超支化纤维素基吸附絮凝双功能材料的合成及其性能研究

发布时间：2018-05-31 04:36

本文选题：纤维素 + 超支化结构　；参考：《浙江理工大学》2017年硕士论文

【摘要】：工农业废水的控制与治理是当前社会绿色可持续发展的重要课题。在传统的污水处理技术中,絮凝和吸附技术是分别针对不可溶性污染物和可溶污染物脱浊脱色最直接有效的处理方法。然而水体污染物质种类繁多,单一地使用某种絮凝剂或者吸附剂并不能把所有的污染物去除达到脱浊脱色的效果,往往需要将絮凝剂和吸附剂联合使用,才能够达到排放或使用标准。因此,研究和开发具有絮凝沉淀和吸附脱色双功能的新型材料,实现其对废水中不可溶性、可溶性污染物的同时高效去除具有重要的科学意义和应用价值。针对传统吸附或絮凝材料功能单一、去除效率不佳等问题,本论文以纤维素(CE)和支化聚乙烯亚胺(hPEI)为主要原料,通过分子设计和可控合成,制备具有超支化结构的纤维素基吸附絮凝双功能材料(hPEI-CE)。论文考察了接枝工艺技术对所制备hPEI-CE双功能材料化学结构及表面电荷特性等的影响;研究了hPEI-CE双功能材料对可溶性有机染料、不可溶高岭土悬浮液的吸附能力和絮凝效果;在此基础上,进一步探索了其对工业机械加工废水和丝绸印染废水的脱浊脱色效果。论文研究结果如下:(1)超支化聚乙烯亚胺-纤维素基双功能材料的制备:非均相条件下,采用高碘酸钠将纤维素氧化为二醛纤维素(DAC),然后利用席夫碱反应将hPEI接枝到DAC上,制备具有超支化结构的纤维素基吸附絮凝双功能材料(hPEI-CE)。在合成过程中,通过对高碘酸钠氧化工艺和hPEI接枝工艺的控制,获得了可溶解(s-hPEI-CE)和不可溶解(d-hPEI-CE)的两种hPEI-CE双功能材料;优化工艺条件下,s-hPEI-CE氨基含量为4.02mmol/g,d-hPEI-CE氨基含量为3.85 mmol/g;pH5-12时,s-hPEI-CE和d-hPEI-CE表面Zeta分别分布在-17~44和-35~30.5eV范围,具有可调控的表面电荷特性。(2)超支化聚乙烯亚胺-纤维素基双功能材料的吸附性能研究:以阴离子染料刚果红(CR)和阳离子染料碱性黄28(BY28)为模型,考察吸附时间、温度、吸附剂用量、染料初始浓度等因素对d-hPEI-CE吸附行为的影响。研究表明,d-hPEI-CE对两种染料均具有优异的吸附性能,其对CR和BY28的最大吸附量分别高达2100 mg/g和1860 mg/g,二者的去除率分别达到99%和96.6%;d-hPEI-CE对CR和BY28的吸附行为符合伪二级动力学模型和Langmuir吸附等温线;在此基础上,研究了d-hPEI-CE对刚果红(CR)、碱性黄28(BY28)、亮蓝133(BB 133)、阳离子嫩黄7GL(7GL)、曙红Y(EY)和活性红(RR)等6种染料的吸附效果,发现d-hPEI-CE对不同结构特性的有机染料具有不同的吸附能力,呈现出良好的选择性吸附和智能分离能力。(3)超支化聚乙烯亚胺-纤维素基双功能材料的絮凝性能研究:以高岭土悬浮液为模拟水样,考查絮凝时间、絮凝剂浓度、絮凝剂用量等对三种不同氨基含量s-hPEI-CE的絮凝性能的影响。结果发现,添加3 m L浓度为80 mg/L的s-hPEI-CE时,整个体系的Zeta电位值接近为零,絮凝效果最优,此时高岭土溶液(100 mL)的浊度从490 NTU降低至3.6 NTU;实际工业废水处理发现,s-hPEI-CE对机械加工废水和丝绸印染废水均具有较好的脱浊脱色效果,前者的COD和浊度分别由45 mg/L和4 NTU降至13 mg/L和3.2 NTU,后者的COD和浊度则由118 mg/L和15 NTU降到了37 mg/L和4.6 NTU。因此,本论文所制备的超支化纤维素基吸附絮凝双功能材料具有十分优异的絮凝脱色能力,在工艺废水处理中展现出优异的应用潜能。
[Abstract]:The control and treatment of industrial and agricultural wastewater is an important subject of green sustainable development in the society. In the traditional sewage treatment technology, flocculation and adsorption are the most direct and effective treatment methods for the decolorization of unsoluble pollutants and soluble pollutants. However, there are a wide variety of pollutants in the water body and a single use of some kind of flocculation. The coagulant or adsorbent can not remove all the pollutants to achieve the effect of decolorization and decolorization. It is often necessary to combine the flocculant and adsorbent so as to achieve the discharge or use standard. Therefore, a new type of material with double functions of flocculation precipitation and adsorption decolorization is studied and developed to realize the insoluble and soluble pollution in the wastewater. In this paper, cellulose (CE) and branched polyethyleneimine (hPEI) are used as the main materials to prepare cellulose based adsorbent with hyperbranched structure by molecular design and controllable synthesis. Flocculation dual functional material (hPEI-CE). The effects of grafting technology on the chemical structure and surface charge characteristics of the prepared hPEI-CE dual functional materials were investigated. The adsorption capacity and flocculation effect of hPEI-CE dual functional materials on soluble organic dyes and insoluble kaolin suspension were studied. On this basis, the two functional materials were further explored. The results of the decolorization