羧甲基壳聚糖对染料废水的脱色研究

纺织工业是我国重要的经济部门,也是我国工业废水的排放大户,其中印染废水排放量又占纺织工业废水排放量的80%,已成为我国各大水域的重要污染源。印染废水的两大污染指标是色度和COD,污染的特点和处理的难点是色度高,脱色困难[1-2]。作为一种天然生物高分子,壳聚糖(chitosan,简称CTS)以其独有的絮凝、成膜、吸附、螯合等性能在印染废水脱色研究领域得到广泛应用[3-8]。作为絮凝剂处理废水时,壳聚糖由于水溶性差而需先溶于稀酸,应用受到一定限制,故人们纷纷将其改性制成水溶性的羧甲基壳聚糖(carboxy-methyt chitosan,简称NOCC)。张秋华[…     

壳聚糖改性凹凸棒土絮凝采收小球藻的研究

以壳聚糖改性凹凸棒土作为普通小球藻Chlorella vulgaris的絮凝剂,CaCl2为助凝剂,研究了絮凝采收小球藻的工艺条件。结果表明,最佳絮凝条件为:絮凝剂0.4g/L、壳聚糖/凹凸棒土为1∶12、助凝剂CaCl2为0.2g/L、溶液的pH为9.0,此条件下小球藻絮凝率达到95%以上。絮凝剂的扫描电镜图和BET比表面积(BET)数据显示,改性后的凹凸棒土以一定的空间结构状吸附连接壳聚糖,有效增加了絮凝剂的比表面积,有利于小球藻的吸附。研究采用的原料价格低廉、安全环保,絮凝剂的制备简单且絮凝效率高,可广泛用于工业化生产中微藻的采收。     

复合型高效絮凝脱色剂处理印染废水的研究

选用自制的双氰胺甲醛作为絮凝脱色剂处理高浓度印染废水,并与硫酸铝、三氯化铝作了对比实验。考察了投加量、pH值、反应温度等因素对絮凝效果的影响。实验结果表明在用量较少并且其它操作条件相同的情况下,双氰胺甲醛制备的脱色絮凝剂具有很好的絮凝脱色效果及COD_(Cr)去除率。在最佳的操作条件下(投加量120 mg/L,pH=7,反应温度25℃),此脱色絮凝剂对分散、酸性、活性印染废水的COD_(Cr)去除率分别为79.1%、78.5%、79.0%,对分散、酸性、活性印染废水的脱色率分别为94.0%、97.1%、72.9%,减轻了后续处理难度。在与无机絮凝剂的对比试验中,在相同的条件下有机絮凝剂的处理效果总体比无机絮凝剂的处理效果好。     

聚合硅酸氯化铝的研制

应用硅酸钠、氯化铝在一定条件下制成聚硅酸氯化铝 ( PASC)絮凝剂 ,并对其稳定性 ,Si O2 百分含量 ,Al/Si摩尔比等进行了研究 ,得出影响 PASC稳定性的主要因素有二 :一是溶液中的 Si O2 浓度 ,当 Si O2 的浓度在1 %左右时 ,溶液的凝胶时间在 3 0 d以上 ,而当 Si O2 浓度在 3 .0 %时 ,其絮凝时间仅为 1 0 d;二是 Al/Si摩尔比 ,最佳摩尔比约为 1 .5。对制得的 PASC进行了处理污水 (浑浊水、剩余氨水 )的条件实验 ,得出聚硅酸氯化铝对剩余氨水中 COD的去除率可达 94.1 % ,对氨氮的去除率达 93 .8% (二次絮凝 )。 PASC处理废水的适宜操作参数为 :投加量 1 3× 1 0 - 6 ,p H值为 6～ 7,高速搅拌 ( 1 3 0 0 r/min) 2 min,低速搅拌 ( 60 r/min) 1 0 min,静置沉淀 3 0 min～ 60 min。     

