六价铬在具有渗透性反应墙的渗流槽中迁移实验研究

地下水中六价铬的污染修复是目前地下水污染修复研究的热点课题之一。以室内模拟为基础,进行了六价铬[Cr（Ⅵ）]随水流迁移的渗流槽实验,以及利用课题组研发的新型壳聚糖材料填充渗透性反应墙（PRB）,进行六价铬吸附试验研究。结果表明：在重金属迁移实验中,地下水的流速是影响Cr（Ⅵ）在含水层中迁移的主要因素,含水层介质的变化都会对Cr（Ⅵ）的迁移发生重要的影响。实验过程中,从进水口到出水口各个取样点依次出现Cr（Ⅵ）的质量浓度峰值,并且随着时间的延长,质量浓度峰值没有减少的趋势,证明了Cr（Ⅵ）在含水介质中基本上没有吸附。Cr（Ⅵ）的质量浓度峰值在含水介质中的持续时间不长,由于弥散作用造成了在相当长的时间内的较明显的拖尾现象。模拟渗透性反应墙的实验中,在同样的流速条件下,Cr（Ⅵ）的质量浓度峰值的出现时间相对先前的实验有明显滞后,并且质量浓度也有明显的减少,说明新型壳聚糖材料对Cr（Ⅵ）有较高的吸附作用,再达到质量浓度的峰值后,墙体后面的采样口中Cr（Ⅵ）的质量浓度减少的更为平缓,说明随着水流的流动,吸附在壳聚糖材料上的Cr（Ⅵ）有缓慢的析出。     

聚合氯化铝-壳聚糖复合絮凝剂的合成及在蓝藻沼液预处理中的应用

以聚合氯化铝(PACl)和壳聚糖(CTS)为主要原料合成了聚合氯化铝-壳聚糖(PACl-CTS)复合絮凝剂,考察了PACl与CTS的质量比、反应温度、反应液pH和反应时间等因素对PACl-CTS絮凝性能的影响,优化出PACl-CTS合成最佳工艺条件为:温度控制在70℃,m(PACl)∶m(CTS)=4∶1,反应时间1 h,pH值为4.通过红外图谱(IR)和扫描电镜(SEM)对PACl-CTS的微观结构进行了表征,表明PACl以一定的晶体结构镶嵌在CTS中,PACl和CTS之间存在一定的相互作用,而不是简单的复配.将合成的PACl-CTS应用于蓝藻沼液废水处理,结果表明,PACl-CTS对浊度、COD、TP具有良好的絮凝性能,当投加量为21.0 mg.L-1时,浊度、COD、TP的去除率分别达到了98.15%、67.78%和84.05%,可作为新型高效絮凝剂应用于蓝藻沼液废水预处理.     

Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Polyethylenimine （PEI）-modified chitosan was prepared and used to remove clofibric acid （CA） from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy （SEM） showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg· g^-1 for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg· g^-1 on the porous chitosan. The CA adsorption on the PEI- modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceu- ticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI- modified chitosan has a potential application for the removal of some anionic rnicropollutants from water or wastewater.     

膨润土负载壳聚糖对Cu2+的吸附作用

将壳聚糖与膨润土结合,研制出一种复合吸附剂,并用于溶液中Cu2 的脱除,取得很好的效果,脱除率达到70%以上.通过X-射线衍射实验研究了改性膨润土的结构和改性机理.结果表明,膨润土的片状层结构未发生变化,壳聚糖仅吸附在膨润土的内外表面.该吸附剂具有投药量少、稳定性高、操作简单、无再次污染等优点.     

甲壳素及壳聚糖的制备与利用

本文综述了从水产加工废弃物虾、蟹壳中制取甲壳素和壳聚糖的方法。简要介绍了甲壳素和壳聚糖及其衍生物的开发应用现状,供有关方面充分利用甲壳素资源参考。     

Biodegradation by Composting of Surface Modified Starch and PVA Blended Films

Several starch/PVA/glycerol polymer blends were prepared by a solution casting technique and examined for biodegradation by composting over 45 days. Within this time frame, the starch and glycerol components were fully degraded, leaving the PVA component essentially intact. The lowest PVA content film (20%) was selected as a polymer with enough PVA to impart important physical characteristics, but also enough starch to be considered biodegradable. The film characteristics were further improved by surface modification with chitosan. This modification did not interfere with the biodegradation of the starch component. Furthermore, there was slight evidence that PVA biodegradation had been initiated in composted, surface modified starch/PVA blends.     

甲壳素和壳聚糖在水处理中的应用

介绍了天然有机高分子化合物——甲壳素和壳聚糖的制备、化学结构和特性，阐述了其在水处理中的应用及发展前景。甲壳素和壳聚糖的来源广泛，其性能优良、无毒、无公害、可生物降解，可用作吸附剂、絮凝剂、分离膜材料、离子交换剂和杀菌剂，是一类非常有开发利用前景的新型水处理材料。     

Oxygen and Water Barrier Properties of Coated Whey Protein and Chitosan Films

Films of whey protein and chitosan acetic acid salt have lower oxygen permeability than, for example, ethylene-co-vinylalcohol under dry conditions, but water and water vapor seriously impair the gas barrier properties. To reduce the oxygen permeability at 90% relative humidity and the water-vapor transmission rate at 100% relative humidity, the films were coated with an alkyd, a beeswax compound, or a nitrocellulose lacquer. Permeability and transmission rate measurements were performed in accordance with standard methods and showed that the beeswax compound and the nitrocellulose were appropriate as water-vapor barriers. Overall migration to water was measured after 10 days exposure time, with the coated surface exposed to the water, showing that the alkyd-coated and the nitrocellulose-coated films were both below the safety limit for food contact. Water absorbency tests, performed by the Cobb method, showed that the films coated with the beeswax compound or with nitrocellulose lacquer exhibit lower absorbency than the alkyd-coated films.     

壳聚糖絮凝剂处理废水的研究进展

壳聚糖是一种新型天然高分子絮凝剂，对动植物无毒、无害。壳聚糖可以用于处理印染、味精、食品、含重金属离子废水等。系统地阐述了壳聚糖絮凝剂的结构及在水处理方面的研究应用情况，讨论了其絮凝机理，提出了看法。     

壳聚糖对酸性染料的吸附性能

在不同的壳聚糖浓度、pH和温度条件下，采用分光光度法测得吸附后的染料浓度，得到了壳聚糖对酸性染料的最佳吸附条件，即在固定染料浓度和体积的情况下，壳聚糖的投入量在500mg、pH值为6、温度为室温、吸附时间为2h左右条件下吸附最佳，其结果将为利用壳聚糖处理印染废水提供一定的理论根据。