磁性氧化石墨—壳聚糖复合材料去除废水中有机染料研究

发布时间：2018-04-24 03:05

本文选题：磁性氧化石墨-壳聚糖 + 染料　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：随着国民经济的发展,水环境问题逐渐引起普遍关注。印染废水中含有大量有毒有机污染物、酸碱物质等,成分复杂,性质稳定,可生化性差,阻碍了水环境的正常修复,亟待解决。吸附技术是工业废水处理的传统方法,其中传统吸附剂具有吸附量低、不易分离、二次污染等缺点,新型吸附剂的研发制备为污水处理工艺的进步提供了新的思路。近年来,新型吸附剂石墨烯基复合材料兴起,其富有比表面积大、吸附能力强等特性。本研究制备了易于分离、吸附性能良好的磁性氧化石墨-壳聚糖复合材料(Magnetic Chitosan-Graphene Oxide,MCGO),并分别对酸性染料和碱性染料进行吸附实验,考查其吸附性能及适用条件。在氨基基团与羧基基团的偶联作用下,磁性壳聚糖(Magnetic Chitosan,MCS)呈团聚状无序负载至氧化石墨(Graphene Oxide;GO)表面,合成MCGO复合材料,表面官能团丰富,热稳定性强,附着Fe3O4磁性粒子,磁饱和强度较大,可实现快速分离。MCGO对酸性染料甲基蓝(Methyl Blue,MB)的饱和吸附量为66.43 mg/g,吸附饱和时间为30 h,分阶段进行,符合伪二级动力学模型,符合Langmuir等温吸附模型,为单分子吸附过程。吸附酸性染料过程为放热反应,在酸性条件与低温条件下有较高吸附量。吸附行为是静电吸引作用与范德华力共同作用的结果。以Na OH溶液为脱附剂,溶剂法再生MCGO,循环再生5次后依旧可达原有吸附量的80%。MCGO对碱性染料亚甲基蓝(Methylene Blue,MBL)的饱和吸附量为104.5 mg/g,吸附平衡时间4 h,分阶段进行,符合伪二级动力学模型,符合Langmuir等温吸附模型,材料表面官能团分布均匀。吸附过程由表面扩散和颗粒内部扩散两方面决定。吸附碱性染料为吸热反应,碱性条件与高温条件可促进吸附反应。吸附机理与MCGO吸附酸性染料类似,以静电吸引作用与范德华力为主。以HCl溶液为脱附剂,溶剂法再生MCGO,5次循环周期后,吸附量为原始的70%。从吸附容量、吸附速率角度讲,MCGO吸附碱性染料的效果更优,但MCGO吸附酸性染料的重复利用性更强。MCGO吸附不同种类染料有各自的适用条件,具有广泛的适用性,且操作方便,在实际印染废水的处理应用中具有巨大的潜力。
[Abstract]:With the development of national economy, the problem of water environment has been paid more and more attention. Printing and dyeing wastewater contains a large number of toxic organic pollutants, acid and alkali substances, complex components, stable properties, poor biodegradability, hinders the normal restoration of the water environment, and needs to be solved. Adsorption technology is the traditional method of industrial wastewater treatment, among which the traditional adsorbent has the disadvantages of low adsorption capacity, difficult to separate, secondary pollution and so on. The development and preparation of new adsorbent provides a new way of thinking for the progress of wastewater treatment technology. In recent years, new adsorbent graphene matrix composites have emerged, which have large specific surface area and strong adsorption ability. In this study, magnetic Chitosan-Graphene oxide / chitosan composite material, which is easy to separate and has good adsorption performance, was prepared. The adsorption experiments of acid dyes and basic dyes were carried out, and their adsorption properties and suitable conditions were investigated. Under the coupling action of amino group and carboxyl group, the magnetic chitosan loaded with magnetic Chitosanine onto the surface of Graphene oxide oxide (MCGO) was synthesized. The surface of the composite is rich in functional groups, strong in thermal stability and attached to the Fe3O4 magnetic particles. The magnetic saturation intensity is high, and the saturation adsorption capacity of acid dye methyl blue blue blue MBB is 66.43 mg / g, and the adsorption saturation time is 30 h, which is in accordance with pseudo-second-order kinetic model and Langmuir isothermal adsorption model, and the adsorption capacity is 66.43 mg / g, and the saturation time is 30 h, which is consistent with the pseudo-second-order kinetic model and the Langmuir isothermal adsorption model. It is a monolayer adsorption process. The process of adsorption of acid dyes is exothermic reaction with high adsorption capacity under acidic and low temperature conditions. The adsorption behavior is the result of the interaction of electrostatic attraction and van der Waals force. Using NaOH solution as desorption agent, the solvent method was used to regenerate MCGO.The saturated adsorption capacity of 80%.MCGO, which could still reach the original adsorption capacity, was 104.5 mg / g, and the adsorption equilibrium time was 4 h, and the adsorption equilibrium time was 4 h. It accords with pseudo-second-order kinetic model and Langmuir isotherm adsorption model, and the functional groups on the surface of the material are uniformly distributed. The adsorption process is determined by both surface diffusion and internal particle diffusion. The adsorption of basic dyes is an endothermic reaction, and the conditions of alkali and high temperature can promote the adsorption reaction. The adsorption mechanism is similar to the adsorption of acid dyes by MCGO with electrostatic attraction and van der Waals force. When HCl solution was used as desorption agent, the adsorption capacity was 70% after 5 cycles of solvent regeneration. From the point of view of adsorption capacity and adsorption rate, the adsorption efficiency of basic dyes is better, but the reutilization of MCGO adsorbed acid dyes is stronger. MCGO has its own suitable conditions for adsorption of different kinds of dyes, which has wide applicability and convenient operation. It has great potential in the treatment and application of printing and dyeing wastewater.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X791

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