Al-Fe-Mg三阳离子聚硅酸絮凝剂的研发

为了提高腈纶废水的絮凝处理效果,研发了一种Al-Fe-Mg三阳离子聚硅酸絮凝剂。通过正交实验研究了金属溶液浓度、硅与金属比例以及铝、铁、镁之间比例对絮凝剂制备的影响。然后,将制备好的絮凝剂药液投加入废水中,研究其投加量及pH对废水处理的影响。结果表明,将聚硅酸溶液倾倒入(金属溶液浓度为0.02mol·L~(-1),Si与金属摩尔比为2∶1,金属铝铁镁摩尔比为3∶1∶2)金属溶液搅拌快速搅拌5min后静置12h,在此条件下制备的铝铁镁絮凝剂效果最佳,并且硅与金属比例是复合絮凝剂的主要影响因素,去浊率可达99.59%。     

壳聚糖改性絮凝剂絮凝性能的研究

壳聚糖是一种性能优异的天然高分子材料。由于糖环上含有氨基,在酸性溶液中易形成阳离子型聚电解质,在水处理中显示出良好的絮凝性能。为了进一步提高壳聚糖的水处理性能,人们还通过化学方法制备高效壳聚糖改性絮凝剂材料。本文以一种壳聚糖改性絮凝剂——壳聚糖接枝聚丙烯酰胺共聚物为研究对象,以高岭土悬浊液为模拟水样,通过实验室烧杯实验,系统地研究了该材料的实际絮凝性能,考察了新型絮凝剂投加量和实际絮凝效果与原水温度、浊度的对应关系,并从絮凝机理角度讨论了絮凝剂投加量的变化规律。     

双指示剂法测定壳聚糖的脱乙酰度

壳聚糖是甲壳质经浓碱脱乙酰基后得到的衍生物,具有良好的生物相容性和生物可降解性,广泛应用于医药、食品、化妆品、轻工、印染、环保和生物工程等领域[1-2]。壳聚糖脱乙酰度(简称DD%)是指壳聚糖多糖分子氨基上脱去乙酰基的百分比,其高低直接影响到壳聚糖的溶解度、絮凝能力、螯合金属离子能力和N-选择性酰化能力等物化特性,是鉴定壳聚糖产品质量的一个重要指标。目前测定壳聚糖脱乙酰度的方法有酸碱滴定     

壳聚糖对药液絮凝作用的研究

以壳聚糖为絮凝剂，研究了它对丹参水提液的絮凝情况。比较了絮凝剂加入量不同和分子量不同时，絮凝物的沉降速率，从而考察了它们对絮凝效果的影响以及所得产品的质量。     

一种复合脱色剂在印染废水中的应用研究

以甲醛、双氰胺、醋酸钠、氯化铵、氯化铝等为原料制备了一种印染废水脱色絮凝剂T-1。采用福州某纺织印染有限公司的印染废水为处理对象,以脱色率为主要考核指标,讨论了T-1的投加量、pH值、废水温度等对絮凝效果的影响。实验结果表明,双氰胺-甲醛缩聚物对印染废水具有优良的脱色絮凝效果,当投加量为100mg/L,废水温度为30℃,pH=8时,处理效果最佳,色度去除率达70%,COD去除率为78.3%。而且其絮凝性能明显优于聚合氯化铝(PAC)、聚合硫酸铝(PAS)絮凝剂。     

双水相聚合法合成阳离子聚丙烯酰胺及其絮凝性能

以聚乙二醇（PEG）水溶液为分散剂,过硫酸铵（KPS）为引发剂,采用双水相聚合法,用新型阳离子单体丙烯酰氧乙基三甲基氯化铵（DAC）与丙烯酰胺（AM）共聚,制备了一系列新型阳离子聚丙烯酰胺(CPAM)类絮凝剂,讨论了单体含量对聚合物相对分子质量、转化率和阳离子度的影响。 并对黄河水做了絮凝实验,讨论了CPAM投加量、pH值、搅拌速率、搅拌时间及静置时间对絮凝效果的影响。 所得CPAM的阳离子度随DAC含量增加而增大,CPAM的平均相对分子质量和转化率随DAC含量增加略有下降。 当CPAM投加量为0.3 mg/L,pH=6,以100 r/min搅拌15 min后,再静置10 min,絮凝效果最好,去除率达到92%。     

