Student Research

Understanding Disinfection By-Products and Methodologies to Reduce Disinfection By-Products in Water Treatment

The preliminary study of water disinfection began in the mid and late 1800s due to the numerous health hazards due to chemical and microbial water contamination. Although there are many existing methods of water treatment, disinfection by-products (DBPs) have remained as one of many challenges and limitations to safe drinking water. DBPs have been one of the major concerns at the Laguna Vista Elementary School in Oxnard, California. Water samples from the school's water supply revealed an increase in total trihalomethanes (TTHMs), a DBP, which exceeded the regulated maximum contaminant level in 2015, posing health risks to the public. DBP formation results in the chemical reaction between chemical disinfectant agents with the natural organic matter in water. Due to ideal conditions in the formation of THMs, variations of water treatment procedures, such as chemical coagulation, ion exchange, and nanofiltration, in the removal of natural organic matter and bromide will result in decreased DBP formation. Other methodologies to reduce DBPs formation include ozone, adjusting water pH levels, chloramines, and ultraviolet irradiation. Results from these procedures are expected to be lower DBP concentration; however, considering methodology limitations, its effectiveness will vary on the apparatus of the water system, contaminants within the water, and disinfectant. Further research regarding DBP and will classify the proper techniques and technology to reduce TTHM formations.