PH06 Agrochemicals, Pesticides, Pharmaceuticals
Exhibit Hall
8:00 AM - Thursday
(PH045) Pharmaceutical Fate in Pilot and Bench Scale Drinking Water Treatment Plants.
Ten Eyck, C1, Doucette, W1, McNeill, L1, Ericson, J2, 1 Utah State University, Logan, UT, USA2 Pfizer Global Research and Development, Groton, CT, USA
ABSTRACT- Bench and pilot scale drinking water treatment plants (DWTP) were used to examine the potential removal of four pharmaceutical-like compounds: caffeine, salicylic acid, trovafloxacin mesylate, and estradiol. The compounds were selected to be representative of a variety of pharmaceuticals in terms of their physical/chemical properties (i.e. charge and hydrophobicity) and their expected fate within drinking water treatment facilities. The following treatment processes were evaluated in both the bench and pilot-scale systems: ozonation, coagulation/flocculation, sedimentation, and filtration. The bench scale system (0.030 L/min) was designed to operate within the recommended operation parameters of a full-scale system where possible. The major advantage of the bench-scale system in addition to its operationally convenient size was that radiolabeled chemicals could be used for more accurate mass balance determinations. Non-labeled compounds were used in the pilot plant (23-26 L/min) along with hydraulic tracers such as fluorescein. The test compounds were added to the influents of each system to yield concentrations from 1 to 200 ppb depending on the analytical detection limits. Samples were collected over time at the influent and effluent of each treatment unit for a minimum of two detention times (6 hours). Preliminary results for caffeine show that removals were minimal in both the bench and pilot scale systems when ozonation was not included in the treatment train. However, almost complete removal (95%) was observed when ozonation was used. For estradiol, removals of 7 to 12% were observed in bench-scale experiments without ozone while in the pilot plant 100% removal of the compound after coagulation and flocculation. This suggests sorption may be a significant removal process for more hydrophobic compounds and that floc characteristics may be important in assessing this removal.
Key words: drinking water treatment, pharmaceuticals, unit processes