氯化鋅製備麻竹活性碳對水溶液鎘離子之吸附效能

Adsorption Efficiency of Ma bamboo Activated Carbon Prepared by Zinc Chloride for Absorbing Cadmium Ion from Aqueous Solution

劉素玲(Su-Ling Liu) ； 盧崑宗(Kun-Tsung Lu)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 33卷2期 (2019/06) Pp. 107-117

https://doi.org/10.6542/EFNTU.201906_33(2).0004

摘要

本研究探討以氯化鋅製備麻竹活性碳做為吸附劑，在30、60、90及120 min等4種不同的持溫時間下，對不同濃度水溶液中鎘離子之吸附效能，並分析其等溫吸附模式。界面電位分析結果顯示4種不同持溫時間麻竹活性碳在pH 3〜7之水溶液中之表面均帶負電荷，此結果有利於鎘離子之吸附。4種麻竹活性碳表面結合之酸性官能基含量較低，其中羧基含量0.04〜0.08 m mol/g、內酯基為0.09〜0.20 m mol/g、酚基為0.09〜0.27 m mol/g等，而鹼基含量則較高（介於0.46〜0.54 m mol/g之間）。不同初始濃度吸附水溶液鎘離子，以持溫30 min製備者具最佳吸附效能。麻竹活性碳吸附水溶液鎘離子之吸附機制屬於離子交換與靜電作用。以Langmuir與Freundlich等溫吸附模式分析4種活性碳對鎘離子之吸附，由此二種吸附模式的常數得知，以持溫時間30、60、120 min製備之活性碳皆有利於吸附鎘離子，若依決定係數R^2值判斷，則多層吸附之Freundlich等溫吸附模式較符合此三種活性碳之吸附行為。

關鍵字

麻竹活性碳 ； 氯化鋅 ； 鎘離子 ； 吸附效能 ； 等溫吸附模式

並列摘要

In this study, we investigated the adsorption efficiency of Ma bamboo (Dendrocalamus latiflorus) activated carbons prepared by zinc chloride with different holding times of 30, 60, 90 and 120 minutes for absorbing cadmium ion (Cd^(2+)) from aqueous solution, and examined their adsorption isotherm models. According to the Zeta potential analysis, the surface of activated carbons with four kinds of holding times all carried negative charge in aqueous solutions of pH 3-7, indicating greater absorption of cadmium ion. The surface of four kinds of activated carbons had a lower content of acidic functional groups, such as carboxyl group of 0.04~0.08 mmol/g, lactone group of 0.09~0.20 mmol/g and phenol group of 0.09~0.27 mmol/g; however, they possessed a higher base groups of 0.46~0.54 mmol/g. The activated carbon with holding time of 30 min had the best adsorption efficiency for absorbing cadmium ion from aqueous solutions with different initial concentrations. The adsorption mechanism of Ma bamboo activated carbon is classified as ion exchange and electrostatic interaction. According to the analysis results from parameter data of both Langmuir and Freundlich models, the activated carbons with holding time of 30, 60, 120 min all showed good efficiency in adsorbing cadmium ion from aqueous solution. With further consideration of the coefficient of determination (R^2), the Freundlich adsorption isotherm model showed better fit on the multilayer adsorption to the adsorption behavior of the three kinds of activated carbons.

並列關鍵字

Ma bamboo activated carbon ； Zinc chloride ； Adsorption efficiency ； Cadmium ion ； Adsorption isotherm model