Gelation time and degradation rate of chitosan-based injectable hydrogel

Gelation time and degradation rate of thermally-sensitive aqueous solutions of chitosan/Gp (glycerophosphate disodium salt) have been studied. The effects of different parameters such as Gp salt concentration, solution temperature, degree of deacetylation of chitosan (DDA) and drug loading on the gelation time have been investigated. Gravimetric analysis, gel permeation chromatography and FTIR spectrophotometry were used to investigate the influence of the DDA and concentration of chitosan solution on hydrogel degradation. The presented results indicated that gelation time decreases by increasing Gp salt concentration, temperature, concentration and DDA of chitosan solutions, while drug loading has no significant effect on gelation time. Slower degradation profile was recorded for hydrogel with the higher DDA and concentration of chitosan in the primary solution. FTIR studies indicated that the chemical structure of chitosan macromolecules does not change significantly during the degradation. It could be concluded that biodegradation of chitosan hydrogel occurred via its surfaces.     

蘑菇中甲壳素的提取及结构研究

以蘑菇为原料提取甲壳素,并制备壳聚糖。通过滴定法测定由蘑菇制备的壳聚糖的脱乙酰度,用乌氏黏度计测定了比浓黏度,并研究了制备工艺中加热温度和碱处理时间对它们的影响,计算了其产率;对以蘑菇为原料制取的甲壳素、壳聚糖的结构通过红外光谱进行表征。结果表明,在碱处理时间为24h、加热温度为100℃的条件下有较高的脱乙酰度;比浓黏度随着碱处理时间的延长、加热温度的增加都呈下降的趋势;壳聚糖产率为1．69％。制取的甲壳素、壳聚糖的红外光谱图表明,甲壳素在蘑菇中主要是以α-构型存在,α-构型甲壳素在浓碱中经过脱乙酰后生成β-构型的壳聚糖。     

甲壳胺的结晶度和结晶形态

首次制得非晶甲壳胺样品,并给出了根据X射线衍射图精确计算甲壳胺结晶度的公式,计算得知甲壳胺的结晶度随脱酰度的增加(74%～85%)而增加,发现甲壳胺的结晶结构和结晶形态与制样条件有关。     

O-羧甲基壳聚糖纳米微粒制备及对Ni~(2+)吸附研究

将壳聚糖与氯乙酸反应,通过控制反应条件制备了取代度为0.71的O-羧甲基壳聚糖,将改性后的O-羧甲基壳聚糖与多聚磷酸钠反应,制备了粒径分布在370-710nm的O-羧甲基壳聚糖纳米微粒,透射电镜观察表明该微粒呈球状,平均粒径为450nm.在此基础上研究了O-羧甲基壳聚糖纳米微粒对工业电镀镍废水Ni~(2+)吸附性能,考察了溶液pH、Ni~(2+)起始浓度、平衡吸附时间、粒径等因素的影响,结果表明:O-羧甲基壳聚糖微粒最佳吸附条件是Ni~(2+)溶液pH为8.0、Ni~(2+)溶液起始浓度为33.28mg/ml、平衡吸附时间为0.5h、粒径较小的O-羧甲基壳聚糖纳米微粒对Ni~(2+)的吸附量要大于粒径较大的吸附量.     

Reaction kinetics of glycidyl trimethyl ammonium chloride and chitosan in 1-allyl-3-methylimidazolium chloride

The modification of chitosan in ionic liquids through homogeneous reactions has advantages including shorter time and simple post-treatment and the generated chitosan derivatives have high degrees of subsititution and good reproducibility. In this paper, we studied the reaction kinetics of glycidyl trimethyl ammonium chloride and chitosan in 1-allyl-3-methylimidazolium chloride. Chitosan concentration, temperature, and reaction time were studied to determine their influence on reaction kinetics. The results indicated that reaction rate increased with increases of both chitosan concentration and temperature. A first-order kinetics equation was generated, where the relationship between reaction rate constant and temperature was determined.     

