以戊二醛交聯幾丁聚醣圓珠吸附水溶液中酸性染料AO12之研究

幾丁聚醣是一種良好的吸附劑，為了降低幾丁聚醣在水中的溶解度並具有廣泛的pH適用範圍，本研究以0.25%的戊二醛溶液去交聯幾丁聚醣圓珠，做為吸附劑，並用於吸附水溶液中之酸性染料，AO12。為了以UV-Visible測定酸性染料濃度，我們測得染料的最大吸收波長為482nm，吸收係數為23.13(上標 *)10^(-4)cm^(-1)mol^(-1)L，相關係數R^2值為0.9998。本研究主要透過動力學進行分析研究，來探討pH值、溫度、濃度等因素對吸附速率及等溫吸附平衡等效應的影響。由吸附動力學的分析，了解吸附過程中影響吸附速率的因素，進而找出以交聯幾丁聚醣圓珠吸附酸性染料的較佳條件。研究結果發現以幾丁聚醣交聯小球來吸附本實驗所用的陰離子染料時，其較佳吸附的條件為pH=3，且反應時間200分鐘即可去除90%的酸性染料。提高溫度雖可增加吸附的速率，但並不顯著，且會使飽和吸附量降低，所以以室溫當作反應溫度即可。

關鍵字

幾丁聚醣；戊二醛；酸性染料；吸附；動力學

並列摘要

Chitosan is a good absorbent. In order to reduce chitosan's solubility in water and have a wide range of pH for the experiment, this study used 0.25% glutaraldehyde to prepare chitosan ball for absorbing acidic dye, AO12, in water solutions. In order to determine concentration of acidic dye. we determined the maximum absorption wavelength at 482nm, absorption coefficient of 23.13(superscript *)10^(-4)cm^(-1)mol^(-1)L,. and relative coefficient R^2 of 0.9998.In this paper, we studied the kinetics of pH, temperature, and concentration of acidic dye on the absorption rate and the absorption isotherm of the absorption. We analyzed the results of absorption kinetics and discussed the factors affecting the absorption and then find optimum conditions for absorption of acidic dyes. The better condition for chitosan ball to absorb the acidic dye is pH=3. In this pH, the reaction time of 200 minutes is enough to reach 90% absorption. Although increasing in temperature can increase the rate of absorption, it is not significantly remarkable. Instead, it reduces the saturated adsorption capacity. Therefore, the better reaction temperature is the room temperature.