Membrane and Water Treatment

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Developing numerical method to predict the removal of Microcystin-LR in a clear well

  • Yeo, Inhee (Civil and Environmental Engineering, Dankook University) ;
  • Park, Yong-Gyun (Environmental Process Engineering Team, GS E&C) ;
  • Kim, Dooil (Civil and Environmental Engineering, Dankook University)
  • Received : 2017.11.05
  • Accepted : 2018.05.07
  • Published : 2018.05.25
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Abstract

Microcystin-LR, one of algal toxins induced by the eutrophication of a reservoir, is known to be harmful to human by adversely affecting our liver and brain. Hypochlorous acid is very efficient to remove Microcystin-LR in a clear well. The previous researches showed that CT, pH and temperature affected removal rate in batch tests. It was noted that hydrodynamic properties of clear well could also influence its removal rate. A mathematical model was built using an axial dispersion reactor model and software was used to simulate the removal rate. The model consisted of the second order differential equations including dispersion, convection, Microcystin-LR reaction with chlorine. Kinetic constants were obtained through batch tests with chlorine. They were $0.430{\times}10^{-3}L/mg/sec$ and $0.143{\times}10^{-3}L/mg/sec$ for pH 7.0 and 8.1, respectively. The axial dispersion reactor model was shown to be useful for the numerical model through conservative tracer tests. The numerical model successfully estimated the removal rate of Microcyctin-LR in a clear well. Numerical simulations showed that a small dispersion number, low pH and long hydraulic retention time were critical for higher removal rate with same chlorine dosage. This model could be used to optimize the operation of a clear well during an eutrophication season.

Keywords

References

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