微波加速零價鐵還原六價鉻之研究

A Study of Microwave Accelerated Reduction of Hexavalent Chromium by Zero-Valent Iron

葉致榮(Chih-Jung Yeh)

指導教授 ： 許道平

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2010年)

https://doi.org/10.6846/TKU.2010.00891

摘要

本研究係改裝家用微波爐以建立零價鐵還原六價鉻之快速處理裝置，經酸洗過後之鐵粉及自行配製之六價鉻溶液置於消化管中，以微波搭配振盪處理水樣，時間上不但能從所需數小時以上之傳統處理方式縮短至數十秒鐘，且裝置拆裝簡易，可縮短整體實驗所花費之總時間。
本研究逐一進行實驗測試及儀器改良，首先確認微波系統可縮短處理時間，再建立微波密閉系統以及其安全性測試，然後搭配自行設計之鐵氟龍振盪處理器，建立一套快速簡易處理裝置，最後再以田口氏實驗設計，尋找微波最佳化條件之參數。實驗結果顯示最佳化條件為：六價鉻溶液pH = 2、鐵粉重0.1611 g（酸洗前重、六價鉻與零價鐵莫爾數比1：500）、微波功率575 W、微波時間20秒。
利用最佳化實驗條件來進行零價鐵還原六價鉻實驗，其反應後六價鉻去除率之精密度RSD在5 %以內，顯示處理系統有良好之穩定性及再現性。

關鍵字

零價鐵 ； 六價鉻 ； 微波消化

並列摘要

A simple system for hexavalent chromium removal by iron powder in the wastewater treatment using microwave to replace the conventional treatment method is proposed. The goal of this study is to accelerate the rate of the reaction which hexavalent chromium reacts with the acid-washed iron powder in a home-made microwave oven combined with oscillator.
This method consists of a small test tube (10 mL) where the iron powder and chromium solution were added and oscillated while microwave heating. The detection of chromium and trivalent chromium were carried out by atomic absorption spectrophotometer and colorimeter, respectively.
In order to estimate the optimum levels and determine the relative magnitude of the effect of various factors, a number of experiments were performed. The microwave heating parameters for optimization were as follows: microwave power 575 W, reaction time 20 seconds, hexavalent chromium concentration 100 ppm and mole ratio (Fe/Cr) 500. The results showed that the hexavalent chromium removal by iron powder was 95 % (n = 10), relative standard deviation 5 %.

並列關鍵字

zero-valent iron ； hexavalent chromium ； microwave digestion

參考文獻

35.劉景文，“零價鐵去除水中六價鉻之研究”，國立台灣大學環境工程學研究所碩士論文，民國九十四年。

42.紀柏亨、楊末雄、孫毓璋，“微波消化之方法應用”，中國化學會化學期刊，第五十六卷，第四期，pp.269-284，民國八十七年。

3.Shan, J.H., Fan, L., Huo, S.Y., Zhu, J.J., Liu, H.M., and Shen, S.G., “Mechanism and Kinetics of the 2,2′-Bipyridyl Catalysis of the Chromium(VI) Oxidation of Malic Acid”, Journal of the Iranian Chemical Society, Vol. 4, No. 4, pp. 476-480, 2007.

4.Fendorf, S. E., “Surface reactions of chromium in soils and waters” , Scott E. Fendorf, Geoderma, Vol. 67, pp. 55-71, 1995.

7.Bagchi, D., Stohs, S. J., Downs, B. W., Bagchi, M., and Preuss, H. G. “Cytotoxicity and oxidative mechanisms of different forms of chromium”, Toxicology, Vol. 180, pp. 5-22, 2002.