'Primary' antibiotics in wastewater treatment plants.

There are anywhere from 5 to 8 priority antibiotics in typical wastewater treatment plants (WWTPs) whose concentrations exceed the maximum allowed, out of 12 priority antibiotics designated by the World Health Organization as the species to pose severe health hazard than others. If the priority antibiotics to deal with could be reduced to just one or two, such reduction would greatly simplify the construction and operation of the treatment plants. Introduced here is a concept of 'primary' antibiotic, the abatement of which ensures mitigation of all the other priority antibiotics in the wastewater. A criterion for determining primary antibiotic is developed. For a demonstration of the approach, the wastewater systems treated with solar-based photocatalysts are considered. The criterion reveals that the primary antibiotic in the typical European WWTP as well as in the typical municipal and hospital wastewater is ciprofloxacin, whereas the typical industrial wastewater contains ciprofloxacin and oxytetracycline.