海水淡化程序RO膜生物性阻塞之特性及減緩

Abstract

目前國內澎湖、金門、馬祖等島嶼型態地區因地表水源缺乏，故目前以海淡廠或鹹井水淡化廠為當地民生用水之主要供給來源，其中淡化程序之水處理方式以RO逆滲透為主，然目前各海淡廠及鹹井水淡化廠皆面臨嚴重的薄膜阻塞問題，並未有進一步之原因探討，故檢視阻塞原因及改善操作方式實為現階段刻不容緩的研究議題。故本研究首先乃針對現有海淡廠之RO膜阻塞原因進行鑑定，提供作為淨水程序操作上的改善參考依據，此外，更進一步於澎湖烏崁海淡廠設立模型廠，針對國外及本研究群之研究經驗提出生物性積垢為海淡廠最嚴重的阻塞型態，進行深入探討，包括生物性積垢之微生物活性探討、季節及RO濃縮倍率對生物性積垢之影響，進而進行奈米銀RO膜改質，探討其對生物性積垢之控制，其中針對微生物之活性主要利用PKH26活菌染劑進行染色觀察與計數，定義微生物隨濾程之增生率，探討其對RO膜操作效能之影響，並於每一試程結束後，進行積垢物之萃取分析及其他儀器分析，以全面瞭解造成RO膜阻塞之成因。

Penghu archipelago, Kinmen, and Matsu islands are arid area, where water supply depends solely on the desalination of seawater and brackish groundwater. The desalination plants face serious fouling problems similar to those in other parts of the world. The operators have being struggling to solve these problems with frequent cleaning and switching to more powerful cleaning reagents through trial and error. Effective membrane cleaning relies on a thorough understanding of the nature of the foulant. In this study, a seawater RO (SWRO) membranes was autopsied and the characteristics of fouling were diagnosed to provide the plants with information to aid the improvement of the systems regarding fouling mitigation. Literatures and preliminary studies have suggested that biofouling is the major cause of fouling in the SWRO system. A pilot study was established in the Wukan SWRO plant. The survival ratio of microbes deposited on the membranes from the inlet was estimated to investigate the effects of seasonal change and concentration ratio of brine on the microbial activity on the membranes. Mitigation of biofouling was explored by modifying RO membranes with silver nanoparticles. The proliferation of microbes was identified by using PKH26 as the survival cell stain. Foulants was extracted and analyzed at the end of tests provided for discussing with biofouling.