AWWA RSP64377

This slide presentation outlines a study on measuring the inactivation kinetics of the ammonia oxidizing bacteria(AOB) Nitrosomonas europaea in bench-scaleexperiments in the presence of chlorine andmonochloramine, generate CT values, compare to E. coli CT value, and explore the disinfection kinetics of AOB inthe presence of corrosion debris, soil material,and wastewater, comparing those results tothe kinetics obtained in pure water. A bench scale study is outlined in the presentation that had the following conclusions: in pure water, the use of free chlorine produced 6logs of AOB inactivation at a CT value of 1.3mg.min/L;monochloramine yielded 4 logs of AOB inactivation ata CT value of 10.5 mg.min/L;the monochloramine inactivation kinetics of AOB aresimilar to those of E. coli, but AOB are more resistant to chlorine than E. coli; and, corrosion debris, soil material, and wastewater hadno statistically significant (p<0.05) impact on theinactivation AOB. A second study is outlined with the objectives of: at pilot-scale, monitoring AOB in the presenceof various disinfectants and source waterquality conditions,varying specific ultraviolet absorbance (SUVA) andbromide levels; and,monitoring AOB levels at pilot-scale by usingthe MPN cultivation method (25 to 30 days ofincubation) and a molecular method (PCR amplification of the amoAgene). Study 2 conclusions included:the testing phase with (high) 0.8-mg/L bromide, (high) >3.16 Lmg-1 m-1 SUVA is the only one during which HPC were detectedat the effluent of all treatment trains;competition for chlorine between natural organic matter (NOM), bromide and microbialinactivation may have affected disinfection;however, AOB were not detected either by the MPN culturetechnique or the molecular method in any of the phases;nitrite concentrations were low, suggesting that nitrification didnot occur over the entire testing period, consistent with the absence of AOB in the simulated distribution systems;adequate treatment prevents nitrification in distribution systems; and,low HPCs suggest absence of AOBs. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

03/01/2007

Number of Pages:

31

File Size:

1 file , 880 KB