What is the recommended concentration of a water chlorine solution for disinfection of potable water for a duration of 24 hours?

The recommended concentration of a water chlorine solution for the disinfection of potable water over a duration of 24 hours is typically around 500 parts per million (ppm). This concentration is effective in ensuring that harmful pathogens present in the water are adequately killed, which is crucial for making water safe for drinking.

Using 500 ppm allows for a sufficient chlorine residual that can maintain its disinfecting properties throughout the entire 24-hour period. This level of concentration helps address common waterborne pathogens, providing a strong assurance of microbial safety while preventing the growth of potentially harmful bacteria or viruses.

Concentrations lower than this, such as 200 ppm or 300 ppm, may not provide adequate disinfection, especially if there are high levels of contaminants in the water. A concentration of 700 ppm is generally excessive for potable water disinfection and could lead to adverse health effects if consumed, such as irritation or toxicity.

Therefore, maintaining a concentration of around 500 ppm for a 24-hour contact time strikes a balance between effective disinfection and safety for human consumption.