微波法羧甲基壳聚糖制备及其对Cu~(2+)吸附性能的研究

在微波辐射下,以壳聚糖为原料,研究了碱用量、氯乙酸用量、反应温度和微波加热时间四个因素对羧甲基壳聚糖制备的影响。并将其用于对废水中Cu2+的吸附,考察了不同pH,羧甲基壳聚糖的用量,振荡时间及溶液中Cu2+初始浓度对吸附性能的影响。结果表明最佳合成羧甲基壳聚糖的工艺条件为1.0g壳聚糖,6.0mL30%氢氧化钠溶液,1.4g氯乙酸,反应θ为50℃,微波加热t为20 min。当溶液pH为5.45,羧甲基壳聚糖投加量为0.03 g,振荡t为1.5 h,Cu2+初始质量浓度为300 mg/L时,在此条件下羧甲基壳聚糖对Cu2+溶液的吸附量为177.83mg/g。     

O-羧甲基壳聚糖对电镀废水中Cr(Ⅵ)吸附性能的研究

O-羧甲基壳聚糖对六价铬具有吸附作用.本文研究了溶液的pH、吸附时间、温度和O-羧甲基壳聚糖的加入量对其吸附性能的影响.结果表明,在室温下,pH为2,吸附时间2 h,O-羧甲基壳聚糖加入量为5 g时,其吸附性能最好,吸附率可达98%以上.     

O-羧甲基壳聚糖的制备及其对Ni^2＋吸附性能研究

通过羧烷基化对壳聚糖进行改性,发现当壳聚糖与氯乙酸、壳聚糖与氢氧化钾的质量比分别为1:4.26及2:2.3时,45℃下反应4.5h,可得到O-羧甲基壳聚糖,产率为97.1%,对产品进行红外光谱表征.在此基础上研究了制备的O-羧甲基壳聚糖对Ni2+的吸附性,探讨溶液pH、Ni2+初始浓度和取代度等因素对其吸附性的影响.结果表明,最佳吸附条件是溶液pH为8.0、Ni2+初始浓度为33.2778 mg·mL-1、O-羧甲基壳聚糖取代度为0.712、平衡吸附时间为6 h.对O-羧甲基壳聚糖进行脱附研究,结果显示H2SO4是一种很好的脱附剂,能在0.5h内将吸附在O-羧甲基壳聚糖上的Ni2+脱去90%以上,重现性好.     

交联羧甲基壳聚糖对铅离子的吸附性能研究

主要对交联羧甲基壳聚糖对Pb^2 的吸附作用进行了研究，探讨了交联度，反应时间，溶液的PH值，温度，Pb^2＋的初始浓度等因素对吸附性能的影响。实验结果表明，交联羧甲基壳聚糖在水溶液中不流失。对Pb^2 的吸附具有Langmuir的吸附特征，有附过程符合一级反应动力学过程，低温有利于吸附，当溶液PH值为5－6时，吸附性能最好，最大吸附量为230mg/g。EDTA是理想的脱附剂，洗脱后的树脂可重复作用。     

交联壳聚糖对废水中Cu2+的吸附性能

以壳聚糖为原料制备交联壳聚糖吸附剂,并将其用于吸附废水中的Cu2+,考察了交联剂的用量、溶液中Cu2+初始浓度、pH、温度和时间等对交联壳聚糖吸附性能的影响。结果表明,壳聚糖与交联剂的用量比为m(壳聚糖)∶V(甲醛)∶V(戊二醛)=1.5g∶6mL∶4.5mL、溶液pH为6,溶液中Cu2+初始浓度为5mmol/L时吸附效果最佳,且吸附量随着温度升高而增加,吸附表现为吸热过程。     

