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Evaluations of Coagulation Process for Membrane Pre-treatment using Floc Growth Rate Analyzer

응집 플록 성장률 측정기를 이용한 멤브레인 공정의 전처리 응집공정 평가

  • Son, Hee-Jong (Water Quality Institute, Busan Water Authority) ;
  • Kim, Sang-Goo (Water Quality Institute, Busan Water Authority) ;
  • Kim, Do-Hwan (Water Quality Institute, Busan Water Authority) ;
  • Kang, So-Won (Department of Bio-chemical Engineering, Friedrich-Alexander University) ;
  • Choi, Young-Ik (Department of Environmental Engineering, Dong-A University)
  • 손희종 (부산광역시 상수도사업본부 수질연구소) ;
  • 김상구 (부산광역시 상수도사업본부 수질연구소) ;
  • 김도환 (부산광역시 상수도사업본부 수질연구소) ;
  • 강소원 (프리드리히-알렉산더대학교 생명화학공학과) ;
  • 최영익 (동아대학교 환경공학과)
  • Received : 2015.08.13
  • Accepted : 2016.02.11
  • Published : 2016.02.29

Abstract

In this study, we have investigated to find optimal pre-treatment flocculation condition by analyzing the floc growth rate with mixing conditions and the membrane permeation flux for pre-treatment step of the membrane process. The higher mixing intensity showed a constant floc size index (FSI) values, and lower mixing intensity increased the degree of dispersion of the FSI values. Results of comparing the distribution characteristics of the FSI value and the permeation flux were more effective in increasing flux when the FSI values were 0.2 or higher. The degree of dispersion of FSI was relatively large in 40 rpm mixing condition compared to 120 rpm. In 40 rpm mixing condition, it decreased the permeation flux compared to 120 rpm because various sizes of flocs were distributed. Coagulation-UF membrane process enhanced 30%~40% of the flux rate compare to UF alone process, and the coagulation-MF process increased up to 5% of the flux rate compare to MF alone process. Pre-treatment, that is, coagulation process, has been found to be less effects on relatively larger pore size for MF membrane. For UF membrane, the flux was a little bit same when applying only the rapid mixing process or rapid mixing with slow mixing processes together. In case of MF membrane, the flux was improved when rapid mixing process applied with slow mixing process together.

Keywords

Membrane process;Coagulation;Flocculation intensity;Floc size index (FSI);Membrane pore size

Acknowledgement

Supported by : 동아대학교

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