【作者】 高姗；

【导师】 魏正贵；

【作者基本信息】 南京农业大学 ， 生态学， 2009， 硕士

【摘要】 氟是人体必需的微量元素之一,它不但维持人体骨骼正常发育,而且可以增进骨骼和牙齿强度,适量的摄入氟对人体健康是有好处的。但是如果摄入量过多会导致一类总称为“氟中毒”的疾病,表现为氟骨病、氟斑牙等等。长期摄入高剂量的氟更可导致骨骼变形、疼痛,关节僵硬、钙化,行走困难,严重者可导致瘫痪。目前,我国仍有几千万人饮用高氟水,对人体健康危害严重。为了探索合理的除氟方法和工艺,本论文对纳米羟基磷灰石(n-HAp)除氟性能进行了系统的研究,分析了n-HAp对氟的吸附规律,同时也考察了骨粉的除氟性能。论文分四个部分：1)沉淀法和溶胶凝胶法制备n-HAp粉体的研究采用沉淀法和溶胶凝胶法合成不同粒度的n-HAp粉体,利用X射线衍射(XRD)、红外光谱(IR)和透射电镜(TEM)对其形貌、晶型结构等各方面的性能进行了表征。结果表明：沉淀法制备的n-HAp为纯相态物质、粒度均匀,其粒度随着制备温度的升高而增大；溶胶凝胶法制备的n-HAp,陈化时间影响其粒度大小,陈化时间越长粒度越大。2)n-HAp粉体修复含氟废水的研究通过实验考察了各因素对氟在n-HAp粉体上吸附效果的影响。考察了用量、F-溶液浓度、溶液pH、搅拌时间、温度、无机盐离子、再生条件等。得出结论为：在反应温度为25℃时,F-初始浓度为5 mg／L,pH为5.0,反应时间为120 min,n-HAp投加量为0.5 g／25 mL,除氟效果较佳。溶液中CO32-的存在对n-HAp吸附F-的竞争作用很大。吸附F-后的n-HAp经过NaOH和H2SO4稀溶液处理后,吸附效果基本恢复,是较为理想的饮水除氟材料。3)不同粒度的n-HAp修复含氟废水的研究本部分实验主要对由沉淀法和溶胶凝胶法分别合成的不同粒度的n-HAp除氟的静态实验做了研究。实验结果表明：沉淀法合成的n-HAp对氟的吸附性能优于溶胶凝胶法合成的纳米粉体；n-HAp对水溶液中F-的吸附与粒度大小有关,纳米粉体除氟效果显著高于体相材料,而粒度较小的纳米粉体除氟效果明显高于粒度较大的纳米粉体。在溶胶凝胶法合成的n-HAp粉体中,陈化时间较短的样品吸附效果优于陈化时间较长的样品。4)骨粉修复含氟废水的研究本部分实验考察单因素对氟在骨粉上的吸附效果的影响。静态实验结果表明：F-初始浓度为10 mg／L时,骨粉用量为0.1 g／25 mL,pH为5.0左右,搅拌时间120 min时,吸附效果较佳；骨粉对含氟废水的去除效果要优于n-HAp；H2O2处理和热处理后的骨粉有机成分降低,H2O2处理后的骨粉对F-的吸附性能有所升高,而热处理后的骨粉吸附性能低于骨粉的吸附性能。骨粉对于饮用水中氟离子的去除具有很高的研究和应用价值。更多还原

【Abstract】 Fluoride is a necessary trace element for human since it plays an important role in bone development as well as bone and tooth strengthening. Proper quantity of fluoride intake are helpful for human, however, excess adsorption will cause a kind of disease called "Fluorosis". Long term of over dose fluoride intake will lead to bone distortion, bone aching, muscle and tendon calcium, walking trouble and even paralysis for severe victims. In China there are several ten millions of people suffer from endemic disease caused by extra intake of fluoride from drinking water. In order to explore the methods of fluoride removal from drinking water, this paper chose nano-hydroxyapatite, and conducted researches on this defluoridation performance, analysised the law of n-HAp’s adsorption of fluoride, and this paper also investigated the defluoridation performance of bone meal.This paper mainly includes four parts as follows:1) Study of preparation of n-HAp powders via precipitation and sol-gel methodDifferent particle sized n-HAp powders were synthesized by the precipitation and sol-gel method. XRD、IR、TEM were used to characterize the different particle sized HAp. Results showed that the samples were pure HAp. The nano-sized HAp was sphere-like and weakly aggregated. Particle sizes of samples increased with annealing temperature. While for the different particle sized HAp synthesized by sol-gel method, the crystal size of the HAp nanopowders increases with the increase of aging time.2) Study on removal of fluoride-containing wastewater onto n-HApsThe affection of factors on adsorption were studied, the influence factors including: adsorbent dose, fluoride concentration, pH, temperature, competitive ions. Got the conclusion was:when the temperature was 25℃, initial fluoride concentration was 5 mg/L, pH was 5.0, adsorbent dose was 0.5 g/25 mL, reaction time was 120 min, the effects was better. The addition of CO32- had effects on the adsorption of fluoride. The adsorbent can be regenerated by NaOH and H2SO4 solution.3) Size-dependent defluoridation properties of n-HApThis part researched the static experiment of synthetic HAp with different particle sizes. Results showed that the adsorption capability of n-HAp synthesized by precipitation was better than that of n-HAp by sol-gel method. Better performance was obtained with smaller particle sized HAp, which presented the higher adsorption efficiency. For the n-HAp by sol-gel method, the smaller the aging time, the better the defluoridation performance.4) Study on removal of fluoride-containing wastewater onto bone mealThe affection of factors on adsorption was studied. The static experiment results showed:Initial fluoride concentration was 10 mg/L, pH was 5.0, adsorbent dose was 0.1 g/25 mL, reaction time was 120 min, the effects was better. It was found that bone meal has a more fluoride adsorption capacity compared to n-HAp. After heat and the acidification treatment, the organic materials were removed and the fluoride removal performance can be noticeably increased after the acidification treatment. Bone meal owns the high value of research and applies for the removal of fluoride in the drinking water.更多还原