• 关键词：纳米Fe₂O₃  纳米SiO₂  环氧树脂  石英砂改性  表面负载量  附着强度  形态学

• 基金项目：国家自然科学基金(No.51108094);广东省科技计划项目(No.2012B030900003)

• 李冬梅
• 广东工业大学土木与交通工程学院, 广州 510006

• 庞治星
• 广东工业大学土木与交通工程学院, 广州 510006

• 赵向阳
• 佛山水业集团高明供水有限公司, 佛山 528500

• 李国浩
• 广东工业大学土木与交通工程学院, 广州 510006

• 刘贝
• 广东工业大学土木与交通工程学院, 广州 510006

• 秦梓源
• 华南师范大学附属中学国际部, 广州 510630

• 李绍秀
• 广东工业大学土木与交通工程学院, 广州 510006

• 摘要：以普通石英砂滤料为原材料,纳米Fe₂O₃、纳米SiO₂为改性剂,环氧树脂为粘结剂,表面负载量和附着强度为评价指标,通过正交试验与固定因素不同水平连续性试验等方法,制备了两种纳米氧化物改性石英砂(Nano-oxide coated sand,Nano-OCS).同时,研究了不同制备因素对Nano-OCS表面氧化铁负载量和附着强度的影响,并探讨Nano-OCS制备工艺的最佳优化条件.结果表明,水浴加热过程对改性剂和粘结剂进行慢速搅拌,最佳转速为50 r·min^-1,时间为45 min,烘干时间1 h,温度(120±5)℃,纳米Fe₂O₃(65.8 g·L^-1)与未改性石英砂(RQS)的最佳投加比(体积质量比,下同)为C=0.23 mL·g^-1,改性剂环氧树脂(99%)溶液与RQS的最佳投加比为C₁=0.035 mL·g^-1,纳米SiO₂(10 g·L^-1)与RQS 的最佳投加比为C₂=0.17 mL·g^-1,在最优条件下制备的样品负载量和有机物吸附率均达到92%.投加过量时,有机物吸附率明显减小.与传统的低温碱性沉积法或高温煅烧制得的Nano-OCS相比,加入了粘结剂环氧树脂,用低温水浴固化的方法所制得的Nano-OCS,负载量提高了约8倍,脱附率降低70%以上.本法采用无添加剂的粘结剂,表面改性后不会对水体产生二次污染.

• Abstract：The nano-iron oxide and nano-silicon oxide coated sand (Nano-OCS) are prepared with ordinary quartz sands as the raw material, nano-Fe₂O₃ and nano-SiO₂ as the modifiers, and epoxy resin as the adhesive agent. By using the orthogonal test method, morphological properties analysis and semi-quantitative analysis method by EDS, effects of different factors on surface loading and adherent strength of nano-OCS are analyzed. These factors include stirring frequency N, dosage ratio of nano-Fe₂O₃, nano-SiO₂ and epoxy resin, drying temperature T, time t, appearance of nano-OCS, etc. The optimum preparation conditions are obtained. In the process of water bath heating, modifiers and binders are mixed at a slow stirring speed, with the rotating speed of 50 r·min^-1 for 45 min, drying time of 1 hour with temperature at 120℃±5℃. The optimal dosage ratios of nano-Fe₂O₃ (65.8 g·L^-1), the epoxy resin solution 99%, and nano-SiO₂ (10 g·L^-1) to raw quartz sand (RQS) is 0.23 mL·g^-1, 0.035 mL·g^-1 and 0.17 mL·g^-1, respectively. Both surface loading capacity and adsorption rate of Nano-OCS to organic mattress can be up to 92%. When the dosage is excessive, the adsorption rate is significantly reduced. As compared with Nano-OCS prepared by the alkaline deposition method at low temperature (T≤110℃) and Nano-OCS which is prepared by calcining at high temperature (T≈300℃), the loading capacity of Nano-OCS prepared by the addition of binder epoxy resin and the low-temperature water bath curing method increases by 8 times approximately, and the desorption rate decreases by more than 70%. The preparation method takes the binder without additives thus secondary pollution of Nano-OCS can be avoided.

• Key words：nano-iron oxide  nano-silicon oxide  epoxy resin  modification  surface loading  adherent strength  morphology

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