電容去離子技術應用於硬水軟化

Capacitive Deionization for Water Softening Application

王靖逸(Ching Yi Wang)

指導教授 ： 彭晴玉

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2018年)

https://doi.org/10.6846/TKU.2018.00179

摘要

全球發展造成水資源匱乏與工業用水激增，因此增加純淨水與硬水處理受到各地之關注。
電容去離子技術(Capacitive deionization, CDI)為一新穎的海水淡化技術，其原理為利用電吸附機制去除水中離子，具有低耗能、低成本、操作簡易與無二次汙染等優勢，應用層面廣泛，除可應用於脫鹽外，亦可應用於硬水軟化處理。
影響CDI技術的重要因素之一為電極材料之選擇，本研究其中一個目的為探討對環境友善之三種還原劑製備石墨烯為基本電極，進行鹽水與硬度離子之去除，其中以HMTA製備之石墨烯擁有最高之比電容量(82.71 F/g)，對NaCl去除率達4.4 %，並對硬度離子Ca2+、Mg2+可分別達到2.74與0.56 mg/g之電吸附量。石墨烯對Ca2+、Mg2+、Na+電吸附之離子選擇性為Ca2+ > Mg2+ > Na+。
本研究另一目的為製備奈米Mn/rGO複合材料，藉由添加奈米錳提升原始石墨烯之親水性與比電容(111.42 F/g)，並組成非對稱電容去離子系統去除硬度離子處理，對Ca2+、Mg2+、Na+ 分別達2.83、1.05與0.61 mg/g之吸附量，與對稱CDI系統相比，更有效提升其電吸附量。

關鍵字

對稱/非對稱電容去離子 ； 硬水軟化 ； 錳/石墨烯複合材料

並列摘要

Global development has led to water scarcity and increasing industrial water usage, so increasing pure water and treatment of hard water has received lots of attention worldwide.
Capacitive deionization (CDI) technology is a novel desalination technology. The principle of CDI is to remove ions in water by electrosorption mechanism, it has the advantages of low energy consumption, low cost, easy operation and no secondary pollution generated. CDI has a wide range of applications, in addition to desalination, it can also be applied to hard water softening treatment. One of the important factors affecting CDI technology is the selection of electrode materials.
One of the objectives of this study was to investigate the differences of three environmentally friendly reducing agents used to prepare the graphene for removing NaCl and hardness ions. Among them, graphene prepared by HMTA has the highest specific capacitance (82.71 F/g), the NaCl removal efficiency is 4.4%, and the electrosorption capacity of hardness ions Ca2+ and Mg2+ can be achieved to 2.74 and 0.56 mg/g, respectively. The ion selectivity of graphene electrosorption is Ca2+ > Mg2+ > Na+.
Another purpose of this study is to prepare nano-Mn/rGO composites, which can improve the hydrophilic and specific capacitance (111.42 F/g) of the original graphene by adding nano-manganese. An asymmetric capacitive deionization system to remove the hardness ion was also compared in this study.
The electrosorption capacity of Ca2+, Mg2+, and Na+ was 2.83, 1.05, and 0.61 mg/g, respectively, in the symmetric CDI system. Compared with the symmetric CDI system, asymmetric capacitive deionization is more effective in increasing the electrosorption capacity.

並列關鍵字

symmetrical/asymmetric capacitive deionization ； hard water softening ； manganese/graphene composites

參考文獻

References

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