What chemical is used in both water purification and sewage treatment to give long-term disinfection?

Question

Quizplus · Accepted Answer

Chlorine is commonly used in both water purification and sewage treatment as a disinfectant to kill bacteria and viruses. It provides long-term disinfection by remaining in the water supply and continuing to kill any new bacteria or viruses that may enter the system. Fluorine is not typically used for disinfection, but rather to prevent tooth decay. Activated charcoal is used for filtration, but not disinfection. Copper sulfate is sometimes used in water purification, but primarily for algae control, not disinfection.

What Chemical Is Used in Both Water Purification and Sewage