AWWA WQTC65852

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 concentrationx exposure time, based on time that 10% of influent water reaches the effluent) frombatch reactors do not account for the system hydraulics. As a result, direct quantificationof disinfection performance is preferred to better evaluate Cryptosporidium inactivation.Alternatives include the use of biological (Kim et al., 2002) and non-biological (Chiou etal., 1997; Marinas et al., 1997, 1999; Baeza and Ducoste, 2004) surrogate indicators.Non-biological indicators are of particular interest, since no special biological facilitiesare needed. Direct quantification can be made with the surrogate, since it already takesinto account system hydraulics. The non-biological surrogate indicators that have beenused for chemical disinfection performance are fluorescent dye polystyrene microspheres.These non-biological microspheres have been used by Chiou et al. (1997) to mimicGiardia inactivation with ozone disinfection, by Marinas et al. (1999) to mimicCryptosporidium inactivation with ozone disinfection in batch and full-scale watertreatment plants, and recently by Baeza and Ducoste (2004) to mimic Cryptosporidiumsequential disinfection in batch reactors. All of these studies have shown promisingresults in using microspheres to mimic microbial inactivation. However, no study hasused microspheres with sequential disinfection in a continuous flow system to mimicCryptosporidium inactivation. Hence, this study was performed to evaluate this nonbiologicalapproach in continuous-flow sequential disinfection processes. Includes 19 references, tables, figure.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

8

File Size:

1 file , 220 KB