The use of activable tracers in the evaluation of the performance of wastewater treatment plants.

The use of stable, activable tracers has been studied in applications to establish the performance of waste treatment plants and detect causes of irregular or improper functioning of individual plant processes. Various soluble tracers were evaluated, among them indium, scandium, and bromine. The inert tracers were compared with dye tracers and were found to be superior in turbid liquids and to give more quantitative information. On the other hand dye tracers are more convenient for rapid visible indication of their arrival whereas activable tracers require collection and removal to a neutron source, such as a reactor, for indication. Activable tracers are relatively simple to apply and the cost per test is reasonable.