【作者】 魏林；

【导师】 姜修道；

【作者基本信息】 长安大学 ， 材料学， 2008， 硕士

【摘要】 水是人类赖以生存的三大要素之一,但是随着经济的快速增长,工农业的快速发展,水资源正在急剧消耗。此外,更让人担忧的是随之而来的水体严重污染问题,这直接威胁人类和其它生物的生命健康,破坏整个生态系统的稳定性。水体中的污染物种类繁多,如重金属污染物、有机污染物、氰化物、硫化物、酸碱盐污染物。其中重金属以其对人体和动植物等严重的毒害性和难处理性,成为水体中具有严重危害性的无机污染物。对重金属污染物的处理方法很多,其中利用天然矿物材料作吸附剂处理重金属成为焦点。目前,人们已利用天然层状硅酸盐矿物处理重金属污染物,并取得良好的实验结果。滑石粉作为一种不带层电荷的层状硅酸盐矿物,具有优良的化学稳定性,对油脂、颜料、药剂和溶液里的杂质都有极大的吸附能力。因此本文研究了滑石对水中重金属Cu²⁺、Pb²⁺、Cd²⁺的吸附效果;分别讨论滑石用量、溶液pH值、吸附温度和吸附时间对重金属离子去除效果的影响;用Langmuir和Freundlich吸附等温线描述滑石对吸附质的吸附特性;利用X衍射分析和红外光谱分析,初步探讨了滑石对重金属离子的吸附机理。通过实验表明,滑石对水溶液中的重金属Cu²⁺、Pb²⁺、Cd²⁺具有良好的吸附效果,三种重金属离子的等温线均符合Langmuir和Freundlich的吸附等温线,尤其与Freundlich吸附等温式的符合情况更好。当三种重金属初始浓度相同时（100mg/L）,滑石对Cu²⁺、Pb²⁺、Cd²⁺吸附能力的顺序为Pb²⁺> Cu²⁺> Cd²⁺。影响重金属Cu²⁺去除率的主要因素有滑石用量、溶液pH值、吸附时间和吸附温度。其中滑石用量为2g时,对Cu²⁺的去除率为45%,用量为10g时Cu²⁺的去除率为97.5%;pH值为3时Cu²⁺的去除率仅为59%,而当pH增加值7时,去除率迅速增加至99.87%,可见pH值对Cu²⁺的去除率影响显著;滑石对Cu²⁺的去除率随吸附时间的不断增加而增大,7h后基本达到吸附平衡状态,去除率为98.4%;滑石吸附Cu²⁺的最佳温度范围为60⁷0℃。影响重金属Pb²⁺以及高浓度Cd²⁺去除率的主要因素为溶液pH值。当溶液pH值小于4时对Pb²⁺的去除率为81%,而pH值超过4时去除率显著增大至98.89%;当溶液pH值在3⁶时,滑石对Cd²⁺（100mg/L）的去除率最大仅为22%,而pH增大至7时,去除率达到99.97%。溶液pH值和吸附时间是影响滑石吸附处理低浓度Cd²⁺的主要因素。pH值在3⁷时,滑石对Cd²⁺的去除率从97.2%增大至99.96%,之后随着pH的进一步增大Cd²⁺去除率变化缓慢;滑石吸附处理Cd²⁺的最佳吸附时间为5h且此时基本达到吸附平衡,去除率为99.1%。吸附重金属Cu²⁺的滑石的X衍射和傅立叶变换红外光谱表明滑石对重金属Cu²⁺的吸附中存在表面OH-的络合吸附和表面物理吸附,但使用X衍射和傅立叶变化红外光谱这两种手段来研究滑石对Pb²⁺和Cd²⁺吸附作用时,效果不理想,因此有必要采用其它手段研究滑石对重金属离子的吸附机理。更多还原

【Abstract】 Water is vital factor on which human being depend to exist. Water symbolizes the civilization of humans. With the rapid development of economy, the water resource is consumed rapidly. Furthermore, the problem of water pollution has been becoming more and more serious. It is threat to huaman and anmimals health and destroies the stabilization of the whole ecosystem. There aew lots kinds of contaiminations in water, such as Heavy metal, Organic Pollutant , Cyanide , sulpHide et al. Among this, Heavy metals are serious inorganic contamination in water according to its property of poison to huaman and propagation, and they are hardly to deal with. Generally, heavy metals are come from the industry pollution.So, People use many ways to uptake the heavy metals and using natural silicates to solve the pollution have being become more and more popular. At present, people use layer silicates to adsorb the heavy metal from wastewater and found that they have excellent adsorptive performance. Taclum powder is a kind of layer silicate. It has excellent adsorption to deal with lipin, pigment, medicament or other impurity in water. So, I’d like to study the adsorption of talcum to sorb the heavy metals(Cu²⁺,Pb²⁺,Cd²⁺)from water and studied the relationship between experiment factors and adsorbent property. The Langmuir and Freundlich isotherm are used to describe the performance of absorption. In addition, Using the X-Ray diffraction and Fourier transform infrared spectrometry, the adsorbent law and mechanism is studied in the course of adsorption.The experiment results showed that Talcum has good adsorption to sorb heavy metal, such as Cu²⁺,Pb²⁺,Cd²⁺. The adsorption isotherms of Cu²⁺,Pb²⁺,Cd²⁺ fit the Langmuir and Freundlich equation, but fit the Freundlich well. The heavy metals having the same initial dye concentration, the adsorption property of talcum to solve Cu²⁺,Pb²⁺,Cd²⁺ is Pb²⁺> Cu²⁺> Cd²⁺.Talcum amount, initial pH of solution, adsorption time and adsorption temperature are the major factors to effect the adsorption effect of Cu²⁺. When the talcum amout arise from 2g to 10, the adsorption removal rate can be obtained from 45% to 97.5%. and the pH of solution is a major factor. The pH of solution is 3, the removal rate is 59%; while it is 7, the removal rate is 99.87%. and the best temperature is 60⁷0℃。And pH of solution is a major factor to effect the removal rate of Pb²⁺ and Cd²⁺（100mg/L）. when the pH of solution is lower than 4, the removal rate of Pb²⁺ is 81%. But the pH is higher than 4, the rate is 98.89%. According to Cd²⁺（10mg/L）, when the pH of solution range from 3 to 6, the removal rate of Cd²⁺ range from 22% to 99.97%. While the pH of solution and the adsorption time is major factor to solve the Cd²⁺ which concentration is 10mg/L. pH of solution range from 3 to 7, the removal rate of Cd²⁺ range from 97.2% to 99.96%. And the best adsorption time is 5 hours. Then the removal rate is 99.1%.And the results of XRD and FTIR of the Talcum powder which adsorbs the Cu²⁺ shows that the Talcum powder adsorb heavy meatal ion mainly by means of surface compound adsorption and pHysics adsorption. But the XRD and FTIR can not express the whole adsorption law. So we need to choose another way to study the adsorbent law and mechanism of Talcum.更多还原