【作者】 曾德芳；

【导师】 袁继祖；

【作者基本信息】 武汉理工大学 ， 矿物加工工程， 2006， 博士

【摘要】 絮凝是水处理中净化水质的常用手段和方法，但目前常用的传统絮凝剂聚合三氯化铝（PAC）和聚丙烯酰胺（PAM）等在水处理中均易产生二次污染，PAC水解后产生的铝离子通过饮用水进入人体会导致贫血、脱发和大脑痴呆等多种疾病，PAM水解后产生的丙烯酸和有机胺等有机污染物同样危害人体健康。因此，如何研制一种二次污染小、絮凝效果好的新型环保型水处理絮凝剂是当前水处理领域急待解决的重要课题。为此，本课题以湖北价廉丰富的累托石和红龙虾壳为主要原料，制备出一种新型高效环保型水处理絮凝剂，并将其用于典型的给排水处理，取得了较传统絮凝剂更加环保、价廉、高效的应用效果，其主要研究内容和结果包括：1，采用新的制备工艺，将天然累托石制备成铝交联型改性累托石絮凝剂，使其对污水中的COD和SS的去除率较天然累托石分别提高了25.3％和35.0％，药剂成本下降了5％。2，采用新的制备及清洁生产工艺，将红龙虾壳制备成壳聚糖絮凝剂，使其与传统工艺相比，制备成本下降了19％、总反应时间缩短了一半，产率提高了5％，污染负荷降低了54.3％，吨产品废物利用值提高了4倍，且主要性能指标均达到美国Sigma公司同类产品的技术要求。3，首次提出将改性累托石与壳聚糖复合用于给排水的絮凝处理，并确定了该复合絮凝剂的原则性配方与最佳处理工艺，其中给水处理的原则性配方为自来水体积（浊度95±10NTU）：1％改性累托石体积：0.1％壳聚糖体积=1000：1：0.02；污水处理的原则性配方为污水体积(COD=500±100mg·L^-1)：1％改性累托石体积：0.5％壳聚糖体积=1000：8：0.2。4，将该絮凝剂用于自来水、石化废水、造纸废水、啤酒废水、油漆废水、污泥脱水等典型给排水的絮凝处理，无论在在性价比方面还是在环境友好方面均优于传统絮凝剂，尤其将其用于自来水处理，可使水中铝离子含量较传统絮凝剂下降56.25％，使饮用水更加安全坏保。5，根据絮凝剂基本理论和改性累托石、壳聚糖的结构特征，对该复合絮凝剂的絮凝机理及其特点进行了理论分析与研究。研究结果表明，改性累托石的絮凝吸附性能优于天然累托石的原因在于，改性累托石中铝交联剂的“插层作用”导致累托石的层间距扩大，使其层间域（Is）进一步开放、撑大，从而导致其吸附量和吸附范围扩大、吸附性能更好。壳聚糖因其分子链上含有多个羟基（-OH）和氨基（-NH₂）、以及它在水中易与H⁺离子质子化成阳离子型聚电解质，决定了它在水处理中主要存在三种絮凝机理：螯合作用、电中和作用和吸附架桥作用，其中螯合作用主要去除水中金属离子、电中和作用主要去除水中有机污染物COD和固体悬浮物SS、吸附架桥作用主要是提高复合絮凝剂的整体絮凝性能。选择一定的无机絮凝剂与有机絮凝剂复合使用，可达到协同增效、优势互补、整体絮凝性能大大提高之目的。更多还原

【Abstract】 Flocculation is a kind of method and technique of purifying water in common use.But the conventional flocculants such as polyaluminium chloride （PAC） andpolyacrylamide （PAM） in water treatment are prone to produce secondary pollution,the aluminum ions that is produced from hydrolysis of PAC in water come intohuman body via feed water and cause various diseases such as anaemia, hair-losingand brain dementia etc., crylic acid and amine that are produced from hydrolysis ofPAM would harm human health too. So how to prepare a kind of novelenvironmentally friendly flocculant which is of less pollution and better flocculatingperformance is a very inportant subject and an urgent task in water treatment fieldrecently. Therefor, a kind of novel high-effect environmentally friendly flocculanthad been prepared by using the natural resources in Hubei province such as rectoriteand the red lobster shell which are at low prices and abundant amount. Comparedwith the conventional flocculant, this novel composite flocculant has a moreenvironmentally friendly function, lower price and higher effect by using it to treattypical feed water and wastewater. The main research contents and results of thispaper are included as following:1, By adopting the novel process, the modified rectorite flocculant was prepared fromthe natural rectorite. Compared with the natural rectorite, its removal rate of COD andSS were increased by 25.3％and 35.0％respectively, and its medicament cost wasdecreased by 5％.2, By adopting the novel preparing and clean production process, the chitosanflocculant was prepared. Compared with the conventional process, the cost ofpreparing chitosan was decreased by 19％, the time of preparing chitosan wasshortened by 50％, the total yield of perparing chitosan was increased by 5％, thecontaminating burthen in preparing chitosan was reduced by 54.3％, the value ofrecycling byproduct in preparing a ton of chitosan product was enhanced by 4 times,moreover, the main performance parameters of this chitosan had reached to the ones of the same product made in Sigma Co. of the U.S.3, It’s the first time that the compound of modified rectorite and chitosan was used inthe flocculation of water treatment, and the fundamental proportion and optimaltreating process of this composite flocculant were put forward. The fundamentalproportion of treating feed water was the vol.of feed water （cloudy degree=95±10NTU）: the vol. of 1% modified rectorite liquor: the vol. of 0.1% chitosanliquor=1000: 1: 0.02, the fundamental proportion of treating wastewater is the vol.of wastewater (COD=500±100mg·L^-1): the vol. of 1% modified rectorite liquor:the vol. of 0.5% chitosan liquor=1000: 8: 0.2.4, Compared with conventional flocculants, this composite flocculant is of moreenvironmentally friendly function, lower price and better effect in treating water suchas feed water, petrochemical wastewater, paper-making wastewater, bear wastewater,paint wastewater and sludge dehydrating etc., especially, in treating feed water usingthis flocculant, the concentration of aluminum ions in the water was decreased by56.25%, so that feed water treated by this flocculant is more secure and moreenvironmentally friendly.5, According to the flocculation theory and the structure characteristic of the modifiedrectorite and chitosan, this paper analyzed and researched the flocculating mechanismand properties of this flocculant theoretically. The research results show that thereason why the flocculating performance of the modified rectorite is better thannatural rectorite is that the "inserted function" of linked aluminium reagent inmodified rectorite, this inserted function enable rectorite to produce a larger wideningof the space and a wider opening of the field between the layers of Is, so that themodified rectorite is of a wider adsorptive range and a more bulky adsorptivecapability. On the other hand, there are lots of amino group （-NH₂） and hydroxyl（-OH） on the molecule chain of chitosan, chitosan can be protonated with H⁺ intocationic polyelectrolyte in water. This characteristic of chitosan enable chitosan to beof three kinds of flocculating mechanism in water treatment: chelation, electricneutralization and bridge linking function, in which the main function of chelation isto remove the metal ions, the main function of electric neutralization is to remove theCOD and SS in the treated water, and the main function of bridge linking is to improve the whole flocculating performance of the composite flocculant. So thecombining flocculating by using certain inorganic flocculant and organic flocculantcan come to the goal of cooperating enhancing the flocculating effect, complementingthe other’s deficiency mutually, and improving the whole flocculating performanceconsumedly.更多还原