• Title/Summary/Keyword: Protein-extracellular polymeric substances (P-EPS)

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The relation between sewage sludge solubilization and extracellular polymeric substances (하수슬러지 가용화와 체외고분자물질(EPS)간의 관계)

  • Jeon, Byeong-Cheol;Nam, Se-Yong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.4
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    • pp.43-49
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    • 2019
  • In order to investigate the relation between sewage sludge solubilization and extracellular polymeric substances(EPS) during alkaline-ultrasonic pretreatment, SCOD/TCOD ratio, solubilization rate, VSS/TS ratio, VSS reduction rate, LB-EPS(Loosely-Bound EPS) and TB-EPS(Tightly-Bound EPS) were measured. At the condition of TS 1.0% and pH 12, solubilization rate increased by 27.7%, LB-EPS as Carbohydrate and Protein increased by 14.6 and 13.3 mg/L/g TS, respectively. Withal, VSS decreased by 26.7% and TB-EPS as Carbohydrate and Protein were extracted by 15.7 and 21.9 mg/L/g TS, respectively. Consequently, the concentrations of organic matter and LB-EPS increased and the trends appeared similarly. In addition, the concentrations trend of decreasing solid matter and extracted TB-EPS also appeared similarly.

Sedimentation and EPS Production by the Change of Dissolved Oxygen Concentration for the Aeration Tank to treat Wastewater with Bacillus sp. (바실러스 미생물을 이용한 하수처리에서 포기조의 DO농도 변화에 따른 EPS 물질생성과 슬러지 침강성에 관한 연구)

  • Lee, Sang-Ho;Son, Han-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.3
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    • pp.627-631
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    • 2007
  • The factors affecting on sludge sedimentation are reported as F/M ratio, ingredient, composition of influent substrate, dissolved oxygen concentration, temperature, pH, filamentous bacteria and SRT. Aeration tank applying Bacillus sp. has an important role for maintaining the dominant microorganism species to make steady progress for spore growth affecting sedimentation. This research aims to investigate the affecting factor for the sedimentation in B3 system and RABC system with aeration tank applying tapered aeration. Extracellular polymeric substances(EPS), protein and carbohydrate can be produced for the extreme condition, that is down to 0.2 mg/L of dissolved oxygen in the aeration tank. This research found out the relation between the sedimentation and the EPS production, especially the ratio of protein/carbohydrate. The spore of Bacillus sp. was formed at the low DO then microorganisms produced EPS. The results showed that the production of EPS was 109.95 mgEPS/gSS at 1.6 mg/L of DO, however it was 131.77 mgEPS/gSS at 0.5 mg/L of DO. The sedimentation was affected by protein content in EPS and the ratio of protein and carbohydrate. The settleability of sludge was not affected by the ratio of protein/carbohydrate in B3 process, meanwhile settleability was affected by the ratio of it in RABC process, respectively.

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Effects of carbon source and nitrogen concentration on the P-EPS and Chl-a production at the MMBR system (MMBR에서 탄소원 종류 및 질소 농도가 S. quadricauda의 P-EPS 및 Chl-a 생성에 미치는 영향)

  • Choi, Yun-Jeong;Sim, Tae-Suk;Hwang, Sun-Jin
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.405-415
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    • 2021
  • MMBR system has been suggested as a promising system to resolve harvesting problems induced from low settling efficiency of microalgae. And recently, a lot of research on reducing fouling at the MMBR system has investigated focused on EPS in many cases. EPS of microalgae mainly consists of polysaccharides and protein components, and is produced through photosynthesis and nitrogen-carbon metabolic pathways. Especially, P-EPS is one of major compounds which occur membrane fouling phenomenon, as its hydrophobic protein components cause floc formation and cake layer accumulation. And it is already known that almost every microalgae can metabolize P-EPS or Chl-a when nitrogen sources as a substrate is insufficient or exhausted situation. With the above backgrounds, uptake rates of P-EPS or Chl-a by Scenedesmus quadricauda according to the type of carbon source and nitrogen concentration were evaluated in order to verify correlation between carbon source vs P-EPS production, and indeed Scenedesmus quadricauda uses P-EPS or Chl-a when the amounts of nitrogen sourc es in the feed is not satisfied. As a result, it was shown that P-EPS and Chl-a production were increased proportional to nitrogen concentration under organic carbon condition. And especially, the amo unts of P-EPS and Chl-a in the cell were diminished with the nitrogen source becomes insufficient or exhausted. Because P-EPS accelerates fouling at the MMBR system, P-EPS degradation by Scenedesmus quadricauda in order to get nitrogen source may contribute to reducing fouling. About a affects of N-consumed Chl-a to the MMBR fouling, more survey is needed. On the contrary, considering the purpose of MMBR system of this study, i.e. harvesting useful high value microalgae efficiently feeding adequate industrial process wastewater, it seems like difficult to maintain satisfied metabolic activity and to harvest with high yield rate using nitrogen-poor MMBR feed.

Comparison of Anoxic/Oxic Membrane Bioreactor - Reverse Osmosis and Activated Sludge Process-Microfiltration-Reverse Osmosis Process for Advanced Treatment of Wastewater (폐수의 고도처리를 위한 무산소/호기형 분리막생물반응조 - 역삼투 공정과 활성슬러지공정 - 정밀여과 - 역삼투 공정의 비교)

  • Roh, Sung-Hee;Kim, Sun-Il;Quan, Hong-hua;Song, Yon-Ho
    • Applied Chemistry for Engineering
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    • v.17 no.5
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    • pp.521-526
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    • 2006
  • A membrane bioreactor (MBR) is an effective tool for wastewater treatment with recycling. MBR process has several advantages over conventional activated sludge process (ASP); reliability, compactness, and quality of treated water. The resulting high-quality and disinfected effluents suggest that MBR process can be suitable for the reused and recycling of wastewater. An anoxic/oxic (A/O) type MBR was applied to simultaneous removal of organics and nutrients in sewage. At first, the efficiency of submerged MBR process was investigated using a hollow fiber microfiltration membrane with a constant flux of $10.2L/m^2{\cdot}h$ at each solids retention time (SRT). Results showed that protein/carbohydrate (P/C) ratio increased and total extracellular polymeric substances (EPS) remained constant with SRT increased. Secondly, A/O type MBR with a reverse osmosis (RO) membrane was employed to treat the municipal wastewater. The performance of A/O type MBR-RO process is better for the treatment of organics and nutrients than ASP-MF-RO process in terms of consistent effluents quality.