羧甲基壳聚糖微球对曙红Y的吸附研究

以壳聚糖粉末为原料,戊二醛进行交联、羧甲基化,制得羧甲基壳聚糖微球。采用SEM对壳聚糖微球的形貌、大小进行了表征,研究羧甲基壳聚糖微球对曙红Y的吸附性能。探讨吸附剂用量、吸附时间、曙红Y的初始浓度、pH、温度对脱色率的影响,研究吸附等温曲线和动力学方程。实验结果表明,曙红Y初始浓度增加时,吸附量也增加,直到吸附饱和,羧甲基壳聚糖的饱和吸附量为75 mg/g;相同条件下,吸附剂用量增加时,平衡吸附量减小,去除率增加。298 K,吸附剂投加量为1 g,pH=7.0,吸附时间为40 min时,初始浓度为560 mg/L的曙红Y染料的去除率可以达到90%以上。符合Langmuir等温方程和二级吸附动力学方程。     

N-羧甲基壳聚糖吸附锰矿废水中锰离子(Ⅱ)研究

利用N-羧甲基壳聚糖吸附锰矿废水中Mn2+,通过考察吸附剂质量浓度、溶液pH、吸附温度及时间的影响,采用L16(45)正交试验确定吸附10.6 mg/L Mn2+废水的最佳工艺条件为:30.0 mg/m L N-羧甲基壳聚糖,在溶液pH=5.5、65℃下,振摇吸附8.5 h,Mn2+去除率99.1%,吸附后废水中Mn2+浓度0.095 mg/L,满足国家规定地表水锰含量要求,吸附过程符合Langmiur吸附特征,属于单分子层吸附。由于N-羧甲基壳聚糖吸附锰矿废水中Mn2+工艺简便、吸附效率高,从而可为相关行业的水污染处理提供理论基础。     

壳聚糖对高锰地下水的吸附研究

对壳聚糖吸附高锰地下水进行了研究,考察了吸附剂用量、时间、温度、pH值对壳聚糖吸附性能的影响。结果表明,对含1 mg/L的高锰地下水,吸附条件为:温度40℃,壳聚糖量0.8 g,时间8 h,pH为10时,壳聚糖对其的吸附率为98.78%;壳聚糖对Mn2+的吸附具有Langmu ir吸附特征,分子中的氨基与Mn2+发生了配位作用,吸附机理以单分子层化学吸附为主,吸附量受温度影响不大。     

羧甲基壳聚糖对Fe2+的络合及光谱分析

本文研究羧甲基壳聚糖对Fe^2＋的吸附性能,探讨了时间、PH值等对吸附性质的影响.PH=6时羧甲基壳聚糖对Fe^2＋最大吸附量为0.7mmol/g.并通过IR和UV光谱证实了羧甲基壳聚糖对Fe^2＋的络合作用.     

纤维素/壳聚糖复合微球的制备及对铜(Ⅱ)的吸附性能研究

采用纤维素与壳聚糖复合的方法,以戊二醛为交联剂制备了一种具有Cu2+印迹的纤维素/壳聚糖复合微球,考察了制备过程中纤维素种类,纤维素与壳聚糖质量比、戊二醛用量、交联时间、交联温度及溶液pH对吸附铜(Ⅱ)的影响,并用扫描电镜(SEM)和傅里叶红外光谱(FTIR)对复合微球进行表征.结果表明,当壳聚糖与羧甲基纤维素质量比为...     

羧甲基壳聚糖对稀土离子吸附性能的研究

以壳聚糖为原料,在碱性条件下合成了标题化合物,考察了其对稀土离子La3+、Nd3+、Sm3+的吸附性能.讨论了时间、溶液的酸度、初始离子浓度、羧甲基取代度对吸附性能的影响.发现羧甲基壳聚糖对稀土离子有较强的吸附性,吸附性满足Langmuir等温式.     

