Abteilung Umwelttoxikologie

Weiterentwickelte Oxidationsprozesse

Behandelbarkeit von Wasser durch Oxidationsprozesse – Testverfahren zur toxikologischen Beurteilung

Eine Reihe technischer und natürlicher Prozesse führt zur Transformation von Chemikalien in der aquatischen Umwelt. Dazu gehören die Ozonung und die Bestrahlung mit ultraviolettem Licht. Selbst anderweitig stabile Chemikalien können so zum Beispiel aus Trink- oder Abwasser entfernt werden. Doch ist die Transformation der Chemikalien auch gleichzusetzen mit einem reduzierten Umweltrisiko? Basierend auf einer engen Verknüpfung von Verständnis über chemische Transformationsprozesse, chemischer Analytik und Bioassays entwickeln wir Strategien, um dieser Frage nachzugehen. Dabei steht der sogenannte effektorientierte Prüfansatz im Mittelpunkt. 

Der effektorientierte Prüfansatz basiert auf dem toxischen Potenzial der Ausgangssubstanz und der durch Transformationsprozesse entstehenden Mischungen in biologischen Wirkungstests. Nimmt das toxische Potenzial der Substanzmischungen im Verlauf der Transformationsprozesse proportional zum Verlust der Ausgangssubstanz ab, kann man davon ausgehen, dass die Ausgangssubstanz die Toxizität dominiert und damit entscheidend für die Umweltrisikobewertung ist. Nur wenn die Mischung aus Transformationsprodukten toxischer ist als von der Ausgangssubstanz erwartet, sind weitere Schritte zur Identifizierung der toxikologisch aktiven Substanz(en) gefragt. Dazu gehört zum Beispiel eine Kombination aus Fraktionierung sowie biologischer und chemischer Analytik. Das effektorientierte Prüfverfahren lässt sich in vier Schritte unterteilen (Abb. 1). Wir haben es bisher auf eine Reihe von verschiedenen chemischen Substanzklassen und biologische Wirkungen in definierten Medien oder komplexen Matrizes getestet.

