Effects of Boiling and Storage on Water Quality of Tap Water, Spring Water, and Bottled Water

This study conducted a systematic and comparative investigation on how boiling and storage affect the water quality of tap water, spring water, and bottled water, focusing on the molecular cluster size, hardness, nitrite content, and pH value. The findings revealed that boiling reduces water hardness and the size of molecular clusters in both tap and spring water, with these effects lasting for several days. Boiling also decreases the nitrite content, but after one day of storage, the nitrite levels in the boiled water tend to rebound to higher levels than those in un-boiled water. However, boiled spring water stored in a closed bottle maintained lower nitrite levels than un-boiled water for up to seven days. The boiling also slightly increased the pH values of tap and spring water, and its effect could last for several days. There were correlative changes in the water hardness, cluster size, nitrite content, and pH value due to boiling. These results suggest that boiling is beneficial for drinking water because it can improve the water quality for healthy drinking. Additionally, bottled water stored for less than a year remains safe to drink as its quality does not significantly decline in that period.