Stormwater retention ponds commonly receive some wastewater through misconnections,
sewer leaks, and sewer overloads, all of which leads to unintended loads of organic
micropollutants, including pharmaceuticals. This study explores the role of pond sediment
in removing pharmaceuticals (naproxen, carbamazepine, sulfamethoxazole, furosemide,
and fenofibrate). It quantifies their sorption potential to the sediments and how
it depends on pH. Then it addresses the degradability of the pharmaceuticals in microcosms
holding sediment beds and pond water. The sediment-water partitioning coefficient
of fenofibrate varied little with pH and was the highest (average log Kd: 4.42 L kg(-1)).
Sulfamethoxazole had the lowest (average log Kd: 0.80 L kg(-1)), varying unsystematically
with pH. The coefficients of naproxen, furosemide and carbamazepine were in between.
The degradation by the sediments was most pronounced for sulfamethoxazole, followed
by naproxen, fenofibrate, furosemide, and carbamazepine. The first three were all
removed from the water phase with half-life of 2-8 days. Over the 38 days the experiment
lasted, they were all degraded to near completion. The latter two were more resistant,
with half-lives between 1 and 2 months. Overall, the study indicated that stormwater
retention ponds have the potential to remove some but not all pharmaceuticals contained
in wastewater contributions.