【作者】 陈鲁生；

【导师】 陈德展； 郝京诚；

【作者基本信息】 山东师范大学 ， 物理化学， 2004， 硕士

【摘要】 论文工作包括壳聚糖及其衍生物制备条件的研究和它们在造纸中段废水处理中的应用研究两方面内容。 壳聚糖（Chitosan）是氨基葡萄糖的直链多聚糖，分子式为(C₆H₁₁NO₄)n，与纤维素的化学结构很相似，可由甲壳质（Chitin）脱去乙酰基而制得。壳聚糖是一种半透明的片状固体，由于分子中带有—NH₂基团而呈碱性，可溶于许多稀酸中（如甲酸、乙酸、盐酸）。壳聚糖分子间存在强氢键，一般不溶于有机溶剂，在强酸中溶解，分子可发生降解。因为壳聚糖是直链型高分子多糖化合物，含有氨基和羟基，可发生水解、羟甲基化、磺化、氧化、络合、缩合等反应。由于壳聚糖分子中有游离氨基存在，具有阳离子型聚电解质性质，可直接作絮凝剂，也可经改性后作絮凝剂使用。 由于壳聚糖主要在酸性条件下使用，其应用范围受到很大限制。为扩大其应用范围，我们经过化学改性，以甲壳质和壳聚糖为母体，制备出了完全水溶性壳聚糖、O—羧甲基壳聚糖、O—羧甲基甲壳质等水溶性的阴、阳离子型絮凝剂，并找出了最佳制备条件。制备出的壳聚糖系列衍生物即可单独作絮凝剂使用，也可作为助剂与其它絮凝剂复合使用。它对无机悬浮固体和多种有机物均有良好的絮凝作用。本课题成功地首次将其应用于造纸中段废水的处理中，取得了良好的预期效果。 为便于与无机絮凝剂和无机高分子絮凝剂的絮凝效果进行比较，我们还合成出了具有不同Al³⁺／SO₄^2-摩尔比的聚合硫酸铝（PACS），并对其在废水中的絮凝效果进行了研究。 我们分别以壳聚糖及其衍生物、铝盐、铁盐、氧化钙、聚合硫酸铝和阴、阳离子型聚丙烯酰胺为絮凝剂，将它们各自对造纸中段废水的处理效果进行了研究，并找出了废水处理的适宜pH值及絮凝剂的用量。并对絮凝效果及机理进行了探讨。 研究表明，对造纸中段废水的处理效果，壳聚糖及其衍生物的絮凝效果优于无机絮凝剂，同时也优于阴、阳离子型聚丙烯酰胺。它们对废水CODcr的去除率为78～85％，悬浮物的去除率为63～74％，色度的去除率为50～80％。山东师范大学硕士论文 为提高废水的处理效果，降低处理成本，我们将壳聚糖及其衍生物与硫酸铝和氧化钙组成复合絮凝剂对废水进行了处理。实验表明，它们对造纸中段废水的处理效果优于单独使用时的效果。其中以A13+中和废水中的负电荷，以壳聚糖及其衍生物进行吸附、架桥作用而使溶液中的粒子混凝沉淀。当壳聚糖及其衍生物的浓度为10^soppm、硫酸铝的浓度为300^sooppm、氧化钙的浓度为300 ppm时，可使废水CODcr的去除率达90一99%、悬浮物的去除率达78一88%、色度的去除率达79一95%。处理后的废水，CODer降至7一72m岁L、悬浮物浓度降至25一40m岁L、色度降至4一16倍，废水的颜色基本全部去除，为澄清透明液体，水质达到了国家规定的污水排放一级标准。 利用该工艺处理造纸中段废水，具有絮凝效率高、絮凝剂用量少、矾花大易处理、CODcr、悬浮物及色度去除率高、无毒无味、可生物降解和处理后的废水不产生第二次污染等许多显著特点。 本论文的创新性工作: 1.较系统地研究了甲壳质、壳聚糖、水溶性壳聚糖、O一梭甲基甲壳质、O一梭甲基壳聚糖的制备条件，对影响产品产率和质量的各种反应条件进行了优化，该工作对工业生产具有一定的指导作用。 2.首次将“环境友好”的壳聚糖及其衍生物作为絮凝剂应用于造纸中段废水的处理中，并取得了良好的处理效果。壳聚糖及其衍生物与硫酸铝和氧化钙组成的复合絮凝剂，对废水CODer的去除率达90⁹9%、悬浮物的去除率达78⁸8%，色度的去除率达79一95%。该絮凝剂可生物降解，处理后的废水不产生第二次污染。 3.较系统地将壳聚糖及其衍生物与铝盐、铁盐、氧化钙、聚合硫酸铝和阴、阳离子型聚丙烯酞胺对造纸中段废水的絮凝效果进行了对比研究。关键词:分类号:絮凝剂;壳聚糖及其衍生物;制备条件;应用;造纸中段废水;处理。0 648令更多还原

