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  本文選題：聚乙烯醇　切入點：粉煤灰　出處：《蘭州大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：人類的生產(chǎn)及生活活動產(chǎn)生大量含有重金屬的廢水,但是由于某些原因這些廢水未經(jīng)處理或處理未達(dá)標(biāo)就排向自然環(huán)境,導(dǎo)致水體、土壤等受到不同程度的污染。由此引發(fā)的水污染問題已嚴(yán)重危害到經(jīng)濟(jì)的可持續(xù)發(fā)展和公眾身體健康,因而有效的水污染處理技術(shù)的開發(fā)和研究受到了國內(nèi)外學(xué)者的廣泛關(guān)注。吸附法由于吸附材料來源廣泛、價格低廉、操作過程不需要復(fù)雜裝置及添加額外化學(xué)物質(zhì)等優(yōu)點,被越來越多地應(yīng)用在重金屬水污染處理領(lǐng)域。本論文設(shè)計并合成了一系列吸附量大、吸附速率快、去除效率高、對某種金屬離子具有選擇識別性、重復(fù)利用率高且.價格低廉、制備簡單的新型雜化吸附材料。并運(yùn)用掃描電鏡(SEM)、X-射線衍射(XRD)、傅立葉紅外光譜(FT-IR)等技術(shù)對新型吸附劑形貌、晶形、表面功能團(tuán)等進(jìn)行了表征�？疾炝顺跏紳舛取⑷芤簆H值、共存離子等因素對雜化材料去除污水中重金屬離子性能的影響。同時,運(yùn)用各種吸附等溫線模型、動力學(xué)模型對吸附平衡數(shù)據(jù)進(jìn)行模擬,初步探討了吸附過程的機(jī)理,速度控制步驟等。本學(xué)位論文的主要研究內(nèi)容如下：1.聚乙烯醇(PVA)包囊Mn02納米棒的制備及其對水中Hg(Ⅱ)的吸附研究PVA具有低價,生物相容性好,機(jī)械強(qiáng)度大等優(yōu)點,且由于具有大量的羥基,故可用于對重金屬離子的錨定和鍵合。本章采用水熱法制備了結(jié)構(gòu)較為均一的MnO2納米棒。然后以硼酸-CaCl2為成型液制備了PVA/MnO2內(nèi)米棒雜化小球,研究了影響PVA/MnO2納米棒雜化小球吸附Hg2+的主要因素。結(jié)果表明：PVA/MnO2納米棒雜化小球具有大孔三維網(wǎng)狀結(jié)構(gòu),這種大孔網(wǎng)狀結(jié)構(gòu)更有利于金屬離子在其內(nèi)部的擴(kuò)散和吸附。在吸附過程中,PVA和MnO2納米棒呈現(xiàn)出種協(xié)同增強(qiáng)效應(yīng),吸附效率明顯高于單一PVA小球。動力學(xué)試驗顯示,PVA/MnO2納米棒雜化小球?qū)θ芤褐械腍g2+具有較快的吸附速率。同時PVA/MnO2納米棒雜化小球具有明顯的選擇性,可從含多種金屬離子的溶液中選擇性的去除Hg2+PVA中加入Mn02納米棒使新型吸附劑的pH適用范圍更寬廣,在pH值為3-7內(nèi)都具有較好的吸附性能。另外PVA/MnO2小球結(jié)構(gòu)也使得分離過程變得更為簡單和有效,更適用于工業(yè)生產(chǎn)。在此基礎(chǔ)上,采用Langmuir 和 Freundlic h等溫線；準(zhǔn)一級反應(yīng)和準(zhǔn)二級反應(yīng)方程分析了PVA/MnO2納米棒雜化小球的吸附過程。2.納米MnO2修飾粉煤灰的制備及其去除Pb(Ⅱ)和Hg(Ⅱ)的研究粉煤灰是煤燃燒的主要副產(chǎn)物,其中有大量的鋁、硅等金屬氧化物,可以與重金屬離子產(chǎn)生化學(xué)鍵合作用。粉煤灰具有多孔結(jié)構(gòu),比表面積大,有望成為廉價高效的吸附劑材料。本文將過硫酸銨和硫酸錳溶解后加入粉煤灰,一鍋法制備MnO2-粉煤灰雜化材料(FA@nM)。采用一鍋法具有收率較高,操作簡單等優(yōu)點。詳細(xì)研究了影響FA@nM雜化材料對Hg2+和Pb2+吸附的因素。通過多種表征分析了所制備FA@nM雜化材料的表觀形貌、存在的官能團(tuán)、形成的晶形結(jié)構(gòu)、比表面積等。結(jié)果表明,MnO2在FA表面的負(fù)載較為均一,表面結(jié)構(gòu)規(guī)整；FA@nM雜化材料的最大比表面積可達(dá)677 m2/g,負(fù)載后的FA極大的增加了對Hg2+和Pb2+的吸附能力,分別為41和53.2 mg/g。FA@nM雜化材料可以在較寬的pH范圍內(nèi)有效去除Hg2+和Pb2+離子。Langmuir等溫線模型對FA@nM雜化材料吸附Hg2+和Pb2+具有較好的擬合性,表明Hg2+和Pb2+ 在FA@nM表面形成了單分子層吸附。動力學(xué)試驗顯示FA@nM雜化材料對Pb2+的吸附速率明顯快于Hg2+,表面吸附和粒子內(nèi)擴(kuò)散參與到吸附過程當(dāng)中。因此,FA@nM雜化材料作為一種新型復(fù)合材料有望應(yīng)用于工業(yè)污水中重金屬離子的去除。3.生物大分子單寧酸(TA)修飾粉煤灰的制備及其對Pb(Ⅱ)的吸附性能研究單寧酸(TA)具有大量的酚羥基,易溶于水,與重金屬離子錨定和鍵合形成不溶性復(fù)合物。本章主要將粉煤灰、單寧酸、鋇鹽和磷酸鹽反應(yīng)制得FA/TA/BaP雜化型材料,在采用SEM對材料形貌進(jìn)行表征,XRD、FT-IR的分析結(jié)果表明粉煤灰、單寧酸及鋇鹽和磷酸鹽發(fā)生了復(fù)合交聯(lián)反應(yīng),本文以Pb2+為目標(biāo)吸附物。試驗表明：FA/TA/BaP雜化材料對Pb2+的最大吸附容量為216.1 mg/g,遠(yuǎn)遠(yuǎn)大于單一粉煤灰及單寧酸的吸附量。pH研究顯示,FA/TA/BaP雜化材料在較寬pH值范圍內(nèi)都具有較好的吸附行為。研究顯示,FA/TA/BaP雜化材料對Pb2+的吸附符合Freundlich等溫線模型和準(zhǔn)二級動力學(xué)模型,FA/TA/BaP雜化材料對Pb2+的吸附和解吸循環(huán)試驗進(jìn)一步證實了材料具有優(yōu)異的可重復(fù)使用性和穩(wěn)定性。由此可見,A/TA/BaP雜化材料作為一種新型有效的雜化材料可望應(yīng)用于廢水中Pb2+離子的去除及富集。
