基于化学手段可控合成稻壳基染料吸附剂的探索

发布时间：2018-11-28 16:52

【摘要】：随着人口和经济的快速增长,环境危机问题已渐渐引起了公众的关注。印染工业的废水已经成为众多环境问题的主要来源之一。其中,亚甲基蓝(MB)作为染料被广泛应用于丝绸,木制品和棉布等。但是,它的污染物由于其毒性不仅恶化水质而且严重影响人类的健康。如今,利用农业废弃物作为原料制备染料吸附剂是一种新的趋势。中国自古就是农业大国,由于人口众多,导致粮食的需求量极大,因此,每年会生产出大量的粮食但是随之也产生了大量的农业废弃物,稻壳就是其中之一。本文主要介绍直接利用稻壳通过低温溶液辅助过程碳化制备出碳硅复合材料,通过一系列化学手段对其进行改性修饰,使其具备优越的吸附效果。主要研究内容如下:1.将稻壳粉末和一定质量分数的硫酸通过低温溶液过程碳化制备出碳硅复合材料(RH-c)。接着将制得的碳硅复合材料与饱和过硫酸铵溶液混合,搅拌反应一定时间,便制备出含有大量含氧官能团的高性能吸附剂(RH-c-ox)。2.利用β-环糊精(β-cd)改性碳化后的稻壳,制备高性能吸附剂。将碳化后的稻壳(RH-c)与一定浓度的β-cd按一定比例混合,包覆一定时间,通过控制环糊精浓度、固液包覆比例和包覆时间,制备出新型稻壳基吸附剂。为了方便吸附剂的回收利用,采用共沉淀法制备出粒径范围在10-20nm的铁核使其点缀在环糊精改性了的吸附剂上使一体化,制备出具有磁性可回收的RH-c/Fe3O4/CD型吸附剂。3.吸附剂的形貌以及表面化学特性通过使用N2-sorption,FTIR,XRD,XPS,SEM,TEM,NMR和VSM等手段进行表征。4.系统地讨论了稻壳基吸附剂对染料亚甲基蓝的吸附性能,并对此过程的动力学、热力学模型进行了研究。
[Abstract]:With the rapid growth of population and economy, environmental crisis has gradually attracted public attention. The wastewater of printing and dyeing industry has become one of the main sources of many environmental problems. Among them, methylene blue (MB) is widely used in silk, wood and cotton as dyes. However, its contaminants not only worsen water quality but also seriously affect human health due to its toxicity. Nowadays, it is a new trend to use agricultural waste as raw material to prepare dye adsorbent. China has been a large agricultural country since ancient times. Because of the large population, the demand for grain is great. Therefore, a large amount of grain will be produced every year, but with it a large amount of agricultural waste has been produced, among which rice husk is one of them. This paper mainly introduces the preparation of carbon-silicon composites by carbonization of rice husks through low-temperature solution assisted carbonization, and modifies them by a series of chemical methods to make them have superior adsorption effect. The main contents are as follows: 1. Carbon-silicon composites (RH-c) were prepared by carbonization of rice husk powder and sulfuric acid in low temperature solution. After mixing the carbon-silicon composites with saturated ammonium persulfate solution and stirring for a certain time, a high performance adsorbent (RH-c-ox) containing a large number of oxygen functional groups (RH-c-ox) was prepared. High performance adsorbent was prepared from carbonized rice husk modified by 尾 -cyclodextrin (尾-cd). A new rice husk based adsorbent was prepared by mixing carbonized rice husk (RH-c) with a certain concentration of 尾-cd and coating for a certain time by controlling the concentration of cyclodextrin, the ratio of solid to liquid coating and the coating time. In order to facilitate the recovery and utilization of the adsorbent, the iron core with the particle size range of 10-20nm was prepared by co-precipitation method, which was embellished on the adsorbent modified by cyclodextrin. A magnetic recoverable RH-c/Fe3O4/CD adsorbent was prepared. The morphology and surface chemical properties of the adsorbent were characterized by means of NMR and VSM. The adsorption properties of rice husk based adsorbents for dye methylene blue were systematically discussed, and the kinetic and thermodynamic models of the process were studied.
【学位授予单位】：大连工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X791;TQ424

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