To date, most Cryptosporidium inactivation studies have been done at the bench scale.
The problem with designing full-scale reactors is that the Cts (disinfectant concentration
x exposure time, based on time that 10% of influent water reaches the effluent) from
batch reactors do not account for the system hydraulics. As a result, direct quantification
of disinfection performance is preferred to better evaluate Cryptosporidium inactivation.
Alternatives include the use of biological (Kim et al., 2002) and non-biological (Chiou et
al., 1997; Marinas et al., 1997, 1999; Baeza and Ducoste, 2004) surrogate indicators.
Non-biological indicators are of particular interest, since no special biological facilities
are needed. Direct quantification can be made with the surrogate, since it already takes
into account system hydraulics. The non-biological surrogate indicators that have been
used for chemical disinfection performance are fluorescent dye polystyrene microspheres.
These non-biological microspheres have been used by Chiou et al. (1997) to mimic
Giardia inactivation with ozone disinfection, by Marinas et al. (1999) to mimic
Cryptosporidium inactivation with ozone disinfection in batch and full-scale water
treatment plants, and recently by Baeza and Ducoste (2004) to mimic Cryptosporidium
sequential disinfection in batch reactors. All of these studies have shown promising
results in using microspheres to mimic microbial inactivation. However, no study has
used microspheres with sequential disinfection in a continuous flow system to mimic
Cryptosporidium inactivation. Hence, this study was performed to evaluate this nonbiological
approach in continuous-flow sequential disinfection processes. Includes 19 references, tables, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 220 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 8 |
| Published : | 11/01/2007 |
