Transformation, CO2 formation and uptake of four organic micropollutants by carrier-attached microorganisms

Research output: Contribution to journalArticle

Abstract

A tiered process was developed to assess the transformation, CO2 formation and uptake of four organic micropollutants by carrier-attached microorganisms from two municipal wastewater treatment plants. At the first tier, primary transformation of ibuprofen, naproxen, diclofenac, and mecoprop by carrier-attached microorganisms was shown by the dissipation of the target compounds and the formation of five transformation products using LC-tandem MS. At the second tier, the microbial cleavage of the four organic micropollutants was confirmed with 14C-labeled micropollutants through liquid scintillation counting of the 14CO2 formed. At the third tier, microautoradiography coupled with fluorescence in situ hybridization (MAR-FISH) was used to screen carrier-attached microorganisms for uptake of the four radiolabeled micropollutants. Results from the MAR-FISH screening indicated that only a small fraction of the microbial community (≤1‰) was involved in the uptake of the radiolabeled micropollutants and that the responsible microorganisms differed between the compounds. At the fourth tier, the microbial community structure of the carrier-attached biofilms was analyzed by 16S rRNA gene amplicon sequencing. The sequencing results showed that the MAR-FISH screening targeted ∼80% of the microbial community and that several taxonomic families within the FISH-probed populations with MAR-positive signals (i.e. Firmicutes, Gammaproteobacteria, and Deltaproteobacteria) were present in both biofilms. From the broader perspective of organic micropollutant removal in biological wastewater treatment, the MAR-FISH results of this study indicate a high degree of microbial substrate specialization that could explain differences in transformation rates and patterns between micropollutants and microbial communities.

Details

Authors
  • Per Falås
  • Kevin S. Jewell
  • Nina Hermes
  • Arne Wick
  • Thomas A. Ternes
  • Adriano Joss
  • Jeppe Lund Nielsen
Organisations
External organisations
  • Eawag: Swiss Federal Institute of Aquatic Science and Technology
  • Federal Institute of Hydrology
  • Aalborg University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Microbiology

Keywords

  • Biological wastewater treatment, Microautoradiography, Micropollutants, Moving bed biofilm reactors, Transformation
Original languageEnglish
Pages (from-to)405-416
Number of pages12
JournalWater Research
Volume141
Publication statusPublished - 2018 Sep 15
Publication categoryResearch
Peer-reviewedYes