Publikationen

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   0 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=14624, pid=124)
      originalId => protected14624 (integer)
      authors => protected'Linden, K. G.; Parker, A. M.; Rosario-Ortiz, F.; vo
         n Gunten, U.; Mestankova, H.; Canonica, S.; Schirmer, K.
         ; Cotton, C.; Collins, J.; Elovitz, M.; Swaim, P.
' (221 chars) title => protected'Advanced oxidation and transformation of organic contaminants' (61 chars) journal => protected'' (0 chars) year => protected2015 (integer) volume => protected0 (integer) issue => protected'' (0 chars) startpage => protected'130&nbsp;p' (10 chars) otherpage => protected'' (0 chars) categories => protected'' (0 chars) description => protected'<em>Objectives</em><br />The goal of the project was to evaluate the treatme
         nt of a representative list of organic contaminants from the Contaminant Can
         didate List 3 (CCL 3) via UV- and ozone-based advanced oxidation processes (
         AOPs). The research focused on these chemicals because they are being explor
         ed for possible regulation by the EPA in the future. The specific objectives
          of the research were to:<br />1. Select and prioritize CCL<sub>3</sub> cont
         aminants for investigation<br />2. Select bioassays used to evaluate biologi
         cal activity<br />3. Apply advanced oxidation treatment of CCL<sub>3</sub> c
         hemicals using UV-H<sub>2</sub>O<sub>2</sub> and O<sub>3</sub>/O<sub>3</sub>
         -H<sub>2</sub>O<sub>2</sub> processes<br />4. Monitor AOP treatment using bi
         oassay testing<br />5. Engineer evaluation for AOP operating conditions that
          minimize post-treatment bioactivity [...]
' (878 chars) serialnumber => protected'' (0 chars) doi => protected'' (0 chars) uid => protected14624 (integer) _localizedUid => protected14624 (integer)modified _languageUid => protectedNULL _versionedUid => protected14624 (integer)modified pid => protected124 (integer)
1 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=8127, pid=124) originalId => protected8127 (integer) authors => protected'Schindler Wildhaber,&nbsp;Y.; Mestankova,&nbsp;H.; Schärer,&nbsp;M.; Schirm
         er,&nbsp;K.; Salhi,&nbsp;E.; von Gunten,&nbsp;U.
' (124 chars) title => protected'Novel test procedure to evaluate the treatability of wastewater with ozone' (74 chars) journal => protected'Water Research' (14 chars) year => protected2015 (integer) volume => protected75 (integer) issue => protected'' (0 chars) startpage => protected'324' (3 chars) otherpage => protected'335' (3 chars) categories => protected'micropollutant oxidation; oxidation by-products; bioassays; effluent toxicit
         y; ozonation; transformation products
' (113 chars) description => protected'Organic micropollutants such as pharmaceuticals, estrogens or pesticides ent
         er the environment continuously through the effluent of municipal wastewater
          treatment plants (WWTPs). Enhanced treatment of wastewater (WW) by ozone (O
         <SUB>3</SUB>) is probably one of the simplest measures for abatement of orga
         nic micropollutants to avoid their discharge to the aquatic environment. Dur
         ing ozonation most organic micropollutants present in treated WW are oxidize
         d either by a direct reaction with O<SUB>3</SUB> or by secondarily formed hy
         droxyl radicals (<B>·</B>OH). However, undesired oxidation by-products from
          the oxidative transformation of matrix components can also be formed. A mod
         ular laboratory decision tool based on the findings of previous investigatio
         ns is presented to test the feasibility of ozonation as an option to upgrade
          specific WWTPs. These modules consist of investigations to assess (i) the m
         atrix effects on ozone stability, (ii) the efficiency of micropollutant remo
         val, (iii) the oxidation by-product formation, as well as (iv) bioassays to
         measure specific and unspecific toxicity of the treated WWs.<BR/>Matrix effe
         cts on ozone stability (quantified as O<SUB>3</SUB> and <B>·</B>OH exposure
         s) can give first indications on the suitability of an ozonation step. Ozona
         tion of WWs yielding O<SUB>3</SUB> and <B>·</B>OH exposures and micropollut
         ant abatement similar to reference values evoked a significant improvement o
         f the water quality as indicated by a broad range of bioassays. Irregular be
         havior of the ozonation points towards unknown compounds, possibly leading t
         o the formation of undesired degradation products. It has been observed that
          in such WWs ozonation partly enhanced toxicity. In summary, the presented t
         iered laboratory test procedure represents a relatively cheap and straight-f
         orward methodology to evaluate the feasibility of ozonation to upgrade speci
         fic WWTPs for micropollutant removal based on chemical and biological measur
         ements.
' (1983 chars) serialnumber => protected'0043-1354' (9 chars) doi => protected'10.1016/j.watres.2015.02.030' (28 chars) uid => protected8127 (integer) _localizedUid => protected8127 (integer)modified _languageUid => protectedNULL _versionedUid => protected8127 (integer)modified pid => protected124 (integer)
2 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=8177, pid=124) originalId => protected8177 (integer) authors => protected'Wunderlin,&nbsp;P.; Mestankova,&nbsp;H.; Salhi,&nbsp;E.; Schindler Wildhaber
         ,&nbsp;Y.; Schärer,&nbsp;M.; Schirmer,&nbsp;K.; von Gunten,&nbsp;U.
' (144 chars) title => protected'Behandelbarkeit von Abwasser mit Ozon. Testverfahren zur Beurteilung' (68 chars) journal => protected'Aqua & Gas' (10 chars) year => protected2015 (integer) volume => protected95 (integer) issue => protected'7-8' (3 chars) startpage => protected'28' (2 chars) otherpage => protected'38' (2 chars) categories => protected'' (0 chars) description => protected'Eine Ozonung als zusätzliche Reinigungsstufe auf einer kommunalen Abwasserr
         einigungsanlage (ARA) bewirkt eine deutliche Abnahme der Mikroverunreinigung
         en. Bei speziellen Belastungen, z.B. aufgrund bedeutender Industrie- oder Ge
         werbeabwassereinleitungen, können durch die Ozonung jedoch neue Stoffe, sog
         enannte Transformationsprodukte, gebildet werden. Daher soll künftig im Ein
