A decrease in temperature will have what effect on disinfection?

A decrease in temperature negatively affects the efficiency of disinfection processes, particularly those that rely on chemical agents or biological activity. Many disinfectants, like chlorine and ozone, are less effective at lower temperatures because the chemical reactions that cause them to kill pathogens proceed more slowly when it’s colder.

The reason longer contact time is necessary is that the reduced kinetic energy at lower temperatures slows down the disinfection reactions. Therefore, to achieve the same level of pathogen reduction, operators need to increase the amount of time the disinfectant is in contact with the contaminants. This longer contact time allows the disinfection process to compensate for the decreased effectiveness caused by the colder temperature, ensuring that enough time is allowed for the requisite chemical reactions or biological processes to occur effectively.

Understanding these principles is crucial for wastewater operators in ensuring that disinfection protocols achieve the desired results, particularly when seasonal temperature variations can impact treatment efficacy.