交联羧甲基壳聚糖树脂对稀土离子吸附性能研究

以羧甲基壳聚糖为原料，经戊二醛交联制备阳离子型树脂，考察了其对稀土离子La^3 、Nd^3 、Sm^3 、Lu^3 吸附性能。探讨了溶液的酸度、体系温度、初始离子浓度及离子强度对该树脂吸附性能的影响；发现羧甲基壳聚糖经戊二醛交联制成的树脂对稀土离子有较强的吸附性，最高吸附率可达99％以上，并且具有良好的重复使用性；其吸附性为满足Langmuir或Freumdilich等温式。     

Adsorption of Cu(II) ions from an aqueous solution by crosslinked amphoteric starch

The adsorption process of Cu(II) ions from aqueous solutions by crosslinked amphoteric starch with quaternary ammonium and carboxymethyl groups was investigated. The adsorption capacity was found to be dependent on the solution pH, the dose of the crosslinked amphoteric starch, and the initial concentration of Cu(II) ions. Moreover, the adsorption capacity increased with an increasing degree of substitution (DS) of the carboxymethyl groups. The adsorption followed a Freundlich adsorption isotherm. The adsorption process was endothermic, and the thermodynamic parameters were calculated at different DS values. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 728–732, 2004     

新型改性壳聚糖的制备及其对2,4-二氯苯酚的吸附

采用水杨醛与壳聚糖反应生成Schiff’s碱,再用NaBH4还原,环氧氯丙烷交联制备壳聚糖衍生物,用FTIR对改性壳聚糖进行表征,并用于2,4-二氯苯酚的吸附研究。测试了改性产物的溶解性能,考察了吸附时间、溶液pH值、酚的浓度以及改性剂用量等因素对氯酚吸附的影响。结果表明,水杨醛改性环氧氯丙烷交联壳聚糖不溶于水、酸和碱;在pH=7、吸附时间为2 h时,对2,4-二氯酚的吸附量为128.2 mg/g。     

Cu2+ removal from aqueous solution by modified chitosan hydrogels

BACKGROUND: The adsorption of Cu²⁺ from aqueous solution using crosslinked chitosan hydrogels impregnated with Congo Red (CR) by ion‐imprint technology was systematically investigated with particular reference to the effects of contact time, pH, and initial concentration on adsorption. RESULTS: The adsorption capacity of the crosslinked chitosan without impregnation was only 68.68 mg g^?1 for Cu²⁺. However, the adsorption capacity increased from 77.42 (without imprint ion) to 84.54 mg g^?1 (imprint ion content 0.5 mmol) after the chitosan was impregnated with a ratio of 1/12 of CR to chitosan. The as‐prepared adsorbents were found to be pH‐dependent and the process of adsorption agreed well with the Freundlich isotherm. The loaded adsorbents could be regenerated and reused without the appreciable loss of capacity. CONCLUSION: Chitosan hydrogels impregnated with CR showed higher Cu²⁺ adsorption capacities compared with those prepared conventionally without imprint ion, and thus developed a good approach to increase Cu²⁺ adsorption efficiency in the treatment of waste‐water. Copyright © 2012 Society of Chemical Industry     

The Development of Filter Media Using Plant and Marine Waste for Virus Removal from Drinking Water

Abstract:

Two natural wastes, palm leaves and shrimp shells, were purified and tested for their efficiency in adsorbing enteroviruses from drinking water. The chemical modification of marine waste was evaluated to prepare carboxymethyl chitin, while O-carboxymethyl chitosan was prepared by deacetylation of the carboxymethyl chitin to improve the adsorption of viruses from drinking water. The role of the reaction parameters such as temperature, time, concentration of alkali and etherified agent, and the material-to-liquor ratio were examined. Also, the effect of pH on the adsorption efficiency of enteroviruses in modified waste was evaluated. The results showed that raw palm leaves and O-carboxymethyl chitosan prepared as filter matrix exhibited a better adsorption efficiency in a wide range of pH levels. They can be used to adsorb viruses directly from tap water at ambient pH values without having multivalent-containing salts or adjusting the pH of tap water.     

