The effect of the reverse osmosis bottled water storage on its bacteriological, chemical and physical properties

This study aimed to study the effect of the reverse osmosis bottled water storage on its bacteriological, chemical and physical properties. After storing the bottled water for 90 days, the number of bacteria decreased from 49 to 9 CFU/1ml for aerobic bacteria and 3.6-1.1 MPN/100ml for the total number of total coliform. Fecal coliform and Escherichia coli for laboratory W1 ranged 7-16CFU/1ml for the total number of aerobic bacteria and from 1.1-2.2 MPN/100ml for Pseudomonas aeruginosa for the W3 laboratory. After 90 days of storage, an increase in temperature (20.8-43°C), decrease in pH (5-5.4), a high conductivity (125.1-119µS/cm), a rise in dissolved solid salts (77.4-81.2) and total hardness (24.2_29.1) were recorded. Calcium (9.8-12.7), magnesium (3.5-6.5), chlorides (14.7-18.1), sulfate (3.3-5.0), sodium (8.7-12.3), potassium (0.1-0.4) and high nitrate (0.6-3.3) mg/l also were recorded. The bacterial numbers increased during storage process and the storage process also affected all the physical and chemical properties of the bottled water bottles. The results showed significant differences between the studied laboratories as well as between the months at the level. It also showed significant differences between the bacterial and physicochemical treats after 30, 60 and 90 days.