细菌纤维素对重金属离子的吸附机理研究

以细菌纤维素(BC)为吸附剂,对重金属离子Cu2+,Pb2+和Cd2+的吸附等温线和吸附动力学特性进行了研究,并采用红外光谱分析法探讨了吸附作用机理。结果表明:BC对Cu2+,Pb2+和Cd2+吸附更好地符合Langmuir吸附等温方程和准二级反应动力学模型,说明吸附过程为单分子层吸附,化学吸附作用为主。粒子内扩散拟合曲线均不经过原点,证明粒子内扩散并不是唯一速率控制步骤。FT-IR分析表明吸附金属离子后的BC中—OH最大吸收位发生不同程度的蓝移,说明BC中部分—OH参与吸附,即与重金属离子之间发生反应,从而使—OH的数量减少。     

壳聚糖/纤维素复合微球对Cu2+的吸附

制备壳聚糖/纤维素(CS/CE)和交联壳聚糖/纤维素(ECS/CE)复合微球,用于吸附重金属离子,考察了微球对Cu2+的吸附性能。溶解性测试表明交联反应可提高微球在酸性介质中的化学稳定性。静态吸附表明,CS/CE和ECS/CE均能有效吸附Cu2+,pH 6附近吸附容量最大。吸附等温线与Langmuir和Freundlich模型均吻合,由Lang-muir模型得到的Cu2+饱和吸附容量分别为38.76 mg/g(CS/CE)和34.13 mg/g(ECS/CE)。CS/CE和ECS/CE对Cu2+的吸附初期为内扩散控制,但后期为配合反应控制。FTIR和X-射线光电子能谱(XPS)分析表明,壳聚糖中的N为Cu2+的主要吸附位,发生表面配合吸附。     

小麦秸秆纤维素球的改性

对自制的环氧小麦秸秆纤维素球进行改性,制备了两种改性小麦秸秆纤维素球。用正交设计法设计实验方案,探讨了其制备的优化实验条件。实验结果表明:当三乙胺盐酸盐溶液体积为4 mL、无水碳酸钠的用量为0.6 g、溶剂为30%乙醇溶液、反应时间为6 h时,制得的三乙胺盐酸盐改性小麦秸秆纤维素球(WS-MB-TEAHC)对Cu2+的吸附容量最大;当乙二胺盐酸盐溶液体积为8 mL、无水碳酸钠的用量为0.6 g、溶剂为30%二氧六环、反应时间为6 h时,制得的乙二胺盐酸盐改性小麦秸秆纤维素球(WS-MB-EDADHC)对Cu2+的吸附容量最大。红外光谱表征显示:环氧小麦秸秆纤维素球的环氧基参与了反应,改性后引入了含N官能团。     

柠檬酸改性柚子皮纤维素对废水中铜离子的吸附

采用静态平衡吸附法用柠檬酸纤维素(Cell-CA)吸附废水中Cu2+,考察了溶液的初始浓度、吸附剂颗粒大小、pH值、吸附时间和温度对吸附的影响,分析了吸附过程的热力学、动力学和等温吸附规律.结果表明,在pH值为5.5时Cell-CA对废水中Cu2+的吸附率为92.7%,吸附容量高达18.54mg/g;对不同温度下的吸附等温线采用Freundlich和Langmuir方程进行拟合,结果显示Langmuir方程的拟合效果更好.模拟吸附动力学实验数据符合准一级和准二级动力学模型,Cell-CA对Cu2+的吸附是放热反应.     

乙二胺螯合细菌纤维素的制备及其吸附Cu~(2+)研究

以细菌纤维素为原料制备乙二胺螯合细菌纤维素.通过红外光谱仪、元素分析仪对产物进行了表征.研究了乙二胺螯合细菌纤维素对铜离子的吸附动力学、等温吸附等特征.结果表明,吸附动力学可用拟二级速度方程来描述,吸附平衡符合Freundlich等温吸附方程,并对其吸附与解吸性能进行了分析.     

废烟梗制备纤维素黄原酸酯及其吸附Cu2+研究

以废烟梗为原料,制备纤维素黄原酸酯,并将其用于吸附去除水中的Cu2 。实验结果表明,烟梗碱化的NaOH浓度、CS2的加入量、CS2的反应时间、MgCl2的浓度等4个因素对纤维素黄原酸酯去除Cu2 的性能影响较大。通过4因素3水平L9(34)的正交实验设计,得到废烟梗纤维素黄原酸酯的最佳制备条件:NaOH浓度为15%,CS2加入量为0.4mL,CS2反应时间为3.0h,1%MgCl2的加入量为25mL。浓度为100mg.g-1的Cu2 经在最佳制备条件下得到的烟梗纤维素黄原酸酯处理后,Cu2 的去除率可高达99.84%。吸附动力学研究表明,烟梗纤维素黄原酸酯对Cu2 吸附量为10.24 mg.g-1。废烟梗制备纤维素黄原酸酯,用于去除Cu2 具有价格低廉、制备简单、去除率高等优点。     

