Title of article :
Influence of pharmaceutical residues on the structure of activated sludge bacterial communities in wastewater treatment bioreactors
Author/Authors :
Barbara Kraigher، نويسنده , , Tina Kosjek، نويسنده , , Ester Heath، نويسنده , , Boris Kompare، نويسنده , , Ines Mandic-Mulec، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
11
From page :
4578
To page :
4588
Abstract :
Concern is growing over contamination of the environment with pharmaceuticals because of their widespread use and incomplete removal during wastewater treatment, where microorganisms drive the key processes. The influence of pharmaceuticals on bacterial community structure in activated sludge was assessed in small-scale wastewater treatment bioreactors containing different concentrations (5, 50, 200 and 500 μg L−1) of several commonly used pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac and clofibric acid). T-RFLP analyses of the bacterial 16S rRNA genes indicated a minor but consistent shift in the bacterial community structure in the bioreactor R50 supplied with pharmaceuticals at a concentration of 50 μg L−1, compared to the control reactor R0, which was operated without addition of pharmaceuticals. In the reactors operated with higher concentrations of pharmaceuticals, a greater structural divergence was observed. Bacterial community composition was further investigated by preparation of two clone libraries of bacterial 16S rRNA genes from reactors R0 and R50. Most clones in both libraries belonged to the Betaproteobacteria, among which Thauera, Sphaerotilus, Ideonella and Acidovorax-related spp. dominated. Nitrite-oxidizing bacteria of the genus Nitrospira sp., which are key organisms for the second stage of nitrification in wastewater treatment plants, were found only in the clone library of the reactor without pharmaceuticals. In addition, diversity indices were calculated for the two clone libraries, indicating a reduced diversity of activated sludge bacterial community in the reactor supplied with 50 μg L−1 of each of selected pharmaceuticals.
Keywords :
Activated sludgePharmaceuticalsBacterial community structureT-RFLP16S rRNADiversity
Journal title :
Water Research
Serial Year :
2008
Journal title :
Water Research
Record number :
765131
Link To Document :
بازگشت