[Abstract]:The waste water containing heavy metals production and life activities of human being, but for some reason the wastewater untreated or treated with substandard discharge to the natural environment, resulting in water, soil and other polluted. The water pollution problem caused by this has serious harm to the sustainable development of the economy and the health of the public, thus the research and development of water pollution and effective treatment technology has received extensive attention of scholars at home and abroad. Due to the adsorption of wide material source, low price of adsorption process does not require complicated device and add additional chemicals and other advantages, is increasingly used in the field of heavy metal pollution processing. This paper presents the design and synthesis of a series of the adsorption capacity, adsorption speed, high removal efficiency, with selective recognition of certain metal ions, high recycling rate and low price, simple preparation A new hybrid adsorbent. By using scanning electron microscopy (SEM), X- ray diffraction (XRD), infrared spectroscopy (FT-IR) crystal Fu Liye technology of the new adsorbent, morphology, surface functional groups were investigated. The effects of initial concentration, pH value of solution, influence of coexisting ions on the heavy metal removal performance of sewage in the hybrid materials. At the same time, the use of various adsorption isotherm model, dynamic model simulation of adsorption equilibrium data, discussed the mechanism of the process, the rate controlling step. The main research contents of this thesis are as follows: 1. polyvinyl alcohol (PVA) preparation of encapsulated Mn02 nanorods and Hg on the adsorption of water (II) study on PVA with low price, good biocompatibility, mechanical strength and other advantages, and has a large number of hydroxyl groups, so that it can be used for heavy metal ions on anchoring and bonding. This chapter was prepared by hydrothermal method with structure For the uniform MnO2 nanorods. Then there is PVA/MnO2 -CaCl2 with boric acid to prepare hybrid rod ball forming fluid system, studied the main factors affecting the adsorption of Hg2+ PVA/MnO2 nanorods hybrid ball. The results show that the PVA/MnO2 nanorods hybrid beads with large pore 3D mesh structure, more conducive to the macroreticular structure diffusion and adsorption of metal ions in the interior. In the process of adsorption, PVA and MnO2 nanorods showing a synergistic effect, the adsorption efficiency was significantly higher than that of single PVA ball. The dynamic test showed that, PVA/MnO2 nanorods hybrid beads with higher adsorption rate of Hg2+ in the solution. At the same time PVA/MnO2 nanorods hybrid ball has obvious selectivity, adding Mn02 nanorods Hg2+PVA selectively removal from solution containing a variety of metal ions in the new adsorbent pH scope is wider, the pH value is 3-7 in is Good adsorption properties. In addition PVA/MnO2 ball structure also makes the separation process simpler and more effective, more suitable for industrial production. On this basis, using Langmuir and Freundlic h isotherm; first-order reaction and quasi two order reaction equation analysis of the preparation of PVA/MnO2 nanorods hybrid small ball adsorption process of.2. modified nano MnO2 powder ash and the removal of Pb (II) and Hg (II) of fly ash is the main by-product of coal combustion, which has a large number of aluminum, silicon and other