Adsorption of guanosine,cytidine, and uridine on a β‐cyclodextrin derivative grafted chitosan

A β‐cyclodextrin derivative grafted chitosan (CDD‐C) was synthesized with chitosan and carboxymethyl‐β‐cyclodextrin (β‐CD). Its structure was characterized by elemental, infrared spectra, and X‐ray diffraction analyses. The degree of substitution by the carboxymethyl‐β‐CD moiety achieved 0.27 with the addition of DMF to the reaction solution. The results are in agreement with the expectations. The static adsorption properties for guanosine, cytidine, and uridine were studied. Experimental results demonstrated that CDD‐C had higher adsorption capability for guanosine than cytidine and uridine, and the adsorption capacity for guanosine was 74.20 mg/g. The adsorption capacity was greatly influenced by pH, time, and temperature. The introduction of chitosan enhanced the adsorption ability and adsorption selectivity of β‐CD for guanosine. This novel derivative of chitosan is expected to have wide applications in separation, concentration, and analysis of guanosine, cytidine, and uridine in biological sample. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3050–3055, 2007     

羧甲基壳聚糖净化海水的试验研究

用改性壳聚糖(羧甲基壳聚糖)作絮凝剂在室温(25℃)下对海水进行絮凝处理,研究了絮凝剂投加量、pH值和搅拌条件对絮凝处理效果的影响,并确定了适宜的操作条件:絮凝剂投加量范围为25～30mg/L,pH值范围为5～7,快速搅拌转速400r/min,时间90s,慢速搅拌转速60r/min,时间20min。在优化絮凝条件下浊度、化学耗氧量(CODMn)和总磷(TP)的去除率分别达72.6%、53.9%和40.0%。将羧甲基壳聚糖与壳聚糖对海水的絮凝净化效果进行了对比分析,结果表明,羧甲基壳聚糖对海水的絮凝效果相对壳聚糖有了较大提高,浊度和CODMn去除率明显提高,投加量适用范围更宽。     

胺化羧甲基改性磁性壳聚糖的制备及吸附性能研究

采用交联法制备了磁性壳聚糖,并在此基础上使用柠檬酸及二乙烯三胺对其进行化学改性,得到了磁性能良好、颗粒分布均匀、平均孔径为4.37 nm的胺化羧甲基改性磁性壳聚糖。将其用于模拟废水中进行静态吸附实验。结果表明,改性后的磁性壳聚糖在保证机械强度与回收率的基础上,提高了磁性壳聚糖的吸附性能,在最适pH=6的条件下,对Cu~(2+)、Cd~(2+)、Ni~(2+)的吸附容量分别达到76.82、54.15、62.64 mg/g。     

TOCNF与磁性羧甲基壳聚糖纳米粒子复合物的制备及吸附Pb2+的特性

水体中铅污染对环境及人的健康安全造成了极大的危害。本文将四甲基呱啶（TEMPO）氧化的纤维素纳米纤维（TEMPO-oxidized cellulose nanofibers,TOCNF）与磁性羧甲基壳聚糖纳米粒子（magnetic carboxymethyl chitosan nanoparticles,MCCN）交联复合制备一种经济高效且对环境无毒害的Pb²⁺吸附剂,对复合前后的材料进行结构表征。通过单因素实验研究pH、Pb²⁺初始浓度、吸附时间及温度对Pb²⁺吸附效率的影响,确定最优吸附条件后比较TOCNF/MCCN及TOCNF对Pb²⁺的吸附效果,研究复合材料对Pb²⁺的吸附特性。研究结果表明,Fe₃O₄成功被羧甲基壳聚糖纳米粒子包裹并与TOCNF交联复合,在最优吸附条件（pH=5,Pb²⁺初始浓度为100mg/L,吸附时间为240min,常温下进行实验）下,TOCNF/MCCN吸附Pb²⁺的饱和容量为193.5mg/g,比TOCNF高了近一倍。复合吸附剂吸附Pb²⁺的过程更符合准二级动力学方程,说明决定吸附速率的主要是化学吸附。等温吸附方程的相关系数R²表明,Langmuir方程能更好地拟合吸附过程,说明复合吸附剂对Pb²⁺的吸附主要是表面基团的单分子层吸附。通过线性方程的斜率计算得到的理论饱和吸附量为201.1mg/g,与实际值差3.8%,经过5次解吸再吸附的过程,吸附剂的吸附效率仅下降了13%,表明该吸附剂有良好的可再生性,具有很好的应用前景。