Grantee Research Project Results
Impact of Bacteria and Dosing Frequency on the Removal of Virus Within Intermittently Dosed Biological Filters
EPA Grant Number: U915034Title: Impact of Bacteria and Dosing Frequency on the Removal of Virus Within Intermittently Dosed Biological Filters
Investigators: Emerick, Robert W.
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 1996 through January 1, 2002
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1996) RFA Text | Recipients Lists
Research Category: Fellowship - Environmental , Academic Fellowships , Safer Chemicals
Objective:
The specific objectives of this research project were to: (1) investigate the impacts of improved design (e.g., medium type, medium depth) and operation (e.g., dosing frequency) on virus removal within intermittently dosed biological filters; and (2) investigate the role of bacteria in removing virus within intermittently dosed biological filters.
Approach:
Six dosing frequencies (1, 2, 3, 12, 24, and 48 times/day) were investigated for their impact on the removal of MS2 virus from primary effluent in laboratory-scale sintered glass filter columns. The filters were operated both with and without the presence of bacteria on the sintered glass. The hydraulic application rate was 0.064 m/day. The effective size of the medium was 1.5 mm, with a uniformity coefficient of 1.0. The internal surface area was 87,050 m2/m3. Filter depth was 152 mm. At the constant hydraulic application rate, increasing the dosing frequency from 1 to 48 times/day resulted in an increase in the viral removal from 0.3 to 2.3 log in the absence of bacteria, and from 0.8 to 4.6 log in the presence of bacteria. At a dosing frequency of 48 times/day, removing the top 25 mm of the medium resulted in virus removal performance similar to that of the bacteria-free system. Filter depth also appeared to influence virus removal, with a greater depth resulting in higher virus removal.