谷壳纤维素的改性及其对重金属离子吸附性能的研究

发布时间：2018-01-01 23:17

  本文关键词：谷壳纤维素的改性及其对重金属离子吸附性能的研究　出处：《湖南师范大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 谷壳 化学改性 吸附性能 重金属吸附

【摘要】：随着现代科学技术的迅速发展,工业污染已经成为现如今急需解决的问题,尤其是工业污染中重金属废水的污染问题。如何降低重金属废水对水体和土壤造成的危害,是环境保护工作者目前面临的重大问题。目前,重金属处理技术有化学沉淀法、絮凝法、离子交换法、电催化氧化法、膜分离技术和吸附法等。这些处理方法中生物吸附法具有基体材料廉价易得、来源广泛、吸附有效环保等优点,其中农林废弃物更是成为基体材料选择的研究热点。本文选用农林废弃物谷壳为原料,将粉碎后的谷壳碱化处理后,通过环氧化、氨基乙酸化和氯乙酸化、酯化、胺化制备了两种对重金属有吸附作用的吸附材料。采用红外光谱分别对两种吸附材料改性前后的结构进行表征,通过静态吸附实验,考察了溶液p H、吸附时间和溶液初始浓度对谷壳改性材料吸附性能的影响,并根据其吸附行为进行吸附动力学和吸附等温线拟合。吸附动力学拟合结果表明,亚氨基二乙酸谷壳纤维素(IDACC)和酰胺基谷壳纤维素(CMCA)吸附Cu~(2+)的动力学模型都符合准二级动力学,反应速率的控制步骤是化学反应;吸附等温线拟合结果表明,IDACC和CMCA对Cu~(2+)的吸附都符合Langmuir等温吸附,且都属于单分子层吸附。在研究吸附Cu~(2+)模拟废水的基础上,对实际废水进行吸附实验,考察了所制备的两种改性材料在实际应用中的可行性。实验结果表明废水的pH对吸附效果有一定的影响,废水pH值为8时CMCA吸附效果最好,而废水pH值为6-7时IDACC吸附效果好。当IDACC的投加量为2g时,废水中所含重金属离子的浓度都达到排放标准,而CMCA在除了Cd~(2+)之外,投加量为0.7g时其他三种重金属离子含量达到排放标准。CMCA和IDACC这两种材料对重金属离子的吸附热效应完全不同,CMCA与重金属离子之间的吸附作用是放热过程,IDACC与重金属离子之间的吸附作用是吸热过程。经过5次再生实验,IDACC呈现出良好的再生性能,重金属离子去除率能达到78%以上,而CMCA对四种重金属的再生性能没有IDACC的性能好,特别是再生后对Cd~(2+)的吸附性能表现出很差的效果。因此,IDACC更适合进行实际推广应用。
[Abstract]:With the rapid development of modern science and technology, industrial pollution has become an urgent problem now, especially the problem of heavy metal pollution in industrial wastewater pollution. How to reduce the harm of heavy metal wastewater on water and soil caused by the major problems of environmental protection workers now face. At present, there are chemical precipitation, flocculation heavy metal processing technology the ion exchange method, electro catalytic oxidation, membrane separation and adsorption. Biosorption of these approaches is the matrix material is cheap and easy to get a wide range of sources, environmental protection and other advantages of effective adsorption, including agricultural and forestry wastes have become a research focus in the matrix material selection. This paper use agricultural waste rice husk as raw material, crushing after the hull alkalization, epoxidation, amino acid and chloroacetic acid, esterification, amination of two kinds of adsorption of heavy metals by suction Attached material. By using infrared spectroscopy of two kinds of adsorption materials before and after the structure was characterized by static adsorption experiments, the effects of the solution P H. The effects of adsorption time and initial concentration of solution on the adsorption properties of modified materials of rice husk, and according to the adsorption kinetics and adsorption isotherm fitting the adsorption behavior. The adsorption kinetics of the fitting results show that the imino two acetic acid (IDACC) and rice husk cellulose amide husk cellulose (CMCA) Cu~ (2+) adsorption kinetic model with quasi two order kinetics, the reaction rate controlling step is chemical reaction; adsorption isotherm fitting results show that the IDACC and CMCA of Cu~ (2+) adsorption accords with Langmuir isothermal the adsorption, and belongs to the single molecular layer adsorption. The adsorption of Cu~ (2+) on the basis of simulated wastewater, the wastewater was investigated by adsorption experiment, preparation of two kinds of modified materials in practical application The feasibility of wastewater. The experimental results show that the pH has some influence on the adsorption effect, wastewater pH value is CMCA the best adsorption of 8, while the pH value of wastewater is 6-7 IDACC good adsorption effect. When the dosage of IDACC was 2G, the concentration of heavy metal ions contained in wastewater can reach the discharge standard, in addition to Cd~ and CMCA (2+), the dosage of 0.7G and other three kinds of heavy metal ion content reached the emission standard.CMCA and IDACC these two kinds of material thermal effect of adsorption of heavy metal ions on different adsorption between CMCA and heavy metal ions is an exothermic process, the adsorption between IDACC and heavy metal ions is endothermic. After 5 times of regeneration experiments, IDACC showed good regeneration performance, heavy metal ion removal rate can reach above 78%, and the regeneration performance of CMCA to four kinds of heavy metals is not IDACC good performance, especially after the regeneration of Cd~ (2+). The adsorption performance shows a poor effect. Therefore, IDACC is more suitable for practical application.

【学位授予单位】：湖南师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O636.11
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本文编号：1366647