and decolorization of industrial machined wastewater and silk printing and dyeing wastewater are as follows: (1) preparation of hyperbranched polyethyleneimine - cellulose based dual functional materials: under heterogeneous conditions, cellulose was oxidized to two aldehyde cellulose (DAC) by sodium periodate, and then the hPEI was grafted onto DAC by the Schiff base reaction. The cellulose based flocculating bifunctional material (hPEI-CE) of the hyperbranched structure (hPEI-CE). In the process of synthesis, two kinds of hPEI-CE dual functional materials are obtained by the control of the oxidation process of sodium periodate and the grafting process of hPEI. The content of the s-hPEI-CE amino group is 4.02mmol/g, d-hPEI- under the optimum process conditions. The content of CE amino group is 3.85 mmol/g; when pH5-12, s-hPEI-CE and d-hPEI-CE surface Zeta are distributed in -17~44 and -35~30.5eV, respectively, and have controllable surface charge characteristics. (2) study on Adsorption Properties of hyperbranched polyethyleneimine cellulose based dual functional materials: anionic dye Congo red (CR) and cationic dye alkaline yellow 28 (BY28) as a model The effect of adsorption time, temperature, adsorbent dosage and initial concentration of dye on the adsorption behavior of d-hPEI-CE was investigated. The study showed that d-hPEI-CE had excellent adsorption properties for two dyes, and the maximum adsorption capacity of CR and BY28 was up to 2100 mg/g and 1860 mg/g respectively, and the removal rates of two were 99% and 96.6%, d-hPEI-CE to CR, respectively. The adsorption behavior of BY28 and BY28 was in accordance with pseudo two order kinetic model and Langmuir adsorption isotherm. On this basis, the adsorption effects of d-hPEI-CE on 6 dyes, such as Congo red (CR), alkaline yellow 28 (BY28), bright blue 133 (BB 133), cationic yellow 7GL (7GL), eosin Y (EY) and active red (RR), were investigated. The flocculation property of the hyperbranched polyethyleneimine cellulose based dual functional materials was studied. (3) the flocculation of three kinds of s-hPEI-CE with different amino content, such as flocculating time, flocculant concentration and flocculant dosage, were studied by using kaolin suspension as the simulated water sample. The results showed that when the concentration of 3 m L was 80 mg/L, the Zeta potential value of the whole system was close to zero and the flocculation effect was the best. At this time the turbidity of the kaolin solution (100 mL) decreased from 490 NTU to 3.6 NTU, and the actual industrial wastewater treatment found that s-hPEI-CE had better removal of the mechanical and silk printing and dyeing wastewater. The COD and turbidity of the former were reduced from 45 mg/L and 4 NTU to 13 mg/L and 3.2 NTU, respectively, while the COD and turbidity of the latter decreased from 118 mg/L and 15 NTU to 37 mg/L and 4.6 NTU.. The hyperbranched cellulose based flocculating dual functional materials have excellent flocculation and decolorization ability and were exhibited in the process wastewater treatment. Excellent application potential.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;TB34

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