Assessment of a novel spiral hydraulic flocculation/sedimentation system by CFD simulation, fuzzy inference system, and response surface methodology

Mohamed Gar Alalm, Mahmoud Nasr, Shinichi Ookawara

Research output: Contribution to journalArticle

16 Citations (Scopus)


Computational fluid dynamics (CFD) was used for hydrodynamic modeling of flocculation and sedimentation experiments in a novel spiral hydraulic flocculation/sedimentation system. The experiments were conducted by different flow rates and different internal geometry to obtain different flocculation times and velocity gradients. In all experiments, the velocity gradient was gradually decreased with depth showing very smooth tapered flocculation which is preferred in hydraulic flocculation. The results of velocity gradient that obtained from the CFD simulation were used to investigate the influence of velocity gradient on turbidity and NOM removal in terms of specific ultraviolet absorbance (SUVA) and dissolved organic carbon (DOC). The experimental results revealed high influence of velocity gradient on reduction of NOM and turbidity. Fuzzy inference system (FIS) and response surface methodology (RSM) were used for modeling the influence of initial SUVA, DOC, and turbidity with velocity gradient and flocculation time on the treatment efficiency. Both methods were suitable for describing the treatment process, however, fuzzy inference model validated the experimental results with higher correlation.

Original languageEnglish
Pages (from-to)137-150
Number of pages14
JournalSeparation and Purification Technology
Publication statusPublished - 1 Sep 2016



  • Computational fluid dynamics (CFD)
  • Dissolved organic carbon (DOC)
  • Hydraulic flocculation
  • Natural organic matter (NOM)
  • Response surface methodology (RSM)

ASJC Scopus subject areas

  • Analytical Chemistry
  • Filtration and Separation

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