         zelfall ein Testverfahren aus fünf Modulen prüfen, ob sich ein bestimmtes
         Abwasser für eine Ozonbehandlung eignet oder nicht.
' (508 chars) serialnumber => protected'2235-5197' (9 chars) doi => protected'' (0 chars) uid => protected8177 (integer) _localizedUid => protected8177 (integer)modified _languageUid => protectedNULL _versionedUid => protected8177 (integer)modified pid => protected124 (integer)
3 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=7752, pid=124) originalId => protected7752 (integer) authors => protected'Mestankova,&nbsp;H.; Schirmer,&nbsp;K.; Canonica,&nbsp;S.; von Gunten,&nbsp;
         U.
' (78 chars) title => protected'Development of mutagenicity during degradation of <I>N</I>-nitrosamines by a
         dvanced oxidation processes
' (103 chars) journal => protected'Water Research' (14 chars) year => protected2014 (integer) volume => protected66 (integer) issue => protected'' (0 chars) startpage => protected'399' (3 chars) otherpage => protected'410' (3 chars) categories => protected'N-nitrosamines; hydroxyl radicals; ozone; UV photolysis; mutagenicity; Ames
         test
' (80 chars) description => protected'Development of mutagenicity of five <I>N</I>-nitrosamines (<I>N</I>-nitrosod
         imethylamine (NDMA), <I>N</I>-nitrosodiethylamine (NDEA), <I>N</I>-nitrosodi
         -n-propylamine (NDPA), <I>N</I>-nitrosopyrrolidine (NPYR) and <I>N</I>-nitro
         sodiphenylamine (NDPhA)) was investigated during oxidative processes involvi
         ng UV-photolysis, ozone and <B>·</B>OH radicals. The mutagenicity was detec
         ted by the Ames test with 3 different strains, TA98, TAMix and YG7108, a str
         ain which is sensitive for <I>N</I>-nitrosamines, in presence and absence of
          metabolic activation (S9). UV photolysis of mutagenic <I>N</I>-nitrosamines
          (NDMA, NDEA, NDPA and NPYR) leads to the removal of their specific mutageni
         c activity as detected in YG7108 in the presence of S9. A formation of mutag
         ens during UV photolysis was detected only in case of NDPhA in the strain TA
         98. Oxidation products of NDMA, NDEA and NDPhA did not show any significant
         mutagenicity in the strains used, whereas oxidation of NDPA and NPYR by hydr
         oxyl radicals seems to lead to the formation of direct mutagens (mutagenic i
         n the absence of S9) in YG7108 and TAMix. Oxidation by hydroxyl radicals of
         <I>N</I>-nitrosamines with chains longer than ethyl can mimic metabolic acti
         vation of <I>N</I>-nitrosamines <I>in vivo</I>.
' (1264 chars) serialnumber => protected'0043-1354' (9 chars) doi => protected'10.1016/j.watres.2014.08.012' (28 chars) uid => protected7752 (integer) _localizedUid => protected7752 (integer)modified _languageUid => protectedNULL _versionedUid => protected7752 (integer)modified pid => protected124 (integer)
4 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=6765, pid=124) originalId => protected6765 (integer) authors => protected'Mestankova,&nbsp;H.; Schirmer,&nbsp;K.; Escher,&nbsp;B.&nbsp;I.; von Gunten,
         &nbsp;U.; Canonica,&nbsp;S.
' (103 chars) title => protected'Removal of the antiviral agent oseltamivir and its biological activity by ox
         idative processes
' (93 chars) journal => protected'Environmental Pollution' (23 chars) year => protected2012 (integer) volume => protected161 (integer) issue => protected'' (0 chars) startpage => protected'30' (2 chars) otherpage => protected'35' (2 chars) categories => protected'Tamiflu; ozone; hydroxyl radical; degradation; neuromainidase inhibitor acti
         vity
' (80 chars) description => protected'The antiviral agent oseltamivir acid (OA, the active metabolite of Tamiflu<S
         UP>®</SUP>) may occur at high concentrations in wastewater during pandemic
         influenza events. To eliminate OA and its antiviral activity from wastewater
         , ozonation and advanced oxidation processes were investigated. For circumne
         utral pH, kinetic measurements yielded second-order rate constants of 1.7 ±
          0.1 × 10<SUP>5</SUP> and 4.7 ± 0.2 × 10<SUP>9</SUP> M<SUP>−1</SUP> s<S
         UP>−1</SUP> for the reaction of OA with ozone and hydroxyl radical, respec
         tively. During the degradation of OA by both oxidants, the antiviral activit
         y of the treated aqueous solutions was measured by inhibition of neuraminida
         se activity of two different viral strains. A transient, moderate (two-fold)
          increase in antiviral activity was observed in solutions treated up to a le
         vel of 50% OA transformation, while for higher degrees of transformation the
          activity corresponded to that caused exclusively by OA. OA was efficiently
         removed by ozonation in a wastewater treatment plant effluent, suggesting th
         at ozonation can be applied to remove OA from wastewater.
' (1121 chars) serialnumber => protected'0269-7491' (9 chars) doi => protected'10.1016/j.envpol.2011.09.018' (28 chars) uid => protected6765 (integer) _localizedUid => protected6765 (integer)modified _languageUid => protectedNULL _versionedUid => protected6765 (integer)modified pid => protected124 (integer)
Linden, K. G.; Parker, A. M.; Rosario-Ortiz, F.; von Gunten, U.; Mestankova, H.; Canonica, S.; Schirmer, K.; Cotton, C.; Collins, J.; Elovitz, M.; Swaim, P. (2015) Advanced oxidation and transformation of organic contaminants, 130 p, Institutional Repository
Schindler Wildhaber, Y.; Mestankova, H.; Schärer, M.; Schirmer, K.; Salhi, E.; von Gunten, U. (2015) Novel test procedure to evaluate the treatability of wastewater with ozone, Water Research, 75, 324-335, doi:10.1016/j.watres.2015.02.030, Institutional Repository
Wunderlin, P.; Mestankova, H.; Salhi, E.; Schindler Wildhaber, Y.; Schärer, M.; Schirmer, K.; von Gunten, U. (2015) Behandelbarkeit von Abwasser mit Ozon. Testverfahren zur Beurteilung, Aqua & Gas, 95(7-8), 28-38, Institutional Repository
Mestankova, H.; Schirmer, K.; Canonica, S.; von Gunten, U. (2014) Development of mutagenicity during degradation of N-nitrosamines by advanced oxidation processes, Water Research, 66, 399-410, doi:10.1016/j.watres.2014.08.012, Institutional Repository
Mestankova, H.; Schirmer, K.; Escher, B. I.; von Gunten, U.; Canonica, S. (2012) Removal of the antiviral agent oseltamivir and its biological activity by oxidative processes, Environmental Pollution, 161, 30-35, doi:10.1016/j.envpol.2011.09.018, Institutional Repository