Journal of Korean Society of Water and Wastewater (상하수도학회지)

The Korean Society of Water and Wastewater (대한상하수도학회)
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The effect of iron oxide ballasted flocculant on the activated sludge settleability and dewaterability

산화철계 가중응집제가 활성슬러지의 침전성 및 탈수성에 미치는 영향

  • Yang, Hyeji (Department of Environmental IT Convergence Engineering, Chungnam National University) ;
  • Kim, Yongbum (Department of Environmental IT Convergence Engineering, Chungnam National University) ;
  • Choi, Younggyun (Department of Environmental IT Convergence Engineering, Chungnam National University)
  • 양혜지 (충남대학교 환경IT융합공학과) ;
  • 김용범 (충남대학교 환경IT융합공학과) ;
  • 최영균 (충남대학교 환경IT융합공학과)
  • Received : 2021.06.22
  • Accepted : 2021.07.19
  • Published : 2021.08.15
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Abstract

The ballasted flocculation effects of the mill scale and magnetite on activated sludge were investigated. Both ballasted flocculants (BF) could remarkably improve the sludge settleability in terms of zone settling velocity (ZSV) and sludge volume index (SVI). With the BF dosage of 0.2 to 2.0 g-BF/g-SS, the magnetite particles showed better efficiency on improving settling behavior of activated sludge than the mill scale due to higher surface area and hydrophobic property. The efficiency of SVI30 with magnetite injection was 2.5 to 11.3% higher than mill scale injection and that of the ZSV appreciated from 23.7% to 44.4% for magnetite injection. Averaged floc size of the BF sludge with magnetite dosage (0.5 g-BF/g-SS) was 2.3 times higher than that of the control sludge. Dewaterability of the sludge was also greatly improved by addition of the BF. The specific resistance to filtration (SRF) was reduced exponentially with increasing the dosage of BF. However, the BF's particle size effect on the SRF looks to be marginal. Consequently, for improving the dewaterability, the BF played a physical role to remove the pore water of the biological flocs by intrusive attachment and a chemical role to induce aggregation of the flocs by charge neutralization.

Keywords

Acknowledgement

본 연구는 (주)포스코건설의 연구비 지원에 의해 수행되었으며, 이에 감사드립니다. (과제번호 2019-1660-01)

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