Inactivation kinetics of adenovirus serotype 2 with monochloramine

The effect of pH (6-10), temperature (10-30 °C), disinfectant concentration (1-11 mg/l as Cl₂), and ammonia nitrogen-to-chlorine molar ratio (1.3-52) on the inactivation kinetics of adenovirus serotype 2 with monochloramine was investigated by performing batch-reactor experiments with synthetic 0.01 M buffer (phosphate or borate) solutions. The inactivation kinetics was independent of monochloramine concentration and ammonia nitrogen-to-chlorine molar ratio but had strong pH dependence, with the rate of inactivation decreasing with increasing pH. The kinetics at pH 6 and 8 were consistent with pseudo-first-order kinetics, while curves at pH 10 were characterized by a lag phase followed by a pseudo-first-order phase. The rate of inactivation increased with increasing temperature-activation energies of 56.5 kJ/mole (pH 8) and 72.6 kJ/mole (pH 10). The results obtained in this study revealed that monochloramine disinfection might not generally provide adequate control of adenoviruses in drinking water at high pH and low temperature.