改性活性碳纤维处理低浓度氨氮废水研究

发布时间：2018-04-04 15:22

  本文选题：氨氮废水处理　切入点：活性碳纤维　出处：《北京化工大学》2015年硕士论文

【摘要】：本文主要研究了活性碳纤维的改性方法及条件,以及改性后活性碳纤维在不同条件下对低浓度氨氮废水的静态吸附及动态吸附效果,并对吸附后的改性活性碳纤维样品进行了再生方法研究。首先,通过实验考察了几种常用改性方法对活性碳纤维改性效果的影响,发现硝酸和氢氧化钠联合改性的活性碳纤维样品能有效去除水中低浓度的氨氮。随后又研究了在不同浓度、温度和时间下硝酸和氢氧化钠的改性效果,探寻较适宜的改性条件。其次,本文还研究了改性活性碳纤维样品的氨氮去除率随着时间、温度、初始氨氮浓度、投加量、溶液pH以及共存阳离子等因素的影响,确定了较适宜的吸附条件；通过研究动态吸附实验,绘制了在不同停留时间下的动态吸附曲线。同时对改性活性碳纤维吸附氨氮的过程进行了动力学及热力学研究,通过Langmuir吸附等温式模拟算出最大吸附能力为19.61 mg·g-,并且Frundlich模型拟合结果显示改性活性碳纤维容易吸附水中的氨氮；动力学拟合结果表明吸附过程符合准二级动力学方程,属于内扩散控制过程；热力学参数表明是吸附过程是自发、吸热和熵增加的过程。根据SEM、BET、FIRT、Boehm以及质量滴定等表征手段,推断活性碳纤维的改性及吸附氨氮的机理。本文对吸附饱和后的活性碳纤维进行了再生方法研究,通过对在常温条件下不同浓度的盐酸、氢氧化钠和硫酸钠溶液再生效果对比发现,0.1 mol·L-1的氢氧化钠溶液能有效再生饱和吸附的活性碳纤维。并且进行了蒸汽再生效果研究,发现使用0.1 mol·L-1氢氧化钠浸泡后,再用130℃的水蒸气再生解吸率能达到98%以上。通过动态吸附柱穿透吸附量对比研究水蒸气再生效果,发现五次再生后吸附剂的穿透吸附量基本保持不变,说明改性活性碳纤维能有效地去除废水中的低浓度氨氮,并且再生效果良好,具有良好的工业应用前景。
[Abstract]:In this paper, the modification methods and conditions of activated carbon fiber were studied, and the static and dynamic adsorption effects of modified activated carbon fiber on low concentration ammonia nitrogen wastewater under different conditions were studied.The regeneration method of modified activated carbon fiber after adsorption was studied.Firstly, the effect of several modification methods on the modification effect of activated carbon fiber was investigated experimentally. It was found that the sample of activated carbon fiber modified by nitric acid and sodium hydroxide could effectively remove ammonia nitrogen from water with low concentration of ammonia.Then the modification effects of nitric acid and sodium hydroxide at different concentration, temperature and time were studied.Secondly, the effects of time, temperature, initial concentration of ammonia nitrogen, solution pH and co-existing cations on the removal rate of ammonia nitrogen of modified activated carbon fiber samples were studied, and the suitable adsorption conditions were determined.By studying the dynamic adsorption experiments, the dynamic adsorption curves at different residence times were drawn.At the same time, the kinetics and thermodynamics of the adsorption of ammonia nitrogen by modified activated carbon fiber were studied.The maximum adsorption capacity is 19.61 mg / g by Langmuir isotherm simulation, and the results of Frundlich model fitting show that the modified activated carbon fiber is easy to adsorb ammonia nitrogen in water, and the kinetic fitting results show that the adsorption process accords with the quasi-second-order kinetic equation.The thermodynamic parameters indicate that the adsorption process is spontaneous, endothermic and entropy increasing.The modification of activated carbon fiber and the mechanism of adsorption of ammonia nitrogen were inferred according to the characterization of SEMBETFITT Boehm and mass titration.In this paper, the regeneration method of adsorbed saturated activated carbon fiber was studied, and different concentrations of hydrochloric acid at room temperature were studied.The comparison of regeneration effect between sodium hydroxide solution and sodium sulfate solution shows that 0.1 mol L -1 sodium hydroxide solution can effectively regenerate saturated activated carbon fiber.The effect of steam regeneration was studied. It was found that after soaking with 0.1 mol L-1 sodium hydroxide, the desorption rate of steam regeneration was over 98% at 130 鈩，

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