The Sedimentation of Cryptosporidium Oocysts and Its Impact on Filter Backwash Water Recycling

EPA Grant Number: U915198
Title: The Sedimentation of Cryptosporidium Oocysts and Its Impact on Filter Backwash Water Recycling
Investigators: Rhyne, Melissa D.
Institution: Georgia Institute of Technology
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 1997 through January 1, 1999
Project Amount: $68,000
RFA: STAR Graduate Fellowships (1997) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Civil/Environmental Engineering


The objective of this research project is to determine the general settling characteristics of Cryptosporidium to assess removal through sedimentation and its impact on filter backwash water recycling. Through collaboration with other researchers and the Centers for Disease Control in Atlanta, the findings from this research will be incorporated into developing a noninfectious surrogate and modeling the fate and transport of Cryptosporidium in natural water and treatment scenarios.


The first phase of this research project will consist of laboratory-scale column studies on the sedimentation efficiency of Cryptosporidium oocysts and latex beads. Initial studies will measure the settling velocities of the oocysts and beads spiked in tap water, under controlled pH and ionic strength conditions. Concentrations of the oocysts and beads will be determined by flow cytometry at various depths along the column to assess the settling velocities. Column studies will then be conducted using filter backwash water spiked with oocysts and beads to assess the interaction of the Cryptosporidium oocysts with the particles in backwash water. The backwash water will be obtained either from the city of Atlanta pilot plant or a local water treatment plant. In the second phase of this research project, I will determine the surface characteristics of the Cryptosporidium oocysts. Zeta potential will be measured using a zeta meter to indicate the surface charge on the oocysts and beads. Also, I will quantify the hydrophobicity of the oocysts and beads.

Supplemental Keywords:

fellowship, Cryptosporidium, oocysts, sedimentation, backwash water recycling., RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Water, Environmental Chemistry, Health Risk Assessment, Civil/Environmental Engineering, Biochemistry, Drinking Water, cryptosporidium parvum oocysts, fate and transport, health effects, filter backwash water recycling, sediment transport, other - risk assessment, treatment, cryptosporidium

Progress and Final Reports:

  • 1997
  • Final