【作者】 陈继浩；

【导师】 梁广川；

【作者基本信息】 河北工业大学 ， 材料物理与化学， 2006， 硕士

【摘要】 本文针对日益严重的饮用水污染,利用凹凸棒石比表面积大、化学稳定性好、吸附能力强等特点,研究具有去除水中重金属离子和有机污染物、抗菌等多重功能的凹凸棒石复合颗粒的制备技术及其性能。 研究了凹凸棒石复合颗粒的制备技术。通过正交试验研究了主要影响因素增孔剂添加量、热活化温度、盐酸浓度和粘结剂添加量对凹凸棒石复合颗粒吸附Cr⁶⁺和甲基橙性能的影响。确定优化制备的工艺条件是:首先对凹凸棒石用2 mol/L盐酸活化2 h,添加抗菌剂和其他添加剂后对粉体球磨30 min,4wt%粘结剂和2wt%增孔剂溶解后与粉体一起制粒,烘干后,500℃焙烧1.5h。 在优化条件下制备的凹凸棒石复合颗粒对六价铬离子和甲基橙有较好的吸附性能。当铬离子浓度为500μg/L,吸附颗粒添加量为2g/100ml时,吸附率为94%。当pH值为7,颗粒添加量为3g/100ml,甲基橙浓度为100 mg/L时,吸附容量为1.25 mg/g。不同pH值的水溶液经凹凸棒石复合颗粒处理后有趋向于中性的趋势。 对比表面积的研究显示,增孔剂、热活化和酸活化的作用,使凹凸棒石复合颗粒的比表面积和孔径分布发生了较大变化,增加了2 nm、2.5 nm和20 nm孔的分布。扫描电镜的研究显示,改性改善了复合颗粒的微观结构,形成多数凹凸棒石单根晶体交织堆叠的疏松多孔的复合颗粒。X射线研究表明,凹凸棒石复合颗粒的晶体结构在经过改性处理后发生了改变,增加了12.9501 nm的新峰位。采用表面张力仪对接触角和表面能的研究表明,改性增加了凹凸棒石复合颗粒的表面能,原因可能是改性方法增加了吸附中心,吸附作用增强。红外光谱研究显示对甲基橙的吸附主要是物理吸附,有少部分是化学吸附。 抗菌结果显示,当二氧化硅载银抗菌剂的添加量为2wt%时,凹凸棒复合颗粒的抗菌性能较好,6h抗菌的杀菌率达到98.7%。原因可能是,铝盐作为粘结剂和抗菌剂的比例达到了优化。而抗菌剂添加量再增加时,会引起银离子的团聚,从而降低复合颗粒的抗菌性能。更多还原

【Abstract】 This work aim at the serious drinking water pollution, using the attapulgite which have great surface area, chemic stability, good absorbent ability, study the preparing method for compound grains which can absorb the heavy metal, organic pollutions and have anti-bacteria function.The attapulgite compound grains preparation method was studied. Studied the effect of concentration of HC1, the appending quantity of binder and pore former, the temperature of heat treatment to performance of absorbing Cr⁶⁺ and methyl-orange. The optimized preparing method is: firstly, acid activate the attapulgite with 2mol/L HC1, then add the anti-bacterial and other appending agents into the powder, ball the mixture of the powder for 30 min, prepare solution with 4% binder and 2% pore former, prepare grains with the powder and the solution. Drying this grains and bake them at 500℃ for 1.5 h.The compound grains have good absorbent performance on Cr⁶⁺ and methyl-orange. When the concentration of the Cr⁶⁺ is 500Mg/L and the appending quantity is 2g/100ml, the adsorbent percentage is 94%. When the appending quantity is 3g/100ml and the concentration is 100mg/L, the adsorption capacity is 1.2mg/g at pH7. The pH has the trend to pH7 after the water be treated by the attapulgite compound grains.The study to surface area and SEM of compound grains showed that the heat treatment temperature, pore former and acid activating obviously changed the surface area and the pore distribution. The pore volume at 2 nm, 2.5 nm and 20 nm increased. The microstructure of the compound grains was improved. Majority of single fibres pile into a loose and porous grain. The study of X-ray showed that the crystal structure changed after adding pore-former and heat treatment. The grains formed a new peak at d=12.9501 nm. The study of surface free energyshows that above modification increased the surface free energy of the compound grains. The reason that the surface free energy increased is likely the modification increased the absorbent center, then increased the adsorbent performance. The infrared spectra showed that the adsorption on methyl-orange is mainly physical adsorption, and a few chemic adsorption.The anti-bacterial result shows that when the appending percentage of anti-bacterial agent is 2%, the anti-bacterial performance is good, the bacteria killing rate to Escherichia coli reaches 98.7% when the anti-bacterial time is 6 h. The reason that the anti-bacterial performance of this percentage of anti-bacterial agent is good is likely this percentage is the optimum ratio of binder and anti-bacterial agent. But when the percentage of anti-bacteria agent increase continuously, the silver ion will reunite, decrease the anti-bacterial performance.更多还原