Journal of Korean Society of Water and Wastewater (상하수도학회지)

The Korean Society of Water and Wastewater (대한상하수도학회)
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Pre-treatment of oily wastewater using a coagulation-DAF process with slit-nozzle

슬릿노즐기반 응집·공기부상공정을 통한 유류폐수 전처리

  • Choi, Sangki (School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology) ;
  • Kim, Youngmo (School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology)
  • 최상기 (광주과학기술원, 지구환경공학부) ;
  • 김영모 (광주과학기술원, 지구환경공학부)
  • Received : 2018.09.17
  • Accepted : 2018.10.12
  • Published : 2018.12.17
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Abstract

Large amounts of oily wastewater discharged from various industrial operations (petroleum refining, machinery industries and chemical industries) cause serious pollution in the aquatic environment. Although dissolved air flotation (DAF) separating oil pollutants using microbubbles represents current practice, bubble size cannot be selectively controlled, and lots of power is required to generate microbubbles. Therefore, to investigate performance of the DAF process, this study examined the distribution of different sizes of microbubbles resulting from changes in physical shear force via modifying shapes of a slit-nozzle without an additional power supply. Three types of slit-nozzles (different angle, shape and length of the slit-nozzle) were used to analyze the distribution of bubble size. At a slit angle of $60^{\circ}$, shear force was 4.29 times higher than a conventional slit, and particle size distribution (PSD) in the range between 2 and $20{\mu}m$ more than doubled. Treatment efficiency of synthetic oily wastewater through the coagulation-DAF process achieved 90% removal of COD by injecting $FeCl_3$ and PACl of 250 mg/L and 100 mg/L, respectively, and the same performance resulted using $FeCl_3$ of 200 mg/L and PACl of 80 mg/L employing a slit-nozzle angle of $60^{\circ}$. This study shows that a coagulation-DAF process using a modified slit-nozzle can improve the pre-treatment of oily wastewater.

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References

  1. Al-Shamrani, A.A., James, A., and Xiao, H. (2002). Destabilisation of oil-water emulsions and separation by dissolved air flotation, Water Res., 36(6), 1503-1512. https://doi.org/10.1016/S0043-1354(01)00347-5
  2. WEF and APHA. (2005). Standard methods for the examination of water and wastewater, American Public Health Association, Washington, DC, USA. (2005). Standard methods for the examination of water and wastewater, Am. J. Public Health, Washington, DC, USA.
  3. Gryta, M., Karakulski, K., and Morawski, A.W. (2001). Purification of oily wastewater by hybrid UF/MD, Water Res., 35(15), 3665-3669. https://doi.org/10.1016/S0043-1354(01)00083-5
  4. Han, M., Kim, T.I., and Kim, J. (2007). Effects of floc and bubble size on the efficiency of the dissolved air flotation (DAF) process, Water Sci. Technol., 56(10), 109-115. https://doi.org/10.2166/wst.2007.779
  5. Hanotu, J., Bandulasena, H.H., Chiu, T.Y., and Zimmerman, W.B. (2013). Oil emulsion separation with fluidic oscillator generated microbubbles, Int. J. Multiph. Flow, 56, 119-125. https://doi.org/10.1016/j.ijmultiphaseflow.2013.05.012
  6. Hasegawa, H., Nagasaka, Y., and Kataoka, H. (2008). Electrical potential of microbubble generated by shear flow in pipe with slits, Fluid Dyn. Res., 40(7-8), 554. https://doi.org/10.1016/j.fluiddyn.2007.12.007
  7. Kim, I.S. and Park S.C. (1993). Emulsified oily wastewater treatment by MHD water treatment device, J. Korean Soc. Marine Eng., 17(4), 246-253.
  8. Luthy, R.G., Selleck, R.E., and Galloway, T.R. (1978). Removal of emulsified oil with organic coagulants and dissolved air flotation, J. Water Pollut. Control. Fed., 331-346.
  9. Ministry of Environment. (2010). A study on exploration and reduction of ecotoxic causes in industrial wastewater(III), 266-277.
  10. Poulopoulos, S.G., Voutsas, E.C., Grigoropoulou, H.P., and Philippopoulos, C.J. (2005). Stripping as a pretreatment process of industrial oily wastewater, J. Hazard. Mater., 117(2-3), 135-139. https://doi.org/10.1016/j.jhazmat.2004.08.033
  11. Shammas, N.K., Wang, L.K., and Hahn, H.H. (2010). Fundamentals of wastewater flotation. In Flotation Technology, Humana Press, Totowa, NJ, 121-164.
  12. Suzuki, Y., and Maruyama, T. (2005). Removal of emulsified oil from water by coagulation and foam separation, Sep. Sci. Technol., 40(16), 3407-3418. https://doi.org/10.1080/01496390500423755
  13. Temesgen, T., Bui, T.T., Han, M., Kim, T.I., and Park, H. (2017). Micro and nanobubble technologies as a new horizon for water-treatment techniques: A review, Adv. Colloid Interface Sci., 246, 40-51. https://doi.org/10.1016/j.cis.2017.06.011
  14. Younker, J.M., and Walsh, M.E. (2014). Bench-scale investigation of an integrated adsorption-coagulation-dissolved air flotation process for produced water treatment, J. Environ. Chem. Eng., 2(1), 692-697. https://doi.org/10.1016/j.jece.2013.11.009
  15. Zabel, T. (1985). The advantages of dissolved‐air flotation for water treatment, J. Am. Water Work Assoc., 77(5), 42-46.
  16. Zerva, C., Peschos, Z., Poulopoulos, S.G., and Philippopoulos, C.J. (2003). Treatment of industrial oily wastewaters by wet oxidation, J. Hazard. Mater., 97(1-3), 257-265. https://doi.org/10.1016/S0304-3894(02)00265-0
  17. Zhou, Y.B., Tang, X.Y., Hu, X.M., Fritschi, S., and Lu, J. (2008). Emulsified oily wastewater treatment using a hybrid-modified resin and activated carbon system, Sep. Purif. Technol., 63(2), 400-406. https://doi.org/10.1016/j.seppur.2008.06.002
  18. Zouboulis, A.I., and Avranas, A. (2000). Treatment of oil-in-water emulsions by coagulation and dissolved-air flotation, Colloid. Surf. A., 172(1-3), 153-161. https://doi.org/10.1016/S0927-7757(00)00561-6