This study aimed at evaluating the manual agitation effect on inactivation efficiency of thermotolerant coliforms of water bottles submitted to solar disinfection. Agitated bottles and non-agitated bottles were exposed to sunlight from 9:00 a.m. to 3:00 p.m. Dissolved oxygen (DO) and thermotolerant coliforms concentrations were analyzed hourly. The solar disinfection improved the water quality, reducing thermotolerant coliforms concentration by 4 logs (from 1.0 x 10(6) to 2.6 x 10¹MPN/100 mL). With the manual agitation, there was considerable oxygenation in the water samples (maximum of 6.61 mg/L in samples with manual agitation and of 5.56 mg/L for those without agitation), but the increase in DO had no significant effect on the inactivation of thermotolerant coliforms (p>0.05).
bacterial decay; PET bottles; solar radiation; dissolved oxygen
