What is the chlorine residual typically used to disinfect large full storage tanks?

The typical chlorine residual used to disinfect large full storage tanks is around 10 mg/L. This level is considered effective for ensuring that pathogenic bacteria and other microorganisms are adequately killed during the disinfection process. A chlorine concentration of 10 mg/L strikes a balance between efficacy and safety, ensuring that the water is sanitized without introducing excessive chlorine that could lead to taste and odor issues or potential health concerns.

Using a concentration of 10 mg/L is generally sufficient to achieve the necessary log reduction of pathogens, while also maintaining an appropriate contact time, which is key to effective disinfection. Higher concentrations like 15 mg/L or 20 mg/L may not be necessary for effective disinfection and could lead to complications such as exceeding acceptable limits for chlorine in drinking water or creating unwanted byproducts. Meanwhile, a lower concentration like 5 mg/L might not provide enough disinfection power, especially in larger volumes of water where pathogen levels could be significant.

Therefore, a chlorine residual of 10 mg/L is the standard choice for effective disinfection of large full storage tanks.