【作者】 张莉；

【导师】 冯流；

【作者基本信息】 北京化工大学 ， 环境科学， 2009， 硕士

【摘要】 零价铁是一种廉价却简单有效的脱氯剂,与一般的铁颗粒相比,纳米零价铁由于其超微粒径和巨大的表面积,能更有效的转化多种环境污染物,反应活性更大。但是因为纳米铁易氧化、易团聚,限制了它的广泛利用。本文以粘土材料作为载体,达到提高纳米铁稳定性,进而拓宽其应用范围的目的。论文以钠基蒙脱土为原料,确定了利用离子交换法合成了纳米铁/粘土杂化材料的具体制备方法和操作条件。通过X射线衍射(XRD)、透射电子显微镜(TEM)等分析检测手段,表征了杂化材料的微观结构、晶粒度等特征,并通过邻氯苯酚降解实验考查纳米铁/粘土杂化材料的降解性能。结果表明,在制备材料的过程中,离子交换时的浸泡时间、浸泡比例均有导致材料存在最佳性能的最佳值。离子交换过程中,浸泡比例为2.50mmol/g,交换3d效果最好。通过XRD和TEM检测可知,制得材料中所含铁为单质铁,在40-60nm之间,外形以球形为主,均匀地负载于粘土上。材料较为稳定,无需特殊保存即可稳定存放,无明显氧化现象。在相同工艺条件下,纳米铁/粘土杂化材料对邻氯苯酚的去除能力与纳米铁相近,去除率高达98.4%,且放置30d后,其降解率为96.7%,降解效率无明显降低。更多还原

【Abstract】 Zero-valent iron is a cheap but simple and effective antichlor. The amount of nano- iron is much less than ordinary iron since it is more active when used as antichlor. However, nano-iron is such an ultra fine particle and has enormous surface area, which makes it easy to oxidize, so that nano-iron is hard to preserve. When nano-iron agglomerates, it usually reduces the efficiency of this antichlor. All these factors restrict its further use.By the ion-exchange process, nano-iron/clay hybrid materials have been prepared.Transmission electronic microscopies (TEM), X-ray diffraction (XRD) are used to observe the microstructure and properties of the products are tested by O-chlorophenol degradation experiments.The results show that most of the nano-iron in the products is between 40-60nm and in ball shape, homodisperse in the clay and rarely aggregation. The products can stable without oxidation when preserved in ordinary conditions. And 30 minutes later after being added to O-chlorophenol solution, the degradation rate can reach as high as 98.4%, which shows advanced dechlorination properties.更多还原