污水廠污泥製成活性碳吸附鉛與染料之研究

本研究以迪化污水廠脫水後的二沉池污泥作為研究材料，先將污泥經前處理後，在高溫800度下進行物理活化製成活性碳，再以鹽酸酸洗製成活性碳，然後以硝酸鈰銨為初始劑利用丙烯酸對活性碳進行接枝程序，使COOH官能基能夠嫁接至活性碳表面，增加活性碳對陽離子污染物鉛離子(Pb2+)與甲基綠染料(MG5)之吸附能力。接枝前後的樣品皆利用掃描式電子顯微鏡SEM觀察表面外觀、EDS分析其元素組成、傅立葉轉換紅外光譜儀FTIR分析表面官能基、氮氣吸附孔隙儀量測孔洞性質與比表面積大小。由SEM的結果可以得知活性碳粒徑約在數十μm至100μm左右，EDS分析後可知活性碳主要元素為碳、氧，接枝後多了鈉及鈰。而FTIR顯示接枝程序已成功將COOH官能基嫁接至活性碳表面，增加對陽離子的吸附能力。吸附實驗方面，使用Langmuir方程式計算出最大吸附量，接枝後之樣品將明顯高於接枝前，未接枝樣品對染劑(MG5) 的最大吸附量為8.45 mg/g及對重金屬(Pb2+)的最大吸附量為7.49 mg/g，已接枝樣品由於明顯增加COOH官能基，可利用離子交換增加吸附量，對染料(MG5) 的最大吸附量為65.4 mg/g及對重金屬(Pb2+)的最大吸附量為101mg/g。

關鍵字

活性碳；吸附；鉛離子；甲基綠；污泥；接枝

並列摘要

The objective of this study is to develop the activated carbon from sludge of sewage treatment to adsorb cationic contaminants including lead and dyes from aqueous solution. The obtained sludge formed powder through the pretreatment. The sample was calcined using physical activation process under 800oC and then acid wash by HCl. Finally, the activated carbon were copolymerized carboxylate salt by grafting process with acrylic acid. The samples were characterized using SEM, EDS, FTIR and nitrogen adsorption /desorption isotherms. The SEM shows that the diameter of activated carbon is ranged from 10 to 100 micrometers. For EDS analysis, it was found that the main elements for the activated carbon were C and O. After grafting process, Na and Ce also was regarded as one of main elements. The FTIR demonstrated that the grafting procedure has successfully grafted the COOH functional groups on the activated carbon surface, increasing the adsorption capacities for the cationic contaminants. For adsorption experiments, the maximum adsorption capacity was calculated using the Langmuir equation. The grafting process can effectively increase the adsorption capacity for cationic contaminants. The maximum adsorption capacities of ungrafted activated carbon for dye (MG5) and heavy metal (Pb2+) were 8.45 mg/g and 7.49 mg/g, respectively. Due to the increase in the COOH on the activated carbon, MG5 and Pb2+ can be adsorbed by the ion exchange. The maximum amounts of MG5 and Pb2+ on the grafted activated carbon were 65.4 mg/g and 101 mg/g, respectively.