Comparison of coagulation and MIEX pre-treatment processes for bacterial and turbidity removal, utilizing real-time optical monitoring techniques

Environ Technol. 2014 Mar-Apr;35(5-8):1038-45. doi: 10.1080/09593330.2013.859737.

Abstract

Jar testing and flow cytometry were used in conjunction with photometric dispersion analysis (PDA) to assess conventional alum coagulation with and without magnetic ion exchange (MIEX) pre-treatment for turbidity and bacterial removal capacity. Treatment assessment included powdered activated carbon (PAC) and pre-chlorination of the MIEX-treated raw water. Floc particles were subjected to shear forces after settling and re-suspended to gauge bacterial release potential, floc breakage and re-aggregation. MIEX in conjunction with alum coagulation achieved improved coagulation as measured by PDA but did not increase bacterial log removal value (LRV) in comparison with conventional coagulation. Pre-chlorination and PAC addition were seen to improve bacterial removal and coagulation, respectively, but were less effective for bacterial LRVs when they were used in conjunction during coagulation.

Publication types

  • Comparative Study

MeSH terms

  • Alum Compounds / chemistry
  • Bacteria / metabolism
  • Carbon / chemistry
  • Chlorine / chemistry
  • Flocculation
  • Flow Cytometry
  • Ion Exchange*
  • Magnetics
  • Nephelometry and Turbidimetry / methods
  • Optics and Photonics / methods
  • Photometry
  • Shear Strength
  • Waste Disposal, Fluid / methods*
  • Water Microbiology*
  • Water Pollutants, Chemical / chemistry
  • Water Purification / methods

Substances

  • Alum Compounds
  • Water Pollutants, Chemical
  • aluminum sulfate
  • Chlorine
  • Carbon