奈米技術應用於水處理吸附及薄膜程序中之發展回顧

Abstract

水是人類文明的重要資源。可靠的自來水供應以及適當的市政污水處理不僅對人民的健康與福利至關重要，而且也是社會經濟的重要影響因子。如何取得潔淨及平價之給水是21世紀的全球性課題。 納米技術擁有促進水處理，提高處理效率，以及通過安全使用非常規水源，來增加供水的潛力。本篇綜述回顧了近年納米技術應用於薄膜處理和吸附處理的發展。討論近期學界研究較多的納米材料，簡述性能、處理機制和應用程序，並分析其優點和局限性。本文還探討了與現有的流程相比，新技術付諸應用及商業化需要克服之障礙，及相應之研究方向。 本文追踪納米材料水處理技術的研究前沿，並得出結論：奈米吸附劑中，碳質奈米吸附劑對電鍍、印染以及含重金屬之污水均有良好發展前景，亦可應用於核污染水體處理；金屬奈米吸附劑藉由優化製程可以應用於重金屬污水處理以及核污染水體處理。奈米結構薄膜，尤其是以陣列奈米碳管和石墨烯兩類新材料為基礎的薄膜，在研究中展現出了優異的特性，可能在淡化以及超純水製備領域成為取代現有薄膜的新材料。混合矩陣薄膜適宜客製化商業模式，而奈米技術改進後的正滲透則有望在海水淡化等領域發揮優勢。若後續研究中這些新技術能得以實用化，則可為未來水資源危機的解決增加新助力。

Water is a vital resource for human civilization. Reliable water supply and appropriate municipal wastewater treatment is important not only for the public health but also for sustainable economic growth. Providing clean water to meet human needs is a great challenge of the 21st century. Great potential has been revealed that nanotechnology employed in water treatment could improve treatment efficiency and increase water supply through safe use of unconventional water sources. This review points out development in nano-enabled membranes and adsorbents technology for water and wastewater treatment in recent years. The discussion covers promising nanomaterials, their properties and processing mechanisms, advantages and disadvantages as compared to existing processes, and barriers and research needs for commercialization. By racing the technological advances, opportunities and limitations of nanomaterials, this review conclude that: carbon-based nano-adsorbents can be used to purified wastewater of electroplating and dyeing, as well as to restore radionuclide-polluted water. Metal-based adsorbents are effective in treating wastewater containing heavy-metals and radionuclides. Nano-structured membranes are the most promising materials, especially those built on the unique properties of CNTs & graphene, which could lead to a revolution in desalination and ultrapure water production. Mix matrix membranes are suitable for customized business model. Advancements in nanotechnology improved forward osmosis suggest that FO could have better performances in desalination. If future research overcame the commercialization hurdles, these new technologies would become powerful tools against the coming water crisis.