Abstract
The reduction of pathogens and indicator organisms through secondary effluent filtration was investigated at six full-scale treatment facilities, ranging in capacity from 0.04 to 1 m3/s (1 to 25 mgd). Grab samples were assayed for pathogens (cultivable enteric viruses, Giardia, and Cryptosporidium) and indicator organisms (coliforms, enterococci, Clostridium perfringens, and coliphages) quarterly under peak flow conditions from each facility over the course of 1 calendar year. Log10 removals resulting from filtration averaged 0.3 to 0.8 log10 for cultivable enteric viruses, 0.4 to 1.5 log10 for protozoan parasites, 0.01 to 3.7 log10 for indicator bacteria, and 0.3 to 1.1 log10 for coliphages. In addition to filter design (cloth, monomedium shallow- or deep-bed, or dual-media filters), differences in reduction of pathogens and indicators could be attributed to the combined effects of hydraulic loading rates, chemical addition practices, backwashing and postbackwashing operating strategies, and the effectiveness of upstream biological treatment and sedimentation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
