The identification and quantification of pathogens in raw and treated wastewater is important for
monitoring the efficiency of treatment processes. An assessment of the efficacy of wastewater
treatment also has implications for influent water quality for drinking water operations. Treated
wastewater effluent may harbor infectious pathogenic microorganisms such as enteroviruses,
Cryptosporidium and Giardia even after standardized treatment processes. The development of
methods to recover Cryptosporidium, Giardia, and enteroviruses from sewage have not been well
established. Consequently, detailed investigations of the impact of treated sewage on surface water
have not been reported. In this study, ultrafiltration and immunomagnetic separation (IMS)
methodologies were optimized to determine and quantify the presence of the target organisms in raw
(influent) and treated sewage at three wastewater treatment facilities: Las Cruces, New Mexico; El Paso, Texas;
and, Juarez, Mexico. One liter influent grab samples were centrifuged and the pellets were processed by
IMS and indirect fluorescent antibody (IFA) for Cryptosporidium and Giardia and the supernatant was
processed by ultrafiltration for phage. Raw sewage seeded recoveries of Cryptosporidium and Giardia
ranged from 42-81% (SD 3-10) and 27-53% (SD 6-10), respectively (n=3 for each site). The recovery
for endogenous phage in raw sewage ranged from 32-50% (SD 10-45) (n=2-4 for each site). Ten liter
effluent grab samples were concentrated by ultrafiltration and the pellets were processed by IMS and
IFA for Cryptosporidium and Giardia and the supernatant was further concentrated by spin column
for phage. Three replicate challenges were done for each site and recoveries of Cryptosporidium and
Giardia ranged from 12-25% (SD 4-14) and 1-30% (SD 0.5-21), respectively. Results from this study
will help evaluate the impact that treated wastewater may have on pathogen loads in environmental
waters. Includes 23 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 300 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 14 |
| Published : | 11/15/2004 |