纤维素基磁性聚偕胺肟树脂的研究──Ⅰ.树脂吸附二价重金属离子

碱式纤维素基磁性聚偕胺肟树脂（BMAO）吸附Co2+、Ni2+、Zn2+、Cd2+、和Cu2+、Hg2+、Pb2+二价重金属离子的起始速度和平衡吸附容量有很大的差别,认为是与离子结构及配位活性有关。吸附速度同受粒内扩散过程所控制。Cu2+、Hg2+和Pg2+在BMAO上吸附符合Freundlich等式和Langmuir等温吸附方程。吸附结果可能是生成1：1配合物。     

细菌纤维素苯甲酸酯的合成与表征

以细菌纤维素（BC）为原料,通过酯化反应制备细菌纤维素苯甲酸酯（BBC）,探讨了硝基苯用量、反应时间、反应温度以及苯甲酰氯用量对细菌纤维素苯甲酸酯取代度的影响。分别用红外光谱（FTIR）、差示扫描量热法（DSC）、偏光显微镜（POM）和广角X-射线衍射（WAXD）对产物结构、热致液晶织构和性能进行了表征。结果表明,细菌纤维素苯甲酸酯在281．7～356．3℃之间可以形成近晶型液晶相,其熔点和清亮点比已报道的植物纤维素苯甲酸酯的更高。     

纤维素基磁性聚偕胺肟树脂的研究 Ⅴ.铜副族离子在树脂上的吸附与氧化还原反应

研究了Cu2 +、Ag+和AuCl-4 在碱式纤维素基磁性聚偕胺肟树脂(BMAO)上的吸附行为。实验结果表明 ,吸附速度受粒内扩散所控制。测得吸附起始速度的顺序是Ag+>AuCl-4 >Cu2 +,认为与水合离子尺寸有关。根据扫描电镜观察和吸附动力学研究结果 ,提出并讨论了吸附 /交换和氧化还原反应机理     

细菌纤维素制备及吸附金属离子的研究进展

细菌纤维素（BC）是一种由微生物发酵制备的纤维素,具有独特的结构和物理化学性质。BC分子存在大量的羟基,具有超细网状纳米纤维结构,比表面积高,对溶液中金属离子有良好的吸附性能。本文对细菌纤维素制备条件（菌种、常用碳源及助剂）、细菌纤维素吸附重金属离子及机理的研究进展进行了总结及展望。     

多糖改性细菌纤维素的制备

合成细菌纤维素时向培养基中添加了海藻酸钠、羧甲基纤维素、羧甲基壳聚糖等多糖,制备出了性能更优异的改性细菌纤维素。采用红外光谱和扫描电镜对所得产物进行表征,并测试了合成纤维素的产量、湿膜含水量以及对金属离子的吸附性能。     

Cationization of cellulose fabrics by polyallylamine binding

Novel anion exchange materials was prepared from cellulose fabrics (cotton‐ and rayon‐cloths) by binding polyallylamine to aldehyde groups introduced by partial oxidation of cellulose via sodium periodate treatment. Degree of oxidation (D.O.) was controlled to 2–8% by the amount of oxidant. Polyallylamine (MW: 60,000, 5000, and 1000) was bound to cellulose by reductive amidation via Schiff base formation. Amount of bound amino groups was determined by conductometric titration. With the same cellulose material and degree of oxidation, the level of cationization was strongly dependent on molecular weight of polyallylamine, its concentration, and the pH of reaction mixture. Influence of these factors could be interpreted based on the porous structure of cellulose and behavior of polyallylamine in the solution. In summary, the level of cationization could be maximized by using high concentration of low‐molecular weight polyallylamine under pH as high as possible. The maximum exchange capacity, ～2.5 meq/g, was obtained by a combination of rayon cloth, oxidation degree of 8%, polyallylamine (MW: 1000) concentration of 10% (w/w) in the reaction mixture, and at pH 11.6. The cationized cellulose showed an adsorption capacity of 1.5 g hemoglobin/g cellulose. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1668–1672, 2006     

Preparation of amidoximated bacterial cellulose and its adsorption mechanism for Cu2+ and Pb2+

