本文選題：羧甲基纖維素 + 聚丙烯酰胺��； 參考：《長安大學(xué)》2015年碩士論文

【摘要】：我國水資源問題日趨嚴(yán)重,水資源匱乏與污染現(xiàn)狀正不斷加劇,近年來,工業(yè)污水成為水資源污染的主要來源,其成分復(fù)雜,含有多種難降解有機(jī)污染物,給人們的生活帶來嚴(yán)重威脅。尤其是污染廢水的化學(xué)需氧量,處理難度大,治理費(fèi)用高。因此尋求低成本、高效率的水污染處理方法是我們迫切解決的問題之一,也是可持續(xù)發(fā)展的必然要求。聚丙烯酰胺作為一種常用水處理劑,是一種水溶性線性高分子有機(jī)物,在實(shí)際應(yīng)用中易吸潮結(jié)塊,且成本較高,因此設(shè)想將聚丙烯酰胺引入到羧甲基纖維素大分子結(jié)構(gòu)中,制備一種高效率、低成本的兼具兩者優(yōu)良性質(zhì)的水處理劑。本課題將聚丙烯酰胺接枝到羧甲基纖維素分子骨架上,在一定條件下,經(jīng)過硫酸鉀-亞硫酸氫鈉雙引發(fā)劑引發(fā),通過自由基聚合過程形成有機(jī)高分子聚合物。以接枝率為主要參考指標(biāo),研究了物料比、引發(fā)劑用量、起始溫度、反應(yīng)時間和pH等因素的影響。在此基礎(chǔ)上還選取影響接枝率較大的四個因素進(jìn)行正交實(shí)驗(yàn),并以丙酮為溶劑對粗產(chǎn)品進(jìn)行回流提純,對接枝絮凝物進(jìn)行了紅外和核磁分析。最終確定了合成羧甲基纖維素-聚丙烯酰胺接枝絮凝劑的最佳條件:CMC為1g時,CMC:AM=1:8,初始pH=9,K2S2O8-NaHSO3雙引發(fā)劑用量為1mL,接枝溫度為40℃,反應(yīng)時間3.5h,此時接枝率達(dá)到60.12%。影響接枝因素的強(qiáng)弱順序?yàn)?pH㧐引發(fā)劑用量㧐接枝溫度㧐反應(yīng)時間。反應(yīng)得到的羧甲基纖維素-聚丙烯酰胺接枝聚合產(chǎn)物為白色粉末,在水中形成疏松的海綿結(jié)構(gòu),性質(zhì)較穩(wěn)定,兼具了羧甲基纖維素和聚丙烯酰胺的性質(zhì)。配置實(shí)驗(yàn)室模擬廢水,采用重鉻酸鉀法測定其初始的CODcr=519.792mg/L。將制備的CMC-PAM絮凝劑用于處理廢水,以CODcr為參考指標(biāo),持續(xù)曝氣條件下考察了CMC-PAM用量、絮凝時間、pH的影響,并設(shè)計正交實(shí)驗(yàn)確定其影響大小。得到的最佳處理?xiàng)l件為:CMC-PAM用量150mg/L,pH=9,絮凝1.5h,COD的最大去除率為49.27%。各因素的影響順序?yàn)?pH㧐投加量㧐絮凝時間。CMC-PAM降解廢水COD的機(jī)理主要包括:壓縮雙電層、吸附電中和、吸附架橋、沉淀物卷掃等。
[Abstract]:In recent years, industrial sewage has become the main source of water resources pollution, its composition is complex, and it contains a variety of refractory organic pollutants. It poses a serious threat to people's lives. In particular, the chemical oxygen demand (COD) of polluted wastewater is difficult to treat and the cost of treatment is high. Therefore, to seek low cost and high efficiency water pollution treatment method is one of the urgent problems we solve, and is also the inevitable requirement of sustainable development. As a common water treatment agent, polyacrylamide is a kind of water-soluble linear polymer organic matter, which is easy to absorb moisture and agglomerate in practice, and its cost is high. Therefore, it is envisaged to introduce polyacrylamide into the macromolecular structure of carboxymethyl cellulose. A water treatment agent with high efficiency and low cost was prepared. In this paper, polyacrylamide was grafted onto the molecular skeleton of carboxymethyl cellulose. Under certain conditions, organic polymer was formed by radical polymerization through potassium sulfate and sodium bisulfite double initiator. The effects of material ratio, initiator dosage, initial temperature, reaction time and pH were studied. On this basis, four factors affecting the grafting rate were selected for orthogonal experiments. The crude products were purified by reflux with acetone as solvent, and the grafted flocculants were analyzed by IR and NMR. Finally, the optimum conditions for the synthesis of carboxymethyl cellulose-polyacrylamide graft flocculant were determined. The optimum conditions were as follows: 1 g CMC: AMN: 1 8, initial pH 9 K2S2O8-NaHSO3 double initiator dosage 1 mL, grafting temperature 40 鈩，

本文編號：2072652