附水溶液中胞二磷胆碱(CDPC)的热力学和动力学特性.测定了不同温度下,热力学性质的变化.实验结果表明,SH15树脂对CDPC吸附平衡数据符合Langmmuir吸附等温方程,吸附过程为自发的物理吸附过程.考察了温度、溶液浓度、树脂粒径和搅拌速率对吸附过程的影响.运用动边界模型(MBM)描述了SH15树脂吸附CDPC的动力学过程,确定在实验条件范围内,SH15树脂吸附CDPC的吸附速度受颗粒扩散控制,并计算出吸附过程的表观活化能为9.73kJ/mol,反应级数为0.47,速率常数为0.0744,并推导出CDPC:在SH15树脂上的动力学总方程.     

Speciation of Cr(III) and Cr(VI) in Environmental Samples after Solid Phase Extraction on Amberlite XAD–2000

A method for speciation of Cr(III) and Cr(VI) in real samples has been developed. Cr(VI) has been separated from Cr(III) and preconcentrated as its pyrrolidinedithiocarbamate (APDC) complex by using a column containing Amberlite XAD–2000 resin and determined by FAAS. Total chromium has also been determined by FAAS after conversion of Cr(III) to Cr(VI) by oxidation with KMnO₄. Cr(III) has been calculated by subtracting Cr(VI) from the total. The effect of pH, flow‐rate, adsorption and batch capacity and effect of various metal cations and salt anions on the sorption onto the resin were investigated. The adsorption is quantitative in the pH range of 1.5–2.5, and Cr(VI) ion was desorbed by using H₂SO₄ in acetone. The recovery of Cr(VI) was 97 ± 4 at a 95% confidence level. The highest preconcentration factor was 80 for a 200 mL sample volume. The adsorption and batch capacity of sorbent were 7.4 and 8.0 mg g^?1 Cr(VI), respectively, and loading half time was 5.0 min. The detection limit of Cr(VI) is 0.6 μg/L. The procedure has been applied to the determination and speciation of chromium in stream water, tap water, mineral spring water and spring water. Also, the proposed method was applied to total chromium preconcentration in microwave digested moss and rock samples with satisfactory results. The developed method was validated with CRM‐TMDW‐500 (Certified Reference Material Trace Metals in Drinking Water) and BCR‐CRM 144R s (Certified Reference Material Sewage Sludge, Domestic Origin) and the results obtained were in good agreement with the certified values. The relative standard deviations were below 6%.     

季铵功能化的金属有机骨架对水中双氯芬酸钠的高效吸附与去除

通过两步合成法制备了季铵功能化的金属有机骨架MIL-101（Cr）即MIL-101（Cr）-NMe₃,并考察了该材料对双氯芬酸钠（DCF）的吸附行为。通过不同浓度的DCF在MIL-101（Cr）-NMe₃吸附剂上的动力学数据,以及在不同温度下的吸附平衡等温线和MIL-101（Cr）-NMe₃吸附剂的重复使用性能考察,发现该材料对DCF的吸附过程符合准二级动力学方程,吸附平衡等温线符合Langmuir等温吸附模型,在20℃下的最大吸附量为310.6 mg/g,5次循环使用后吸附量未明显减少。MIL-101（Cr）-NMe₃对DCF的吸附作用机理可归结为静电相互作用和π-π相互作用,吸附效果远大于未修饰氨基的MIL-101（Cr）。可以预见该材料对水中DCF的去除具有良好的应用前景。     

同时吸附油和六价铬离子复合材料的制备及性能

以亲油疏水型三元乙丙橡胶(EPDM)作为基体, 焙烧Fe2O3和阴离子交换树脂201Х7作为填料, 利用熔融共混的方法, 制备一种可以同时吸附油和六价铬离子的用于污水处理的复合材料, 这种材料能够悬浮于油水界面处. 当焙烧Fe2O3和阴离子交换树脂的用量比例不同时, 材料吸附性能变化很大. 实验结果表明, 在保证复合材料密度介于油水密度之间的前提下, 随着焙烧Fe2O3含量的增加, 材料的吸油性能不断增大; 随着阴离子交换树脂含量的增加, 材料对六价铬的吸附性能不断增加. 在油水共存体系中, 复合材料对两种污染物的吸附率同时达到最佳时, 两种填料的比例可以确定, 因油品的不同而不同. 在油水共存体系中, 复合材料对油和六价铬的总吸附能力要远大于复合材料分别在单一吸附介质中的吸附能力.     

