Preparation and Characteristics of Fouling Resistant Nanofiltration Membranes

내오염성 나노여과막의 제조 및 특성

  • Kim, No-Won (Department of Environment Engineering, Dong-Eui University)
  • 김노원 (동의대학교 공과대학 환경공학과)
  • Published : 2007.03.30

Abstract

The primary objective of this study is to increase the extent of water flux and fouling resistance of nano-filtration or reverse osmosis membranes. This study was performed to investigate the effect of surface characteristics of silane coated membranes on modified fouling index. Commercial polyamide composite RO membrane (RE1812-LP) and NF membrane (ESNA4040-LF) were treated with silane coupling agents in ethanol at five different concentrations. The silane coupling reagent, aminopropylmethoxydiethoxysilane, contains one aminoalkyl and three alkoxy groups. The hydrophilic effect of aminoalkyl group of APMDES on the permeability and fouling resistance of the modified membrane was examined. The surfaces of the modified membranes were characterized by FE-SEM, contact angle analyzer, and zeta potentiometer in order to confirm successful sol-gel methods. The modified NF membranes showed significantly enhanced water flux and fouling resistance without a decrease in salt rejection in divalent ionic feed solution.

본 연구에서는 나노여과막과 역삼투막의 표면 개질을 통하여 유량의 향상 및 내오염성을 향상시키는 제조 방법을 개발하였다. 실란 화합물이 코팅된 복합막의 표면 성질이 막 오염 지수 MFI 값에 미치는 영향을 살펴보았다. 상용화된 역삼투막(RE1812-LP)과 나노여과막(ESNA 4040-LF) 복합막을 기저막으로 사용하여 실란 커플링제의 농도를 달리하여 개질 복합막을 제조하였다. 실란 커플링제 aminopropylmethoxydiethoxysilane은 아민 관능기와 3개의 알콕시 관능기를 가지며 아민 관능기가 가지는 친수성 특성이 개질막의 투과 수량 및 내오염성에 미치는 영향을 조사하였다. 개질막의 실란층의 안정적인 형성을 확인하기 위하여 FE-SEM, 접촉각 측정 및 제타 전위값 등의 표면 특성 변화를 살펴보았다. 특히 개질된 나노여과막의 2가 이온 수용액을 공급수로 할 경우 염제거율에 대한 영향 없이 내오염성이 현저히 증가함을 확인하였다.

Keywords

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