【摘要】：氟元素對(duì)于保證人體的器官和組織正常運(yùn)行起著至關(guān)重要的作用,但氟元素供應(yīng)不足或過量均會(huì)影響人體各項(xiàng)機(jī)能指標(biāo)。因此控制攝入氟的總量對(duì)人類健康具有重要意義。人體內(nèi)的氟大部分是通過長(zhǎng)期飲用含氟水獲得,而世界上許多國(guó)家和地區(qū)均出現(xiàn)過飲用水中氟元素超標(biāo)的問題。目前,吸附法因具有成本低且高效的特點(diǎn),在飲用水除氟中被人們普遍接受。而研究最多的是對(duì)新材料新工藝的探究和對(duì)傳統(tǒng)材料吸附性能的改進(jìn)研究�；钚匝趸V是一種簡(jiǎn)單的金屬氧化物,可用作除氟材料,但由于其除氟時(shí)達(dá)到平衡的時(shí)間較長(zhǎng)且價(jià)格稍貴等限制因素較難在實(shí)際工程中應(yīng)用。為了克服MgO的這一局限性并改善其脫氟性能,本實(shí)驗(yàn)引入蔗糖做改良劑,經(jīng)過一系列制備條件的優(yōu)化得到了氧化鎂蔗糖復(fù)合除氟劑。Sol-gel法制得氧化鎂/蔗糖復(fù)合除氟劑的最優(yōu)化條件:蔗糖氧化鎂質(zhì)量比為5:4,煅燒時(shí)間和煅燒溫度分別為150min和400℃。本文通過靜態(tài)批次實(shí)驗(yàn)考查了固液比、反應(yīng)時(shí)間、溶液初始p H、原水氟濃度及其他陰離子對(duì)MgO-suc吸附劑除氟效果的影響。結(jié)果表明:固液比為2g/L,原水氟濃度為10mg/L條件下,反應(yīng)70min即達(dá)到最大吸附量4.74mg/g,且MgO-suc除氟劑對(duì)溶液pH有很好的適應(yīng)性。通過熱力學(xué)實(shí)驗(yàn)及分析結(jié)果表明氧化鎂/蔗糖的脫氟反應(yīng)是自發(fā)的放熱反應(yīng),Langmuir吸附等溫模型可以較好的描述該除氟過程。對(duì)動(dòng)力學(xué)試驗(yàn)數(shù)據(jù)的模擬結(jié)果顯示,準(zhǔn)二級(jí)動(dòng)力學(xué)模型和粒子擴(kuò)散模型可以較好的描述MgO-suc復(fù)合除氟劑的脫氟傳質(zhì)過程。MgO-suc復(fù)合除氟劑的反應(yīng)機(jī)理涉及氫鍵作用。通過動(dòng)態(tài)實(shí)驗(yàn)考察了床層質(zhì)量、進(jìn)水流量、原水氟濃度、環(huán)境溫度、pH及共存陰離子對(duì)運(yùn)行效果的影響,并引入了Thomas模型和Yan模型對(duì)實(shí)驗(yàn)數(shù)據(jù)做穿透曲線的擬合。本文在理論研究的基礎(chǔ)上,結(jié)合實(shí)際情況,證明了MgO-suc復(fù)合吸附劑除氟效果佳,環(huán)境適應(yīng)性好,值得推廣應(yīng)用。
[Abstract]:Fluorine plays an important role in ensuring the normal operation of human organs and tissues, but insufficient or excessive supply of fluorine will affect the function of human body. Therefore, controlling the total amount of fluoride intake is of great significance to human health. Most of the fluoride in human body is obtained by drinking fluorine water for a long time. However, many countries and regions in the world have had the problem of exceeding the standard of fluorine in drinking water. At present, adsorption method is widely accepted in drinking water for its low cost and high efficiency. The research on the new materials and new processes and the improvement of the adsorption properties of the traditional materials are the most studied. Active magnesium oxide is a simple metal oxide, which can be used as a fluorine removal material, but it is difficult to be used in practical engineering because of its long time to achieve equilibrium and the lower price. In order to overcome this limitation of MgO and improve its defluorination performance, sucrose was introduced as modifier in this experiment. After a series of preparation conditions were optimized, the optimum conditions of magnesium oxide / sucrose composite defluorination agent were obtained by Sol-gel method: the mass ratio of magnesium oxide to sucrose was 5: 4, the calcination time and temperature were 150min and 400 鈩，

本文編號(hào)：2120125