本文選題：殼聚糖 + 制備�。� 參考：《武漢理工大學》2013年碩士論文

【摘要】：本課題選取蝦殼為原料制備殼聚糖(CS),探究了氫氧化鈉濃度、殼聚糖與氫氧化鈉溶液質(zhì)量比、pH值、反應(yīng)溫度和時間對CS脫乙酰度的影響以及過氧化氫濃度在其降解過程中對CS分子量的影響；探究了絮凝過程中CS分子量、脫乙酰度、投加量,pH值,攪拌速度和時間分別與有機物、濁度、COD、殘余鋁的去除關(guān)系。由于工業(yè)的高速發(fā)展使得我國大部分河流湖泊中有機污染物的種類和數(shù)量增多,常規(guī)的絮凝處理無法完全去除這些污染物,并且會導(dǎo)致二次污染,而CS在水處理中因天然無毒成為研究熱點,通過與無機絮凝劑復(fù)合使用,考察了其在給水處理中的絮凝效果,其效果較傳統(tǒng)絮凝劑更加環(huán)保、高效且價格低廉。 以潛江蝦殼為原料,用3.75%的鹽酸去除鈣質(zhì),4.5%氫氧化鈉脫蛋白,即可制備甲殼素。通過甲殼素制備高脫乙酰度殼聚糖的反應(yīng)條件為：48%的氫氧化鈉溶液,料堿比為1：9,反應(yīng)溫度90℃,反應(yīng)時間2.5h,實驗表明殼聚糖脫乙酰度可以達到85.3%,殼聚糖分子量為6.23×105。通過紅外光譜和X-射線衍射等對殼聚糖樣品進行表征并初步分析了其結(jié)構(gòu)和降解機理。 考察了殼聚糖對水中有機物的吸附效能,結(jié)果表明：當殼聚糖脫乙酰度在78～85%、分子量為5.83×104左右,pH值為6.0～6.5時,殼聚糖對COD的去除率較高。根據(jù)無機、有機、無機-有機復(fù)合原理,對PAC、CF-PAC、CS以及PAC/CS、 CF-PAC/CS對模擬地表水進行絮凝實驗,結(jié)果表明：CF-PAC (20.0ppm)在CS(0.10ppm)助凝作用下,快攪速度300r/min(60s),'曼攪速度60r/min(10min),出水濁度可以達到0.4NTU以下,鋁離子的含量僅為0.041mg/L,較傳統(tǒng)的PAC低76.02%,較PAC/PAM低70.07%,使得飲用水更加的健康,且噸處理費用較傳統(tǒng)絮凝劑PAC略低。 對復(fù)合絮凝劑的機理做了簡要的探析。復(fù)合絮凝劑中CF-PAC組分在水中先水解后聚合,其中鐵離子先快速的水解,隨后鋁離子水解,水解后鐵離子和鋁離子形成的多核羥基呈現(xiàn)正電性,可以迅速和水中負電膠體微粒吸附結(jié)合。CS水解后分子鏈上的氨基和羥基質(zhì)子化而帶上正電荷,進一步加大了絮凝的電中和作用,同時其長分子鏈迅速的連接相鄰微粒形成架橋作用。CF-PAC與CS的復(fù)合絮凝使得電中和作用、架橋、網(wǎng)捕卷掃協(xié)同作用,縮短了絮凝沉降時間,提高了絮凝效果。
[Abstract]:In this paper, chitosan (CS) was prepared from shrimp shell. The concentration of sodium hydroxide and the mass ratio of chitosan to sodium hydroxide solution were studied. The effect of reaction temperature and time on CS deacetylation degree and the effect of hydrogen peroxide concentration on CS molecular weight in the process of degradation were studied. Stirring speed and time are related to the removal of organic matter, turbidity, COD and residual aluminum, respectively. Due to the rapid development of industry, the species and quantity of organic pollutants in most rivers and lakes in our country increase, and the conventional flocculation treatment can not completely remove these pollutants, and will lead to secondary pollution. CS has become a research hotspot in water treatment because of its natural non-toxicity. The flocculation effect of CS in water treatment was investigated by using inorganic flocculant. Compared with traditional flocculant, CS was more environmentally friendly, efficient and cheap. Chitin was prepared from Qianjiang shrimp shell with 3.75% hydrochloric acid removing 4.5% sodium hydroxide deproteinization. The reaction conditions of chitosan with high degree of deacetylation from chitin were as follows: 1: 48% sodium hydroxide solution, 1: 9 ratio of material to alkali, 90 鈩，

本文編號：2065072