disinfection

Researchers have achieved a breakthrough in improving the efficiency of an electrochemical reaction that produces hydrogen peroxide -- a vital chemical for industrial applications such as disinfection, bleaching, and sewage treatment.

While authorities said the health of the remaining 78 mammals in the zoo was "normal", the mammals section has been closed since 14 October for disinfection and cleaning.

THM4 was the most abundant, and additionally, various unregulated disinfection byproducts were produced.

According to the Centers for Disease Control and Prevention, "Chronic exposure to disinfection byproducts may increase risk of cancer. Humans exposed to unusually large amounts of some disinfection byproducts could experience liver damage and decreased nervous system activity."

During the lab process, control reactors containing either only free chlorine or only petroleum hydrocarbons produced significantly lower or no detectable levels of disinfection byproducts, which indicated that the presence of petroleum hydrocarbons and free chlorine together was responsible for the elevated disinfection byproduct concentrations.