本文選題：納米氟磷灰石 + 無定形磷酸鈣��； 參考：《南京師范大學(xué)》2012年碩士論文

【摘要】：氟是人體必需的微量元素之一,維持人體骨骼正常發(fā)育,增進(jìn)骨骼和牙齒強度。如果攝入量過多會導(dǎo)致一類總稱為“氟中毒”的疾病,長期攝入高劑量的氟更可導(dǎo)致骨骼變形、關(guān)節(jié)僵硬、鈣化,行走困難,嚴(yán)重者可導(dǎo)致癱瘓。目前,國內(nèi)外對納米羥基磷灰石(nHAP)去除氟污染的理論研究與實際應(yīng)用均較多,但是關(guān)于納米氟磷灰石(nFAP)與無定形磷酸鈣(ACP)治理氟污染鮮有報道,尤其是ACP除氟,以及施加低分子量有機酸對ACP的除氟效果影響還未見報。因此本文主要研究nFAP與ACP的除氟效果,以及施加低分子量有機酸對ACP的除氟影響。 論文分四個部分： (1)沉淀法制備納米氟磷灰石(nFAP)及無定形磷酸鈣(ACP)的研究 通過X射線衍射(XRD)、紅外光譜(IR)和透射電鏡(TEM)對其形貌、晶型結(jié)構(gòu)等方面的性能進(jìn)行了表征。結(jié)果表明沉淀法制備的nFAP均為顆粒均勻、純相態(tài)的物質(zhì)。 (2)納米氟磷灰石的除氟實驗 本實驗通過考察三種材料(nFAP, nFHAP, nHAP)用量、F-溶液濃度、溶液pH、攪拌時間、溫度、再生條件,對比三種材料除氟效果。并且運用Freundlich和Langmuir等溫吸附方程及一級動力學(xué)和二級動力學(xué)方程進(jìn)行擬合,此外還計算了熱力學(xué)函數(shù)AG°、△S°、ΔH°,并初步探討了可能的吸附機理。實驗結(jié)果表明,nFAP與nHAP的除氟機理主要為氫鍵吸附,nFAP與nHAP的除氟效果相當(dāng),nFAP的再生能力強于nHAP,所以nFAP可以用于含氟廢水的處理。 (3)ACP的除氟實驗 本實驗通過考察三種材料(ACP, ACP-nHAP, nHAP)用量、F-溶液濃度、溶液pH、攪拌時間、溫度條件,對比三種材料的除氟效果。實驗結(jié)果表明,在pH5或是溫度高于30℃,ACP的除氟效果明顯好于nHAP,但是pH5時,其吸附效果不如nHAP。得出結(jié)論：當(dāng)材料的粒徑越小,除氟效果越好,但是當(dāng)粒徑達(dá)到無定形狀態(tài),其除氟效果受條件影響,當(dāng)溫度較高或是pH較低,無定形狀態(tài)的除氟效果優(yōu)于納米級羥基磷灰石。 (4)施加低分子量有機酸對ACP除氟能力的影響 本實驗選擇了草酸、檸檬酸蘋果酸作為低分子量有機酸(LMWOAs)的代表�？疾煸诓煌珹CP加入量、溶液pH值、氟初始濃度、反應(yīng)時間、反應(yīng)溫度等條件下,LMWOAs對ACP除氟能力的影響。得到結(jié)論三種有機酸均促進(jìn)ACP的除氟能力,其增強程度為檸檬酸草酸蘋果酸。
[Abstract]:Fluorine is one of the essential trace elements to maintain the normal development of human skeleton and enhance the strength of bone and teeth. If too much intake leads to a class of diseases known as fluorosis, long-term intake of high doses of fluoride can lead to bone deformation, joint stiffness, calcification, difficulty in walking, and severe paralysis. At present, there are many theoretical studies and practical applications of nano-hydroxyapatite (nHAP) in fluoride removal at home and abroad. However, there are few reports on the treatment of fluoride pollution by nano-fluoropatite (nFAP) and amorphous calcium phosphate (ACP), especially on the removal of fluoride by ACP. The effect of low molecular weight organic acid on the defluorination of ACP has not been reported. Therefore, the defluorination effect of nFAP and ACP and the effect of low molecular weight organic acid on the defluorination of ACP were studied in this paper. The thesis is divided into four parts: (1) Nano-fluoroapatite (nFAP) and amorphous calcium phosphate (ACP) were prepared by precipitation method. The morphologies of nano-fluorapatite (nFAP) and amorphous calcium phosphate (ACP) were investigated by X-ray diffraction (XRD), infrared spectroscopy (IR) and transmission electron microscopy (TEM). The properties of crystal structure were characterized. The results show that the nFAP prepared by precipitation method is homogeneous in particle size and in pure phase. (2) the experiment of fluorination of nano-fluorapatite was carried out. The concentration of F- solution, pH of solution, stirring time of three kinds of materials (nFAP, nFHAP-, nHAP) were investigated. Temperature, regeneration condition, contrast three kinds of material to remove fluorine effect. Freundlich and Langmuir isothermal adsorption equations and first-order and second-order kinetic equations were used to fit the equation. In addition, the thermodynamic functions AG 擄, S 擄, 螖 H 擄were calculated, and the possible adsorption mechanism was preliminarily discussed. The experimental results show that the mechanism of defluorination between nFAP and nHAP is that the hydrogen bond adsorption of nFAP and nHAP is equivalent to the regeneration ability of nFAP than nHAP.Therefore, nFAP can be used in the treatment of fluorine-containing wastewater. (3) the defluorination experiment of ACP is carried out. The concentration of F- solution in three kinds of materials (ACP, ACP-nHAP, nHAP) was investigated. The pH of the solution, stirring time, temperature conditions, the comparison of the three materials of fluoride removal effect. The experimental results show that the defluorination effect of ACP at pH 5 or above 30 鈩，

本文編號：2093062