Characteristic and mechanism of Cr(Ⅵ) adsorption by ammonium sulfamate-bacterial cellulose in aqueous solutions

A new adsorbent, ammonium sulfamate-bacterial cellulose (ASBC), was prepared through chemical modifications of bacterial cellulose. The process of adsorbing Cr(Ⅵ) including its isotherm and kinetics, was measured and studied. The results showed that pH value was a very important parameter to the adsorbing efficiency. The adsorption kinetics can be described by a pseudo-second rate model and a particle diffusion equation. Both physical and chemical adsorptions existed in the adsorption process, but chemical adsorption was more dominatant. And particles internal diffusion was not the only rate controlling step. The adsorption equilibrium can be described by the Langmuir type, which indicated that a typical single-molecule layer adsorption of Cr(Ⅵ) by ASBC could be described. And the rate of adsorption followed the Slips model well, which indicated that ASBC had some multiphase and asymmetry. The coordination adsorption and ion exchange effect were the main mechanisms of chemical adsorption. The absorbed Cr(Ⅵ) can be desorbed effectively by 0.5 mol/L EDTA or HCl from the adsorbent, which could make it be reusable.     

Layer-by-layer self-assembly polytungstogermanate multilayer films and their photocatalytic properties under sunlight irradiation

Seven different types of thio- and/or amine-modified cellulose resin materials were synthesized and their mercury (II) ion adsorption properties determined. All seven resins showed good mercury (II) adsorption capability in the more neutral pH regions. However, the o-benzenedithiol- and o-aminothiophenol-modified cellulosic resins were found to be very effective in removing mercury (II) ions from strongly acidic media. For example, 93.5-100% mercury (II) ion recoveries from very acid aqueous solutions (nitric acid concentration ranged from 0.1 to 2.0 mol/L) were obtained using the o-benzenedithiol-modified resin while recoveries ranged from ca. 50% to 60% for the o-aminothiophenol-modified resin. An adsorption capacity of 23 mg (as Hg atoms) per gram of resin was observed for the o-benzenedithiol-modified cellulose in the presence of 1.0 mol/L nitric acid. This same resin shows very good selectivity for mercury (II) as only ruthenium (II) also somewhat adsorbed onto it out of 14 other metal ions studied (Ag(+), Al(3+), As(3+), Co(2+), Cd(2+), Cr(3+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pt(2+), Pb(2+), Ru(2+), and Zn(2+)).     

Speciation of Cr(III) and Cr(VI) in water after preconcentration of its 1,5-diphenylcarbazone complex on amberlite XAD-16 resin and determination by FAAS

A simple and sensitive method for the speciation, separation and preconcentration of Cr(VI) and Cr(III) in tap water was developed. Cr(VI) has been separated from Cr(III) and preconcentrated as its 1,5-diphenylcarbazone complex by using a column containing Amberlite XAD-16 resin and determined by FAAS. Total chromium has also been determined by FAAS after conversion of Cr(III) to Cr(VI) by oxidation with KMnO₄. Then, Cr(III) has been calculated by subtracting Cr(VI) from the total. The effect of acidity, amount of adsorbent, eluent type and flow rate of the sample solution on to the preconcentration procedure has been investigated. The retained Cr(VI) complex was eluated with 10 ml of 0.05 mol l⁻¹ H₂SO₄ solution in methanol. The recovery of Cr(VI) was 99.7±0.7 at 95% confidence level. The highest preconcentration factor was 25 for a 250 ml sample volume. The detection limit of Cr(VI) was found as 45 μg l⁻¹. The adsorption capacity of the resin was found as 0.4 mg g⁻¹ for Cr (VI). The effect of interfering ions has also been studied. The proposed method was applied to tap water samples and chromium species have been determined with the relative error <3%.     

新型酰乙基葡甲胺树脂的合成及吸硼性能

采用一步法, 用氯乙酰化聚苯乙烯树脂(PS-Acyl-Cl)与葡甲胺反应制得一种同时含有α-酰乙基胺和邻羟基双官能团的新型酰乙基葡甲胺树脂, 考察了溶液pH值、 温度、 初始浓度和吸附时间对酰乙基葡甲胺树脂吸附硼的影响. 结果表明, 在实验浓度范围内, 该树脂对硼的吸附符合Langmuir方程, 最大吸附量约为28.1 mg/g干树脂, 优于氯甲基树脂制得的硼特效树脂. 表明α-酰乙基胺和邻羟基双官能团对硼有双重或协同吸附作用. 该树脂在pH=6.0时对硼的吸附量最大; 温度对树脂吸附的影响不大; 树脂解吸率大于96%; 树脂重复使用5次后吸附量基本不变. 动力学研究结果表明, 吸附过程为液膜扩散控制过程.     

单宁微球对Cr（Ⅵ）的吸附性能

利用单宁微球吸附Cr（Ⅵ）,探讨了温度、pH值、Cr（Ⅵ）初始质量浓度等因素对单宁微球吸附性能的影响,并分析了其吸附等温曲线。结果表明,单宁微球对Cr（Ⅵ）具有很好的吸附效果,吸附量可达到45.5 mg/g。单宁微球对Cr（Ⅵ）的去除率随吸附时间的延长而增大,5 h后基本达到平衡。温度对单宁微球吸附Cr（Ⅵ）的影响比较...