利用D2EHPA改質活性碳去除水中重金屬鎘之研究

Cadmium removal by D2EHPA-impregnated granular activated carbon

吳惠菁(Hui-Ching Wu)

指導教授 ： 李奇旺

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2008年)

https://doi.org/10.6846/TKU.2008.00982

摘要

本研究利用萃取劑D2EHPA改質粒狀活性碳(GAC)，以提升活性碳吸附金屬的效率。由控制不同實驗參數找出最佳吸附效率的參數值，利用這些參數值進行動力吸附模式、等溫吸附模式模擬與管柱實驗。
批次式吸附實驗結果顯示平衡時間與最佳吸附效率的pH值分別為12小時與pH 7。動力吸附模式模擬結果顯示，改質後的活性碳(DGAC)與GAC在溫度為25℃，pH值為7的條件下，分別吸附濃度為100及200 mg/L鎘金屬溶液，以擬二階反應模式最符合，其線性回歸R2皆在0.995以上。等溫吸附模式的模擬結果顯示， Langmuir等溫吸附模式最符合，求出的DGAC和GAC最大吸附量各別為21.93與11.44 mg/g。在管柱實驗裡，DGAC無法直接使用，因為pH值是影響吸附能力的主要因素，當pH值下降，吸附效率隨即降低，所以DGAC應用在管柱前，需要先以鈉離子替換DGAC的氫離子，避免pH值下降，影響吸附效率。
最後由批次實驗與管柱測試結果，得知利用D2EHPA改質粒狀活性碳(GAC)，確實可有效提升吸附金屬的能力，對鎘金屬的去除效率可提升約2倍。

關鍵字

改質 ； 活性碳 ； D2EHPA ； 吸附 ； 鎘

並列摘要

GAC was impregnate with D2EHPA (di(2-ethylhexyl) phosphoric acid) dissolved in acetone to enhance its metal adsorption capacity for cadmium removal from aqueous solution. Batch adsorption experiments were conducted under different D2EHPA dosages, temperature, equilibrium time, and pH. According to the experiments results, the equilibrium time, optimum D2EHPA dosages, and optimum pH were found to be 12 hr, 10 g, and 7, respectively. Adsorption processes were found to follow pseudo-second order rate equation at two different initial concentrations of 100 and 200 mg/g. Adsorption isotherms correlate well with the Langmuir isotherm model and the maximum sorption capacity of impregnated GAC for cadmium is 21.93 mg/g.

並列關鍵字

impregnated ； granular activated carbon (GAC) ； D2EHPA ； adsorption ； cadmium

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