Sludge Watch ==> Study: Wastewater pharmaceuticals impact microbes in aquatic environment

[Maureen Reilly]

ASAP Environ. Sci. Technol., ASAP Article, 10.1021/es072026x
Web Release Date: January 19, 2008
Copyright © 2008 American Chemical Society


Effects of Pharmaceutically Active Compounds on a Mixed Microbial Community 
Originating from a Municipal Wastewater Treatment Plant

Shuyi Wang, Ryan M. Holzem,† and Claudia K. Gunsch*
Department of Civil and Environmental Engineering, Duke University, Box 
90287, Durham, North Carolina 27708

Received for review August 14, 2007
Revised manuscript received December 9, 2007
Accepted December 10, 2007


Abstract:
The growth and composition of microorganisms found in a municipal wastewater 
treatment plant were investigated in the presence of four pharmaceutically 
active compounds (PhACs) [ketoprofen, naproxen, carbamazepine, and clofibric 
acid] in batch reactors at varying organic loadings. Overall, the data 
suggest that microbial growth inhibition was correlated to organic loading 
rather than PhAC concentration.

Significant inhibition ranging from 34 to 43% was observed under the lowest 
organic loading for all PhACs other than clofibric acid. No inhibition was 
observed at the highest organic loading. Higher microbial inhibition was not 
observed with increased PhAC concentration for a given organic loading. 
These results indicate that the presence of PhAC may affect microbial growth 
especially under lower organic loading conditions. Further validation is 
required with additional PhACs, organic substrates, and a wider loading 
range.

In addition, significant microbial shifts were observed in the presence of 
ketoprofen and naproxen. These data suggest that, in addition to their 
effect on overall microbial growth, PhACs may affect the microbial ecology 
and additional research should be carried out to identify PhACs that have 
the potential of affecting ecologically important microorganisms in 
wastewater treatment processes and aquatic environments in general.