改性氧化镁复合除氟剂的吸附性能研究
发布时间：2018-07-13 17:08
【摘要】：氟元素对于保证人体的器官和组织正常运行起着至关重要的作用,但氟元素供应不足或过量均会影响人体各项机能指标。因此控制摄入氟的总量对人类健康具有重要意义。人体内的氟大部分是通过长期饮用含氟水获得,而世界上许多国家和地区均出现过饮用水中氟元素超标的问题。目前,吸附法因具有成本低且高效的特点,在饮用水除氟中被人们普遍接受。而研究最多的是对新材料新工艺的探究和对传统材料吸附性能的改进研究。活性氧化镁是一种简单的金属氧化物,可用作除氟材料,但由于其除氟时达到平衡的时间较长且价格稍贵等限制因素较难在实际工程中应用。为了克服MgO的这一局限性并改善其脱氟性能,本实验引入蔗糖做改良剂,经过一系列制备条件的优化得到了氧化镁蔗糖复合除氟剂。Sol-gel法制得氧化镁/蔗糖复合除氟剂的最优化条件:蔗糖氧化镁质量比为5:4,煅烧时间和煅烧温度分别为150min和400℃。本文通过静态批次实验考查了固液比、反应时间、溶液初始p H、原水氟浓度及其他阴离子对MgO-suc吸附剂除氟效果的影响。结果表明:固液比为2g/L,原水氟浓度为10mg/L条件下,反应70min即达到最大吸附量4.74mg/g,且MgO-suc除氟剂对溶液pH有很好的适应性。通过热力学实验及分析结果表明氧化镁/蔗糖的脱氟反应是自发的放热反应,Langmuir吸附等温模型可以较好的描述该除氟过程。对动力学试验数据的模拟结果显示,准二级动力学模型和粒子扩散模型可以较好的描述MgO-suc复合除氟剂的脱氟传质过程。MgO-suc复合除氟剂的反应机理涉及氢键作用。通过动态实验考察了床层质量、进水流量、原水氟浓度、环境温度、pH及共存阴离子对运行效果的影响,并引入了Thomas模型和Yan模型对实验数据做穿透曲线的拟合。本文在理论研究的基础上,结合实际情况,证明了MgO-suc复合吸附剂除氟效果佳,环境适应性好,值得推广应用。
[Abstract]:Fluorine plays an important role in ensuring the normal operation of human organs and tissues, but insufficient or excessive supply of fluorine will affect the function of human body. Therefore, controlling the total amount of fluoride intake is of great significance to human health. Most of the fluoride in human body is obtained by drinking fluorine water for a long time. However, many countries and regions in the world have had the problem of exceeding the standard of fluorine in drinking water. At present, adsorption method is widely accepted in drinking water for its low cost and high efficiency. The research on the new materials and new processes and the improvement of the adsorption properties of the traditional materials are the most studied. Active magnesium oxide is a simple metal oxide, which can be used as a fluorine removal material, but it is difficult to be used in practical engineering because of its long time to achieve equilibrium and the lower price. In order to overcome this limitation of MgO and improve its defluorination performance, sucrose was introduced as modifier in this experiment. After a series of preparation conditions were optimized, the optimum conditions of magnesium oxide / sucrose composite defluorination agent were obtained by Sol-gel method: the mass ratio of magnesium oxide to sucrose was 5: 4, the calcination time and temperature were 150min and 400 鈩，
本文编号：2120125
[Abstract]:Fluorine plays an important role in ensuring the normal operation of human organs and tissues, but insufficient or excessive supply of fluorine will affect the function of human body. Therefore, controlling the total amount of fluoride intake is of great significance to human health. Most of the fluoride in human body is obtained by drinking fluorine water for a long time. However, many countries and regions in the world have had the problem of exceeding the standard of fluorine in drinking water. At present, adsorption method is widely accepted in drinking water for its low cost and high efficiency. The research on the new materials and new processes and the improvement of the adsorption properties of the traditional materials are the most studied. Active magnesium oxide is a simple metal oxide, which can be used as a fluorine removal material, but it is difficult to be used in practical engineering because of its long time to achieve equilibrium and the lower price. In order to overcome this limitation of MgO and improve its defluorination performance, sucrose was introduced as modifier in this experiment. After a series of preparation conditions were optimized, the optimum conditions of magnesium oxide / sucrose composite defluorination agent were obtained by Sol-gel method: the mass ratio of magnesium oxide to sucrose was 5: 4, the calcination time and temperature were 150min and 400 鈩，
本文编号：2120125
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