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Treatment of High Concentration Organic Wastewater with a Sequencing Batch Reactor (SBR) Process Combined with Electro-flotation as a Solids-liquid Separation Method

Choi, Younggyun;Park, Minjeong;Park, Mincheol;Kim, Sunghong

  • Received : 2014.11.21
  • Accepted : 2014.12.11
  • Published : 2014.12.31

Abstract

Operation characteristics of the sequencing batch reactor (SBR) process with electro-flotation (EF) as a solid liquid separation method (EF-SBR) were investigated. EF-SBR process showed excellent solid-liquid separation performance which enabled to separate biosolids from liquid phase within 30 min and to extend cyclic reaction time. Although influent organic loading rate was increased stepwise from 5 to 15 g COD/day, food to microorganisms (F/M) ratio could be maintained about 0.3 g COD/g VSS/day in EF-SBR because biomass concentration could be easily controlled at desired level by EF. However, it was impossible to increase biomass concentration at the same level in control SBR (C-SBR) process because solid-liquid separation by gravity settling showed a limitation at higher mixed liquor suspended solids (MLSS) concentration with 60 min of settling time. Total chemical oxygen demand (TCOD) removal efficiency of EF-SBR process was not decreased although influent organic loading rate became 3 times higher than initial value. However, it was seriously deteriorated in C-SBR process after increasing the rate over 10 g COD/day, which was accounted for insufficient organic removal by relatively higher food to microorganisms (F/M) ratio as well as biosolids wash-out by a limitation of gravity sedimentation.

Keywords

Electro-flotation (EF);Food to microorganisms (F/M) ratio;Sequencing batch reactor (SBR);Thickening

References

  1. Hait S, Tare V. Wastewater treatment by high-growth bioreactor integrated with settling-cum-membrane separation. Desalination 2011;270:233-240. https://doi.org/10.1016/j.desal.2010.11.050
  2. Chen X, Chen G, Yue PL. Novel electrode system for electroflotation of wastewater. Environ. Sci. Technol. 2002;36:778-783. https://doi.org/10.1021/es011003u
  3. Kim JH, Kim HS, Lee BH. Combination of sequential batch reactor (SBR) and dissolved ozone flotation-pressurized ozone oxidation (DOF-PO2) processes for treatment of pigment processing wastewater. Environ. Eng. Res. 2011;16:97-102. https://doi.org/10.4491/eer.2011.16.2.97
  4. Manjunath NT, Mehrotra I, Mathur RP. Treatment of wastewater from slaughterhouse by DAF-UASB system. Water Res. 2000;34:1930-1936. https://doi.org/10.1016/S0043-1354(99)00337-1
  5. Chen X, Chen G, Yue PL. Separation of pollutants from restaurant wastewater by electrocoagulation. Sep. Purif. Technol. 2000;19:65-76. https://doi.org/10.1016/S1383-5866(99)00072-6
  6. Hosny AY. Separating oil from oil-water emulsions by electroflotation technique. Separ. Technol. 1996;6:9-17. https://doi.org/10.1016/0956-9618(95)00136-0
  7. Alexandrova L, Nedialkova T, Nishkov I. Electroflotation of metal ions in wastewater. Int. J. Miner. Process. 1994;41:285-294. https://doi.org/10.1016/0301-7516(94)90034-5
  8. Burns SE, Yiacoumi S, Tsouris C. Microbubble generation for environmental and industrial separations. Sep. Purif. Technol. 1997;11:221-232. https://doi.org/10.1016/S1383-5866(97)00024-5
  9. Chen G, Chen,X, Yue PL. Electrocoagulation and electroflotation of restaurant wastewater. J. Environ. Eng. 2000;126:858-863. https://doi.org/10.1061/(ASCE)0733-9372(2000)126:9(858)
  10. Poon CPC. Electroflotation for groundwater decontamination. J. Hazard. Mater. 1997;55:159-170. https://doi.org/10.1016/S0304-3894(97)00013-7
  11. Vu TP, Vogel A, Kern F, Platz S, Menzel U, Gadow R. Characteristics of an electrocoagulation-electroflotation process in separating powdered activated carbon from urban wastewater effluent. Sep. Purif. Technol. 2014;134:196-203. https://doi.org/10.1016/j.seppur.2014.07.038
  12. Khelifa A, Aoudj S, Moulay S, Petris-Wery MD. A one-step electrochlorination/electroflotation process for the treatment of heavy metals wastewater in presence of EDTA. Chem. Eng. Process: Process Intensif. 2013;70:110-116. https://doi.org/10.1016/j.cep.2013.04.013
  13. Balla W, Essadki AH, Gourich B, Dassaa A, Chenik H, Azzi M. Electrocoagulation/electroflotation of reactive, disperse and mixture dyes in an external-loop airlift reactor. J. Hazard. Mater. 2010;184:710-716. https://doi.org/10.1016/j.jhazmat.2010.08.097
  14. Merzouk B, Madani K, Sekki A. Using electrocoagulation-electroflotation technology to treat synthetic solution and textile wastewater, two case studies. Desalination 2010;250:573-577. https://doi.org/10.1016/j.desal.2009.09.026
  15. Choi YG, Kim SH, Kim HJ, Kim YJ, Chung TH. Effects of current density and electrode material on the dewaterability of the thickened activated sludge by electro-flotation. J. Chem. Technol. Biotechnol. 2009;84:1493-1498. https://doi.org/10.1002/jctb.2207
  16. Barbusinski K, Koscielniak H. Influence of substrate loading intensity on floc size in activated sludge process. Water Res. 1995;29:1703-1710. https://doi.org/10.1016/0043-1354(94)00326-3

Acknowledgement

Supported by : Daegu University