硅藻土载银无机膜材料的制备与应用研究

【作者】 张润虎；

【导师】 张若愚；

【作者基本信息】 昆明理工大学 ， 应用化学， 2004， 硕士

【摘要】 无机膜因其热稳定性好，化学稳定性高，孔径均匀，耐压强度大，分离性能好而具有广泛的应用。目前，国内外普遍应用的是氧化铝陶瓷无机膜，虽强度较好，但孔径分布较宽，且孔径因制备工艺不同差异较大，影响了无机膜使用范围。近年来国内外对硅藻土型无机膜已有一定的研究，取得了一定的成绩，但至今还没有找到一种制备这类膜的理想方法。 本文用精选后的腾冲硅藻土来制膜，力求使膜的孔径分布均匀，同时用氧化银来改性硅藻土来改变硅藻土对氨的吸附能力，提高氨／水分离效果。通过正交实验分析方法，确定了硅藻土超声波精选最佳工艺：料浆浓度为15％，酸度为5.25％，超声振荡时间为90min。同时对精选的硅藻土进行了扫描电镜分析和X衍射分析。分析结果表明，精选后的硅藻土孔隙清晰，其主要组成为非晶态SiO₂，同时含有极少量的晶态SiO₂。为了提高硅藻土对氨的吸附能力，制备了纳米级Ag₂O，用其对硅藻土进行改性。电镜检测结果表明，制得的Ag₂O已达到纳米级。 用制得的Ag₂O对硅藻土进行改性，从X衍射图上可以看出，当烧结温度高于300℃时，Ag₂O就会转化为Ag，并与硅藻土结合。用这种材料进行了禽流感病毒吸附灭活实验，结果表明Ag对病毒有明显的灭活作用。然后再用银改性的硅藻土作为膜材料，在陶瓷支撑体上进行浸渍涂膜，烧结后得银改性硅藻土型膜件。制膜过程中得出粘结剂用量及烧结温度和膜孔径的分布关系：粘结剂用量增加，膜的大孔减少，小孔增加；烧结温度增加，大孔增加，小孔减少。后用这种膜件进行了初步的氨／水分离实验。结果表明，经过这种膜分离后氨的脱除率可达75％，而能耗及操作费用低，和其它的氨氮废水脱除法比较有明显的优势。更多还原

【Abstract】 Inorganic membrane is employed in many fields because of its some advantages such as excellent thermal stability, good chemical stability , regular aperture, high anti-pressure and well separability etc. At present, the inorganic membrane whose main component is aluminum oxide is used widely in separate field. Though this membrane has high intensity, its some disadvantages: pockety aperture and different aperture which result from dissimilar technical conditions have a negative influence on its using range. In recent years, some achievements in diatomite inorganic membrane have been acquired through researchers’ study in domestic and oversea. However, it is difficult to find a ideal way to prepare this kind of membrane.In order to obtain pockety aperture, this paper prepares inorganic membrane with choosing diatomite of TengChong. The quality of this choosing diatomite is alterd by adding argentic oxide to improve its sorption capacity of ammonia and separate effect of ammonia water. Diatomite is choosed through the experiments of ultrasonic. The orthogonal experiments is employed to determine the best technical conditions. The following is the best conditions: the content of raw material is15%, the acidity is5.25%, the time of ultrasonic vibration is 90 minutes. The all-around chemical analysis is done also. Furthermore, the choosing diatomite is analysized with SEM and X-ray diffraction. The results show that the choosed diatomite has clear cavity and its component is mainly non-crystal SiO2,as well as a small quantity of crystal SiO2. In order to improve its sorption capacity of ammonia, Ag2O is prepared at nanometer-level and it is used to modify diatomite. . The result of SEM analysis show that the diameter of prepared Ag2O has reached nanometer-level.After the prepared Ag2O modifies the diatomite, the X-ray diffraction figures display that when the sintering temperature is beyond 300 C,the Ag2O will translate into Ag which combine with diatomite. This material is used as bactericide of AIV. The result shows that this material can extinguish AIV. we employ the modified diatomite as the membrane material which impregnate ceramic membrane support to form modifying diatomite membrane. During the process of making membrane, the conclusion is drown: when the amount of adhesive is added, the number of the big poreof membrane decreases while the number of small pore of membrane increases; when the temperature of sintering is added, the number of big pore of membrane increases while the number of small pore of membrane decreases. The primary experiments of ammonia water separation with this diatomite membrane are performed. The results indicate that the content of ammonia in water is decreased 75% though the membrane separation. Compare with other methods of ammonia water separation, this kind of separation has some advantages such as energy consuming and operating expenditure is low.更多还原