The purpose of this study is to find the operational characteristics of nitrifier-dominated membrane bioreactor (MBR), which has been extensively studied for organic removal, especially in terms of nitrite (NO2-N) build-up and membrane fouling. Membrane fouling is one of the important factor which determines the economics of MBR system. The characteristics of membrane fouling was monitored in terms of the fouling indices such as sludge volume index (SVI), the concentration of total organic carbon (TOC) and extracellular polymeric substances (EPS) in a membrane permeate or sludge extract, the absorbance of supernatant at 260 nm. Most of index values except for protein concentration in EPS had a close relation with the increase of suction pressure and SVI value. Nitrifying MBR was superior to the conventional organic-oxidizing MBR in terms of membrane fouling since the fouling index value of nitrifying MBR was lower than that of BOD-oxidizing MBR.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. MBR 구성
  2.2. MBR 운전조건
  2.3. 폐수의 조성
  2.4. 분석방법
 3. 결과 및 고찰
  3.1. 질산화 MBR의 슬러지 침전성과 질산화 효율
  3.2. 질산화 MBR의 아질산성 질소 축적
  3.3. 질산화 MBR의 막오염 특성
 4. 결 론
 참 고 문 헌

• 임경조(울산대학교 생명화학공학부) | Kyoung Jo Lim (School of Chemical Engineering and Bioengineering, University of Ulsan)
• 홍순호(울산대학교 생명화학공학부) | Soon Ho Hong (School of Chemical Engineering and Bioengineering, University of Ulsan)
• 유익근(울산대학교 생명화학공학부) | Ik-Keun Yoo (School of Chemical Engineering and Bioengineering, University of Ulsan) Corresponding Author