California Wastewater Treatment Operator Practice Exam 2025 – All-in-One Guide to Master Your Certification

Chlorination is a widely used method of disinfection in wastewater treatment primarily because it effectively kills harmful microorganisms, including bacteria, viruses, and certain parasites. The process involves adding chlorine or chlorine compounds to the wastewater, which then reacts with the pathogens, disrupting their cellular functions and leading to their elimination.

Chlorination is favored for its efficiency and the rapidity with which it can reduce microbial levels to meet regulatory standards. Additionally, chlorine is relatively inexpensive and readily available, making it a practical choice for many wastewater treatment facilities.

Other methods of disinfection may serve important roles but do not offer the same broad-spectrum effectiveness against pathogens as chlorination does. For example, filtration may remove suspended solids and some pathogens, but it is not as comprehensive in assuring the destruction of all microorganisms. Oxidation can play a role in breaking down organic materials, but it does not specifically target pathogens in the same way chlorine does. Thermal treatment, while effective for sterilizing, typically requires significant energy and is not practical for all treatment facilities.

Thus, chlorination remains the standard method for disinfection in the wastewater treatment process, balancing effectiveness, cost, and practicality.