Removal of viruses from surface water and secondary effluents by sand filtration.
The filtration of phi X 174, MS2, and T4 bacteriophages out of tap water and secondary effluents was performed by rapid sand filtration. The viruses were characterized, and the influence of their microscopic characteristics on filterability was examined by comparing retention values, residence times, attachment, and dispersion coefficients calculated from an advection-dispersion model and residence time variation. The only factor observed to influence retention was virus size, such that the larger the virus, the better the retention. The difference was due to the more effective transport of viruses inside the media, an observation that runs counter to currently accepted filtration theory. Cake formation on top of the filter during the initial stages of secondary effluent filtration significantly increased headloss, eventually resulting in shorter filtration cycles. However, deep filters contain buffering zones where the pressure drop is amortized, thus allowing for continued filtration. After the effluent passed through the buffer zone, regular filtration was observed, during which considerable virus retention was achieved.
Aronino
Revital
R
Unit of Environmental Engineering, Faculty of Engineering Sciences, Ben-Gurion University of the Negev, PO Box 653, Beer-Sheva 84105, Israel. aroninor@bgu.ac.il
Dlugy
Christina
C
Arkhangelsky
Elizabeth
E
Shandalov
Semion
S
Oron
Gideon
G
Brenner
Asher
A
Gitis
Vitaly
V
D001435:Bacteriophages / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation; D005374:Filtration / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D009391:Nephelometry and Turbidimetry; D012822:Silicon Dioxide; D013499:Surface Properties; D013997:Time Factors; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D014881:Water Supply
D012822:Silicon Dioxide