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Bewertung von Transformationsprodukten bei der Trinkwasseraufbereitung
(2014)
Oxidative Transformationsprodukte von Spurenstoffen werden am Fallbeispiel PSM-Metaboliten auf ihr toxisches Potenzial untersucht. Im Labormaßstab werden Ozonung, Anreicherung und (gen)toxikologische Testung miteinander gekoppelt.
© Energie Wasser Praxis
Abwasserdesinfektion
(2015)
In dem F&E-Projekt "Abwasserdesinfektion" der Berliner Wasserbetriebe und des Umweltbundesamts wurden vier Desinfektionsverfahren für den Ablauf des Klärwerks Ruhleben auf ihre Effektivität getestet. Diese zeigen gegenüber den Indikatorbakterien E. coli und intestinale Enterokokken eine gute Desinfektionswirkung. Für die Elimination der besonders desinfektionsmittelresistenten Parasitendauerstadien erwies sich nur die Behandlung mit der Kombination Mikrosieb plus UV-Bestrahlung als durchgehend effektiv. Teilweise wurde auch mit Ozon eine Reduktion durch die Behandlung erreicht. Die chemische Desinfektion mit Perameisensäure konnte weder für die Viren noch für die Parasitendauerstadien eine ausreichende Reduktion bewirken. Die drei anderen Verfahren zeigten sich hinsichtlich der Elimination von Phagen/Viren prinzipiell geeignet, wobei mit der Ozonung tendenziell die beste Reduktion erreicht wurde. Allerdings muss durch weitere Versuche eine Optimierung erfolgen, da sich die Ergebnisse bei den Behandlungen an den einzelnen Versuchstagen teilweise stark unterschieden. Aufgrund der wenigen untersuchten Proben für humanpathogene Viren sind diese Ergebnisse nur für eine erste Orientierung geeignet. Quelle: http://www.dwa.de
The challenge in preparing particle suspensions for aquatic microplastic research
(2019) Eitzen, Lars; Paul, Sophia; Braun, Ulrike; Ruhl, Aki Sebastian
The occurrence of small particles consisting of organic polymers, so-called microplastic (MP), in aquatic environments attracts increasing interest in both public and science. Recent sampling campaigns in surface waters revealed substantial numbers of particles in the size range from a few micrometers to a few millimeters. In order to validate sample preparation, identification and quantification and to investigate the behavior of MP particles and potential toxic effects on organisms, defined MP model particles are needed. Many studies use spherical compounds that probably behave differently compared to irregularly shaped MP found in environmental samples. However, preparation and handling of MP particles are challenging tasks and have been systematically investigated in the present study. Polystyrene (PS) as a commonly found polymer with a density slightly above that of water was selected as polymer type for milling and fractionation studies. A cryogenic ball mill proved to be practical and effective to produce particles in the size range from 1 to 200â€¯Ìm. The yield of small particles increased with increasing pre-cooling and milling durations. Depending on the concentration and the size, PS particles do not completely disperse in water and particles partly creep vertically up along glass walls. Stabilized MP suspensions without use of surfactants that might harm organisms are needed for toxicological studies. The stabilization of PS particle suspensions with ozone treatment reduced the wall effect and increased the number of dispersed PS particles but increased the dissolved organic carbon concentration and changed the size distribution of the particles. © 2018 Elsevier Inc. All rights reserved.
Assessing the protection gap for mobile and persistent chemicals during advanced water treatment - a study in a drinking water production and wastewater treatment plant
(2022) Gollong, Grete; Neuwald, Isabelle; Junek, Ralf; Kuckelkorn, Jochen
Persistent and mobile (PM) chemicals spread quickly in the water cycle and can reach drinking water. If these chemicals are also toxic (PMT) they may pose a threat to the aquatic environment and drinking water alike, and thus measures to prevent their spread are necessary. In this study, nontarget screening and cell-based toxicity tests after a polarity-based fractionation into polar and non-polar chemicals are utilized to assess and compare the effectiveness of ozonation and filtration through activated carbon in a wastewater treatment and drinking water production plant. Especially during wastewater treatment, differences in removal efficiency were evident. While median areas of non-polar features were reduced by a factor of 270, median areas for polar chemicals were only reduced by a factor of 4. Polar features showed significantly higher areas than their non-polar counterparts in wastewater treatment plant effluent and finished drinking water, implying a protection gap for these chemicals. Toxicity tests revealed higher initial toxicities (especially oxidative stress and estrogenic activity) for the non-polar fraction, but also showed a more pronounced decrease during treatment. Generally, the toxicity of the effluent was low for both fractions. Combined, these results imply a less effective removal but also a lower toxicity of polar chemicals. The behaviour of features during advanced waste and drinking water treatment was used to classify them as either PM chemicals or mobile transformation products (M-TPs). A suspect screening of the 476 highest intensity PM chemicals and M-TPs in 57 environmental and tap water samples showed high frequencies of detection (median >80%), which indicates the wide distribution of these chemicals in the aquatic environment and thus supports the chosen classification approach and the more generally applicability of obtained insights. © 2022 Elsevier

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