Abteilung Oberflächengewässer

Resistenzen in der Nachbehandlung von ozoniertem Abwasser


Die Schweiz hat sich 2014 entschieden, große Kläranlagen mit einer zusätzlichen Reinigungsstufe zu modernisieren, um die Freisetzung von Mikroverunreinigungen in die Umwelt zu reduzieren. Um dieses Ziel zu erreichen werden Technologien auf der Basis von Oxidation (Ozonierung) oder Adsorption (Aktivkohle oder Sandfilter) eingesetzt. Es fehlen jedoch Daten über die Freisetzung von Antibiotikaresistenzen nach diesen zusätzlichen Reinigungsverfahren. Daher müssen wir das Verhalten der Antibiotikaresistenz in verschiedenen fortgeschrittenen Behandlungsverfahren untersuchen, um festzustellen ob Antibiotikaresistenzbakterien und damit verbundene Resistenzgene effizient eliminiert oder reduziert werden.
Unser aktuelles Projekt konzentriert sich auf das Schicksal der Antibiotikaresistenz bei der biologischen Nachbehandlung von ozoniertem Abwasser. Wir werden Proben von mindestens 5 Installationen nehmen, die unterschiedliche Situationen hinsichtlich Art (Sandfilter oder Granulierte Aktivkohle) und Alter bzw. Vorgeschichte des Filtermaterials repräsentieren. Wir werden Metagenomik und Q-PCR verwenden, um Veränderungen von Bakterienpopulation und Resistenzgenen beim Durchlaufen der Anlagen zu untersuchen. Durchflusszytometrie und Bakterienkultur werden verwendet, um Zellzahlen und die Prävalenz von resistenten Keimen quantitativ zu erfassen. Das Projekt wird wichtige Daten zum Verhalten der Antibiotikaresistenz während der Ozonung und zum Potential des wideraufwachsens resistenter Bakterien in der Nachbehandlung liefern. Aufgrund der Resultate werden Empfehlungen entwickelt, um einen positiven Effekt der neuen Reinigungsstufen auch auf die Freisetzung von resistenten Bakterien zu ermöglichen.

Publikation

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      originalId => protected14002 (integer)
      authors => protected'Czekalski, N.; Imminger, S.; Salhi, E.; Veljkovic, M.; K
         leffel, K.; Drissner, D.; Hammes, F.; Bürgmann, H.; Von
          Gunten, U.' (168 chars)
      title => protected'Inactivation of antibiotic resistant bacteria and resistance genes by ozone:
          from laboratory experiments to full-scale wastewater treatment' (139 chars)
      journal => protected'Environmental Science and Technology' (36 chars)
      year => protected2016 (integer)
      volume => protected50 (integer)
      issue => protected'21' (2 chars)
      startpage => protected'11862' (5 chars)
      otherpage => protected'11871' (5 chars)
      categories => protected'' (0 chars)
      description => protected'Ozone, a strong oxidant and disinfectant, seems ideal to cope with future ch
         allenges of water treatment, such as micropollutants, multiresistant bacteri
         a (MRB) and even intracellular antibiotic resistance genes (ARG), but inform
         ation on the latter is scarce. In ozonation experiments we simultaneously de
         termined kinetics and dose-dependent inactivation of <I>Escherichia coli</I>
          and its plasmid-encoded sulfonamide resistance gene <I>sul1</I> in differen
         t water matrixes. Effects in <I>E. coli</I> were compared to an autochthonou
         s wastewater community. Furthermore, resistance elimination by ozonation and
          post-treatment were studied in full-scale at a wastewater treatment plant (
         WWTP). Bacterial inactivation (cultivability, membrane damage) and degradati
         on of <I>sul1</I> were investigated using plate counts, flow cytometry and q
         uantitative real-time PCR. In experiments with <I>E. coli</I> and the more o
         zone tolerant wastewater community disruption of intracellular genes was obs
         erved at specific ozone doses feasible for full-scale application, but flocs
          seemed to interfere with this effect. At the WWTP, regrowth during postozon
         ation treatment partly compensated inactivation of MRB, and intracellular <I
         >sul1</I> seemed unaffected by ozonation. Our findings indicate that ozone d
         oses relevant for micropollutant abatement from wastewater do not eliminate 
         intracellular ARG.' (1386 chars)
      serialnumber => protected'0013-936X' (9 chars)
      doi => protected'10.1021/acs.est.6b02640' (23 chars)
      uid => protected14002 (integer)
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Inactivation of antibiotic resistant bacteria and resistance genes by ozone: from laboratory experiments to full-scale wastewater treatment

Ozone, a strong oxidant and disinfectant, seems ideal to cope with future challenges of water treatment, such as micropollutants, multiresistant bacteria (MRB) and even intracellular antibiotic resistance genes (ARG), but information on the latter is scarce. In ozonation experiments we simultaneously determined kinetics and dose-dependent inactivation of Escherichia coli and its plasmid-encoded sulfonamide resistance gene sul1 in different water matrixes. Effects in E. coli were compared to an autochthonous wastewater community. Furthermore, resistance elimination by ozonation and post-treatment were studied in full-scale at a wastewater treatment plant (WWTP). Bacterial inactivation (cultivability, membrane damage) and degradation of sul1 were investigated using plate counts, flow cytometry and quantitative real-time PCR. In experiments with E. coli and the more ozone tolerant wastewater community disruption of intracellular genes was observed at specific ozone doses feasible for full-scale application, but flocs seemed to interfere with this effect. At the WWTP, regrowth during postozonation treatment partly compensated inactivation of MRB, and intracellular sul1 seemed unaffected by ozonation. Our findings indicate that ozone doses relevant for micropollutant abatement from wastewater do not eliminate intracellular ARG.
Czekalski, N.; Imminger, S.; Salhi, E.; Veljkovic, M.; Kleffel, K.; Drissner, D.; Hammes, F.; Bürgmann, H.; Von Gunten, U. (2016) Inactivation of antibiotic resistant bacteria and resistance genes by ozone: from laboratory experiments to full-scale wastewater treatment, Environmental Science and Technology, 50(21), 11862-11871, doi:10.1021/acs.est.6b02640, Institutional Repository