本文選題：偕胺肟化碳納米管 + 鈾��； 參考：《南華大學》2015年碩士論文

【摘要】：由于工農(nóng)業(yè)的迅速發(fā)展,導致排放入水體中的重金屬含量越來越高,已經(jīng)達到了不可忽視的地步。由于鈾元素具有放射性和化學毒性雙重危害,如何有效的處理廢水中的鈾污染已經(jīng)引起了科研人員的廣泛關(guān)注。對于重金屬的另一種元素鉛,與鈾元素相比,雖然沒有放射毒性,但鉛離子的潛在毒性(如致癌、致畸、致突變)也是不能忽視的,尤其是隨著近年來鉛污染事件的頻繁發(fā)生,使人們意識到對廢水中鉛污染的治理也迫在眉睫。本文以多壁碳納米管為原料,先進行羧基化、酰氯化、酰胺化,然后經(jīng)過氰基化、胺肟化得到偕胺肟化碳納米管(AO-MWNTs)。對所得產(chǎn)物進行紅外光譜、掃描電鏡、透射電鏡等表征。通過靜態(tài)實驗,研究在不同的p H值、振蕩時間、溫度、投加量等條件下研究改性碳納米管對鈾和鉛的吸附性能,并對吸附過程進行動力學和熱力學分析,借助SEM、FTIR等儀器分析手段探討其吸附機理。實驗結(jié)果表明:當p H為5時,改性前碳納米管(raw-MWNTs)和AO-MWNTs對鈾的吸附效果最好,羧基化碳納米管(COOH-MWNTs)和氨基化碳納米管(NH2-MWNTs)對鈾的最佳吸附p H值為6。隨著吸附時間和鈾初始濃度的不斷增大,這四種吸附材料對鈾的吸附容量都逐漸增大,這四種吸附材料對鈾的吸附能力從大到小依次為:AO-MWNTsNH2-MWNTsCOOH-MWNTsraw-MWNTs,而隨著吸附劑投加量的不斷增大,吸附容量不斷降低。在CO32-、SO42-陰離子共存的情況下,對偕胺肟化碳納米管吸附鈾的影響較大,而陽離子Zn2+、Pb2+共存的情況下對該吸附效果的影響較小。動力學擬合結(jié)果顯示:這四種材料對鈾的吸附都符合準二級吸附動力學模型,熱力學模型符合Langmuir模型。AO-MWNTs在鉛初始濃度為10mg/L、溫度為25℃、p H=6、吸附劑投加量為0.025g時,其對鉛離子的吸附容量能達到17.24mg/g。而未改性的碳納米管在同等條件下對鉛的吸附容量只能達到8.3mg/g。AO-MWNTs對鉛的吸附過程在動力學方面符合準二級動力學模型,在熱力學方面Freundlich能更好的描述該過程。
[Abstract]:Due to the rapid development of industry and agriculture, the heavy metal content discharged into the water becomes higher and higher, which can not be ignored. Because uranium has the dual harm of radioactivity and chemical toxicity, how to effectively treat uranium pollution in waste water has attracted extensive attention of researchers. For lead, another element of heavy metals, although it has no radiotoxicity compared with uranium, the potential toxicity of lead ions (such as carcinogenesis, teratogenicity, mutagenicity) cannot be ignored, especially with the frequent occurrence of lead contamination in recent years. To make people aware of the treatment of lead pollution in wastewater is also imminent. In this paper, multiwalled carbon nanotubes (MCNTs) were prepared by carboxylation, acylation, amidation, and then cyanoylation, amidation to obtain AO-MWNTsO. The products were characterized by IR, SEM and TEM. The adsorption properties of modified carbon nanotubes for uranium and lead under different pH values, oscillating time, temperature and dosage were studied by static experiments, and the kinetics and thermodynamics of the adsorption process were analyzed. The adsorption mechanism was discussed by means of SEMX FTIR and other instruments. The experimental results show that when pH is 5, the adsorption of uranium by modified pre-carbon nanotubes (PNTs) and AO-MWNTs is the best. The best adsorption pH value for uranium by COOH-MWNTs and NH2-MWNTs is 6. With the increasing of the adsorption time and the initial concentration of uranium, the adsorption capacity of the four adsorbents for uranium gradually increased. The adsorption capacity of the four adsorbents for uranium was in the order of: AO-MWNTsNH2-MWNTsCOOH-MWNTsraw-MWNTswith the increasing amount of adsorbent. The adsorption capacity is decreasing. The adsorption of uranium by amidoxime carbon nanotubes (CNTs) is greatly affected by the coexistence of CO32-OSO42-anions, while the adsorption of uranium by cationic Zn2 Pb2 has little effect on the adsorption. The kinetic fitting results show that the adsorption of uranium by these four materials is in accordance with the quasi-second-order adsorption kinetic model, and the thermodynamic model accords with the Langmuir model .AO-MWNTs when the initial concentration of lead is 10 mg / L, the temperature is 25 鈩，

本文編號：1794457