metal oxides, can produce chemical bonds with metal ions. Effect of fly ash has porous structure, large surface area, is expected to become a cheap and efficient adsorbent material. This paper will have. Ammonium sulfate and manganese sulfate solution after adding fly ash, fly ash and preparation of MnO2- hybrid materials (FA@nM). One pot method has higher yield by one pot method, simple operation and so on. A detailed study of the influence of F A@nM hybrid materials of Hg2+ and Pb2+ adsorption. Through a variety of characterization of the synthesized FA@nM hybrid material surface morphology, the presence of functional groups, crystal structure formation, the specific surface area. The results show that MnO2 is in the load on the surface of FA uniform and orderly surface structure; FA @nM hybrid material maximum ratio the surface area of up to 677 m2/g, load FA greatly increased the adsorption capacity of Hg2+ and Pb2+, respectively, 41 and 53.2 mg/g.FA@nM hybrid materials can be in a wide range of pH can effectively remove Hg2+ and Pb2+ ion.Langmuir isotherm model has better fitting of FA@nM hybrid materials for adsorption of Hg2+ and Pb2+, and that Hg2+ Pb2+ formed a single molecular layer adsorption on the surface of FA@nM. The dynamic test showed that the adsorption rate of FA@nM hybrid material of Pb2+ was faster than that of Hg2+. The adsorption and diffusion in the particle surface involved in the adsorption process. Therefore, FA@n M hybrid materials as a kind of new composite material is expected to be applied to the heavy metal ions in industrial wastewater.3. removal of biological macromolecules of tannic acid (TA) modified fly ash and preparation of Pb (II) study on the adsorption of tannic acid (TA) has a large number of phenolic hydroxyl groups, soluble in water and heavy metal ions and anchor the bond formation of insoluble complexes. This chapter will fly ash, tannic acid, barium salt and phosphate was prepared by the reaction of FA/TA/BaP hybrid materials, the materials were characterized by SEM, the morphology of XRD, the results of FT-IR analysis showed that fly ash, the composite crosslinking reaction of tannic acid and barium salt and phosphate, based on Pb2+ as the goal of adsorption. The results showed that the maximum adsorption capacity of FA/TA/BaP hybrid material of Pb2+ is 216.1 mg/g, study on the adsorption capacity of.PH is much larger than a single fly ash and tannic acid showed that FA/TA/BaP hybrid materials in a wide range of pH value Have a good adsorption behavior. The study showed that the adsorption of Pb2+ FA/TA/BaP hybrid material with the Freundlich isotherm model and pseudo two order kinetics model, adsorption and desorption cycle test of FA/TA/BaP hybrid material of Pb2+ further confirmed that the material has excellent reuse and stability. Thus, A/TA/BaP hybrid materials as a kind of new and efficient the hybrid materials could be applied to Pb2+ ion removal and enrichment.

【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X703;TB383.1

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本文編號：1564801