【Abstract】 Chitosan is a straight chain multi-polysaccharide of amino-glucose with a formula of C6H11NO4)n and similar to cellulose in chemical structure. It is the deacetylated product of chitin. Chitosan is a half-transparent sheet solid and behaves alkaline properties due to the amino-group(-NH2) in its molecule. It can be dissolved in dilute acid such as formic acid, acetic acid and hydrochloric acid etc hut the degree of polymerization will reduced when it is dissolved in strong acid. Generally chitosan cannot be dissolved in organic solvent because of the strong inter-molecular hydrogen bonds. Chitosan is a straight-chain polymer with amino-group(-NH2) and hydroxyl(-OH) so it can induce some reaction such as hydrolysis, hydroxymethylation, sulfonation, oxidation, complexation, condensation etc. Because of the amino-group in its molecular structure, chitosan can be used directly as a flocculant or improving its flocculation by modifying its structure. The main results of this study are as following:Considering the chitosan used mainly in acid medium, its utilization is limited. In order to expand its utilization study, chemical modification has been conducted. The chitosan and chitin were used as parent materials to prepare water-soluble chitosan, O- carboxymethylchitosan, and O- carboxymethylchitin etc. which were used flocculants with anion or cation. The optimal reaction conditions have been obtained to prepare them. The products of a series derivatives prepared in this study can be directly used as flocculants or as a coagulant aid to other flocculants, which show a good flocculating effects to treatment with inorganic solid suspensions or many kinds of organic compounds. In this paper, the flocculating characteristics of modifying chitosan and chitin have been systematically investigated in treatment with the waste water from the middle process in making paper and expected results have beenobtained.In order to compared the flocculating effects between the inorganic flocculants and chitosan and its derivatives, poly-aluminium sulfate(PACS) with different ratio of mole Al3+/ SO42- were synthesized under preferential preparing conditions. A series of compounds including derivatives of chitosan, aluminium salt, iron salt, calcium oxide, poly-aluminium sulfate, and polyacrylamide with anion or cation have been used respectively as a flocculant in treatment with the waste water from the middle process in making paper. The optimal pH value and amount of the flocculants addition of treating with the waste water have been determined experimentally and a tentative flocculating mechanism for the samples above mentioned has been discussed.The results show that chitosan and its derivatives have better flocculating effects than inorganic flocculants and polyacrylamide with anion or cation. The ratio of elimination of chemical oxygen demand measured by potassium dichromate (CODcr), suspension, and colority reaches up to 78 ~ 85 %, 63 ~ 74 %, and 50-80%, respectively.A complex flocculant including chitosan and its derivatives, aluminium sulfate and calcium oxide has been investigated in order to improving the treatment effects and reducing the treatment cost of the waste water. The complex flocculant shows better flocculating effects than single one of them. The ion Al3+ neutralizes the negative charges of the waste water and the chitosan or its derivatives adsorbs and binds the particles of the solution and flocculation occurs. The ratio of elimination of CODcr, suspension, and colority reaches up to 90 ~ 99 %, 78 ~ 88 %, and 79-95%, respectively when the concentration of the chitosan or its derivatives, aluminium sulfate, and calcium oxide is 10-50 ppm, 300~500ppm and 300 ppm, respectively. The concentration of CODcr, suspension and colority reduces up to 7-72 mg/L, 25~40mg/L, and 4-16 times, respectively in the treated waste water which is transparent liquid and no color is found. The quantity of the treated waste water accords with the first-order national standard of waste water exhaust.The procedure of treatment with the waste更多还原