Amidoximated bacterial cellulose (Am‐BC) was prepared through successive polymer analogous reactions of bacterial cellulose with acrylonitrile in an alkaline medium followed by reaction with aqueous hydroxylamine. It was used as an adsorbent to remove Cu²⁺ and Pb²⁺ from aqueous solutions. The adsorption behaviors of Cu²⁺ and Pb²⁺ onto Am‐BC were observed to be pH‐dependent. The maximum adsorption capacity of 84 and 67 mg g^–1 was observed, respectively, for Cu²⁺ and Pb²⁺ at pH 5. Scanning electronic microscopy (SEM) indicated that the microporous network structure of Am‐BC was maintained even after the modifacation. The adsorption mechanisms for Cu²⁺ and Pb²⁺ onto Am‐BC were investigated by fourier transform infrared spectroscopy (FTIR), ζ potential measurement and X‐ray photoelectron spectroscopy (XPS). The results revealed that the mechanism for the adsorption of Cu²⁺ onto Am‐BC could be mainly described as between metal ions and nitrogen atom in the amidoxime groups or oxygen atom in the hydroxyl groups. However, in the adsorption process for Pb²⁺, precipitation played the important role along with electrostatic interactions, although chelation action also existed in the process accounted for the adsorption process. The regeneration of Am‐BC was studied by treatment with a strong complexing agent, ethylenediaminetetracetic acid (EDTA). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

硫脲型螯合纤维素对铜吸附性能的研究

将自制合成的三种新型硫脲型螫合纤维素——硫晚棉纤维（CC－TU），氨基硫脲棉纤维（CC－TSC）和二苯硫脲棉纤维（CC－DPTU）应用于钢的吸附性能的研究，采用火焰原子吸收法测定选择了吸附和解吸的最佳条件。在所选择条件下，这些螫合纤维素对钢具有吸附速度快、吸附完全，吸附能力强，解吸容易和洗脱体积小等特点。     

细菌纤维素再生前后结构与性质上的差异

对比研究了细菌纤维素和再生细菌纤维素的结构与性质上的差异,揭示了细菌纤维素在氯化锂（LiCl）／二甲基乙酰胺（DMAc）溶剂体系下溶解,经水浴凝固再生前后的形貌、大分子结构、晶型及尺寸、物理机械性能、含水保湿性上的变化,为再生细菌纤维素的应用提供理论依据。     

Adsorption removal of Cu2+ and Ni2+ from waste water using nano‐cellulose hybrids containing reactive polyhedral oligomeric silsesquioxanes

Cellulose is an important biomass in natural material fields. Reactive polyhedral oligomeric silsesquioxane (R‐POSS) bearing multi‐N‐methylol groups is novel high reactive POSS monomer. The nano‐cellulose hybrids containing R‐POSS were synthesized by crosslinking reaction. It was interesting to investigate properties and applications of hybrids containing R‐POSS. In this work, nano‐cellulose hybrids as novel biosorbent were used for adsorpting copper and nickel ions in aqueous solution. Adsorption kinetics and equilibrium isotherm of Cu²⁺ and Ni²⁺ on the nano‐cellulose hybrids were investigated. The results showed that R‐POSS had been grafted to cellulose macromolecule. The nano‐cellulose hybrids could form new adsorptive position for heavy metal ions. The adsorption capacities of hybrid materials were obviously higher than that of control cellulose. The adsorption of heavy metal ions on nano‐cellulose hybrids followed the second‐order model. The equilibrium isotherms for adsorpting copper and nickel ions on the hybrids followed Langmuir isotherm model. Nano‐cellulose materials containing POSS as biosorbents or ultrafiltration membranes would be used in separation of toxic heavy metal ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

盐交换凹凸棒黏土的理化性质及其对双氯芬酸钠吸附性能的影响

将凹凸棒黏土采用不同价态的硫酸盐和相同价态不同用量硫酸盐交换后,通过红外光谱、扫描电镜、比表面积和ζ电位的测定,考察了盐交换处理对凹凸棒黏土微结构和理化性能的影响。在此基础上,考察了处理凹凸棒黏土对双氯芬酸钠的吸附影响。结果表明,金属盐交换凹凸棒黏土对双氯芬酸钠的吸附量不仅与所交换金属离子的价态有关,更与凹凸棒黏土的微孔比表面积和微孔体积有关。当硫酸铝用量为凹凸棒黏土量的0.5%时,其交换凹凸棒黏土对双氯芬酸钠的吸附量最大,达到了126 mg/g,与凹凸棒黏土原矿相比,吸附量提高了近4倍。     

阳离子木屑纤维素的制备及其对水中2,4-二氯苯酚的吸附性能

以3-氯-2-羟丙基三甲基氯化铵(CTA)为醚化剂,对木屑纤维素(MC)进行了改性,并对产物进行了表征. 探讨了阳离子木屑纤维素用量、pH值、吸附温度、吸附时间等因素对水溶液中2,4-二氯苯酚(2,4-DCP)静态吸附效果的影响. 结果表明,阳离子木屑纤维素的制备条件为：CTA/MC质量比2.0,反应时间2.0 h,反应温度30℃,NaOH溶液浓度30%(w). 阳离子木屑纤维素对水溶液中2,4-DCP的最佳吸附条件为：pH 8.0,吸附时间90 min,吸附温度25℃. 此条件下,处理100 mL 2,4-DCP溶液(50 mg/L)的吸附率可达88.92%,吸附容量为1.482 mg/g. 木屑纤维素经改性后,对水中2,4-二氯苯酚存在化学吸附.