二氧化锰改性碳纳米材料吸附废水中镉的技术研究

发布时间：2018-02-28 14:56

本文关键词： 碳纳米管石墨烯 MnO_2 改性吸附镉离子　出处：《宁夏大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前重金属镉离子(Cd2+)的水污染问题受到人们极大的关注。碳纳米材料,尤其是碳纳米管及石墨烯,具有比表面积大,吸附能力强等特点,在高效水处理领域已经展现出良好的发展潜力。本论文将预先处理过的CNTs或GO分散在水中,通过锰盐之间的氧化还原反应,直接一锅法制备出MnO2/CNTs和MnO2/GO两种吸附材料,对两种材料进行FTIR、SEM、XRD、BET等表征,并将其用于含镉废水处理,系统研究了各影响因素对吸附效果的影响规律,优化了吸附分离条件,最后浅析了复合化功效机制。通过对水中Cd2+的吸附试验,系统研究了不同因素等对吸附效果的影响。结果表明,对于MnO2/CNTs而言:当负载量为30%、含镉水的pH为6-8、吸附时间120 min、吸附剂用量为20 mg、样品流速为2.0 mL/min、样晶体积为5 mL时改性的负载Mn02碳纳米管对Cd2+的吸附量最优,去除量最高;对于MnO2/GO而言:当负载量为15%、pH为5-11、吸附时间30 min、吸附剂用量为10 mg、样品流速为2.0 mL/min、样晶体积为5 mL时MnO2/GO对Cd2+的吸附量最优,去除量最高。实验结果还表明它们的吸附量不受溶液中共存离子的影响。平衡吸附等温、吸附动力学和热力学数据分析数据表明:MnO2/CNT和MnO2/GO对Cd2+的吸附比较符合朗缪尔模型,吸附过程为自发、吸热、熵增过程,它们的吸附动力学过程比较符合拟二级动力学模型。最后,综合对比MnO2/CNTs、MnO2/GO对实际含镉废水综合处理效果,结果表明:MnO2/CNTs和MnO2/GO对溶液中Cd2+均具有较强的吸附能力,其中,MnO2/GO吸附材料综合处理能力更强,更加高效。两种材料在含镉废水处理方面均具有广阔的应用潜力。
[Abstract]:At present, the water pollution of heavy metal CD ~ (2 +) has attracted great attention. Carbon nanomaterials, especially carbon nanotubes and graphene, have large specific surface area and strong adsorption capacity. In this paper, pretreated CNTs or go were dispersed in water, and two kinds of adsorption materials, MnO2/CNTs and MnO2/GO, were prepared by direct one-pot method through redox reaction between manganese salts. Two kinds of materials were characterized by FTIR SEMX XRDX BET and used in the treatment of cadmium containing wastewater. The influence of various factors on the adsorption effect was studied systematically, and the adsorption and separation conditions were optimized. Finally, the mechanism of compound effect is analyzed. The effects of different factors on the adsorption efficiency of Cd2 in water are systematically studied. The results show that, For MnO2/CNTs, when the loading amount is 30%, the pH of cadmium water is 6-8, the adsorption time is 120 min, the amount of adsorbent is 20 mg, the flow rate of sample is 2.0 mL / min, and the volume of sample crystal is 5 mL, the adsorbed amount of Cd2 is the best and the removal amount is the highest. For MnO2/GO, the optimal adsorption capacity of MnO2/GO for Cd2 was obtained when the loading amount was 15: 15, the adsorption time was 30 min, the amount of adsorbent was 10 mg, the flow rate of sample was 2.0 mL / min, the sample volume was 5 mL, and the adsorption time was 30 min, the adsorption time was 30 min, the flow rate was 2.0 mL / min, and the volume of sample crystal was 5 mL. The experimental results also show that their adsorption capacity is not affected by coexisting ions in solution. The equilibrium adsorption isotherm, adsorption kinetics and thermodynamic data show that the adsorption of Cd2 by MnO2/GO and MNO _ 2 / CNT accords with Langmuir model. The adsorption process is spontaneous, endothermic and entropy increasing, and their adsorption kinetic processes are in accordance with the pseudo-second-order kinetic model. Finally, the comprehensive treatment effects of MnO2 / CNTsNMnO2 / go on actual wastewater containing cadmium are compared. The results show that both MnO2/GO and% MNO _ 2 / CNTs have strong adsorption capacity for Cd2 in solution, and the adsorption materials of MNO _ 2 / go are more efficient and more efficient. Both of them have wide application potential in the treatment of cadmium wastewater.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O647.3;X703

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