Modification and Characterization of Chitosan Films Using 3-trimethoxyl Silyl Propylmethacrylate

The biodegradable flexible chitosan film was prepared by solution casting. The physico-mechanical properties, polymer loading (PL), gel content and water uptake of the chitosan film were studied. The tensile strength (TS) and % elongation at break (Eb) of the uncured chitosan film were 7.0 (MPa) and 8%, respectively. Four formulations were developed using 3-trimethoxyl silyl propylmethacrylate (TSPMA) (varied from 10–80% by weight) in methanol along with photoinitator (Darocur-1664). The raw chitosan films were then soaked in the prepared formulations and cured under UV radiation at different intensities to improve the physico-mechanical properties of the films. TS for the photocured chitosan film was 28.0 (MPa) which was 4 times higher compared to the uncured chitosan film. This TS was obtained for the formulation containing 30% silane (TSPMA) at 24th UV pass for 4 min soaking time. The maximum PL of 45.1% was obtained for the same formulation at 24th UV pass for 4 min soaking time. The water uptake and gel content of the photocured chitosan films were also studied. The scanning electron micrographs of the photocured chitosan film showed smooth surface, compact and homogeneous structure.     

海藻酸钠-壳聚糖微胶囊膜强度的研究

以乳化/内部凝胶化法制备了海藻酸钠-壳聚糖微胶囊,重点考察了成膜反应过程中影响微胶囊膜强度的几个主要参数,实验发现,壳聚糖分子量低于100000,成膜反应时间高于15min,壳聚糖溶液pH值在6.0左右时制备的微胶囊膜强度较高.初步探讨了海藻酸钠与壳聚糖两种高分子发生聚电解质络合反应的机制.     

Crystal transition from hydrated chitosan and chitosan/monocarboxylic acid complex to anhydrous chitosan investigated by X‐ray diffraction

We have studied the crystal transition behaviors from hydrated chitosan to anhydrous chitosan by X‐ray diffraction analyses. Hydrated chitosan prepared by deacetylation of crustacean α‐chitin was subjected to the two conversion methods, hydrothermal treatment and high‐humidity treatment via chitosan/monocarboxylic acid complex. The transition by hydrothermal treatment progressed with increasing treatment temperature and time, and the rapid transition occurred above 200 °C. Chitosan/acetic acid complex and chitosan/formic acid complex were prepared by immersing hydrated chitosan in acid solution. The transition from chitosan/acetic acid complex to anhydrous chitosan in high relative humidity condition proceeded with increasing temperature and was complete at 80 °C for 1 h, whereas chitosan/formic acid complex did not convert to anhydrous chitosan under the same conditions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1065–1069     

磁性壳聚糖微球的制备及对Cr(Ⅵ)的吸附性能研究

用壳聚糖包埋磁流体,用戊二醛交联制成磁性壳聚糖微球,并用红外光谱表征其结构。用制备的磁性壳聚糖微球吸附Cr(Ⅵ)离子,考察了其对Cr(Ⅵ)离子的吸附性能;探讨了吸附时间、溶液pH值、吸附剂用量、温度、Cr(Ⅵ)起始浓度以及其他离子存在对Cr(Ⅵ)离子去除率的影响。实验结果表明,磁性壳聚糖微球吸附Cr(Ⅵ)离子的最佳条件为:吸附平衡时间40 min,最佳吸附pH值6左右,磁性壳聚糖微球用量10 mg,温度升高有利于提高磁性壳聚糖微球的吸附效率,Cr(Ⅵ)离子起始质量浓度为12μg/mL,无机盐的存在引起磁性壳聚糖微球的吸附性能降低。并且考察了吸附剂的再生性能,实验结果表明磁性壳聚糖微球具有良好的重复使用性。     

歧化松香胺-壳聚糖缀合物的合成、表征及药控缓释行为

以天然可再生资源壳聚糖和歧化松香胺为原料,经由苯甲醛保护氨基的Schiff碱壳聚糖,通过环氧氯丙烷搭桥生成具有环氧活性基的壳聚糖,再与歧化松香胺发生接枝反应,首次合成了一种新型壳聚糖衍生物--歧化松香胺-壳聚糖缀合物(DRACC),通过FT-IR、UV、1H-NMR、XRD、SEM和TG-DTA等测试手段对产物进行了分析和表征.由元素分析法测得DRACC的取代度为0.506.并分别以壳聚糖和DRACC作为药物非诺洛芬钙缓释制剂的载体,研究了其在人工肠液和人工胃液中的缓释性能.结果表明,DRACC载体在人工肠液和人工胃液中均具有良好的缓释作用.