TABLE 2

Comparison of α values for C. parvum derived from various porous media under comparable experimental conditions

StudyC. parvum activationPorous mediumU (m/day)d (mm)Column length (cm)SolutionpHα
This studyUV inactivatedLimestone sand1.30.551010 mM NaCl8>3.93a
Pang et al. (19)NoninactivatedAlluvial sand∼10.78221 mM NaCl70.05–0.06
Abudalo et al. (44)Formalin inactivatedFerric oxyhydroxide-coated quartz sand0.760.92100.1 mM NaCl5.6–5.80.26
Park et al. (45)NoninactivatedOttawa sand0.710.53203 mM NaCl70.36
Hijnen et al. (46)NoninactivatedFluvial gravel (NOM,b Fe-ox content)0.90.550River Meuse waterc8.0–8.40.40d
Harter et al. (42)NoninactivatedAlluvial sand0.70.4210Degassed tap watere7.90.56f
  • a Theoretical value for breakthrough below sample limit of detection (3 oocysts/ml).

  • b NOM, naturally occurring organic matter.

  • c Electrical conductivity, 569 to 574 μS/cm.

  • d Correction by Hijnen et al. (47).

  • e Electrical conductivity, 220 μS/cm.

  • f Calculated by Park et al. (45) using the method of Tufenkji and Elimelech (36).