Impact of Characteristics of Polymeric Al Coagulants PACl and Alum on Membrane Flux and Fouling of Microfiltration

PACl 및 Alum 응집제 특성이 정밀여과막 투과수량 및 막오염에 미치는 영향

  • 진용철 (건국대학교 공과대학 환경공학과) ;
  • 최양훈 (건국대학교 공과대학 환경공학과) ;
  • 권지향 (건국대학교 공과대학 환경공학과)
  • Published : 2011.04.15

Abstract

The objectives of this research are to investigate coagulation efficiencies of two coagulants l.e., alum and polyaluminum chloride and to understand effects of the coagulants on membrane fouling in microfiltration. The turbidity of supernatant from alum coagulation was increased with increasing doses whereas the turbidity from PACl coagulation was maintained at the low values. The observed injection volume of PACl for the same removal was approximately 30 percent less than alum, which produced a low sludge volume. The settling velocity of PACl flocs was greater than alum flocs. The results corresponded well with floc size measurements. Flux decline from alum coagulation was significant due in part to small sizes of flocs. At the low dose, alum floc had less specific cake resistance than PACl floc. However, as the dosage was increased, the increases in specific cake resistances of alum was substantial. Alum coagulation pretreatment needs careful operation to reduce membrane fouling by flocs. In general, PACl coagulants were more effective than alum coagulants for pretreatment of membrane processes because PACl showed the better performance in coagulation and membrane fouling.

Keywords

References

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