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This work investigates the influence of ammonium ions and the organic load (chemical oxygen demand (COD)) on the UV/chlorine AOP regarding the maintenance of free available chlorine (FAC) and elimination of 16 emerging contaminants (ECs) from wastewater treatment plant effluent (WWTE) at pilot scale (UV chamber at 0.4 kW). COD inhibited the FAC maintenance in the UV chamber influent at a ratio of 0.16 mg FAC per mg COD (kHOCl&ndash, COD = 182 M&minus, 1s&minus, 1). An increase in ammonium ion concentration led to a stoichiometric decrease of the FAC concentration in the UV chamber influent. Especially in cold seasons due to insufficient nitrification, the ammonium ion concentration in WWTE can become so high that it becomes impossible to achieve sufficiently high FAC concentrations in the UV chamber influent. For all ECs, the elimination effect by the UV/combined Cl2 AOP (UV/CC) was not significantly higher than that by sole UV treatment. Accordingly, the UV/chlorine AOP is very sensitive and loses its effectiveness drastically as soon as there is no FAC but only CC in the UV chamber influent. Therefore, within the electrical energy consumption range tested (0.13&ndash, 1 kWh/m3), a stable EC elimination performance of the UV/chlorine AOP cannot be maintained throughout the year.

Apart from cotton cultivation and the production of dyestuffs and optical brighteners, textile finishing is one of the environmental hotspots. The dominating emission mass stream from textile finishing is wastewater as practically all inorganic and most of the organic (more than 90 %) chemical compounds are discharged with wastewater. Emissions to air, although not negligible, and with solid wastes are of significant lower relevance. In addition, in many parts of the globe, water availability and water scarcity respectively are of increasing concern triggering the need to avoid, reduce or recycle textile wastewater.

SchussenAktiv-a Model Study on the Efficacy in Reducing Anthropogenic Micropollutants by Activated Carbon Filtration in Wastewater Treatment Plants-Exposure and Effect Monitoring Prior to the Startup of the Charcoal Adsorption System at the Wastewater Treatment Plant Langwiese, Association for Wastewater Treatment Mariatal, City of Ravensburg, Germany; International audience; Zusammenfassung Durch den kombinierten Einsatz verschiedener Methoden ist nachweisbar, dass sich Spurenstoffe auf den Gesundheitszustand wasserlebender Organismen und die Integrität aquatischer Le-bensgemeinschaft negativ auswirken. Im Projekt SchussenAktiv konnte die Präsenz von Spurenstoffen mit toxischen (z.B. gento-xischen) und hormonellen (z.B. östrogenartigen) Potentialen so-wie tatsächlichen Wirkungen in Verbindung gebracht werden. Die große Variabilität im Nachweis östrogenartig wirkender Chemi-kalien spiegelt sich auch in der Variabilität der nachgewiesenen östrogenen Wirkpotenziale und Wirkungen bei Fischen und Fisch-nährtieren wider. Die reduzierte Anzahl sensitiver Taxa unterhalb der untersuchten Kläranlage Langwiese (AZV Mariatal, Ravens-burg) an der Schussen spricht dafür, dass sich negative Effekte be-reits auf biozönotischer Ebene manifestiert haben. Ein Zusam-menspiel toxischer und hormoneller Einflüsse auf die Organismen in der Schussen ist hierbei aufgrund der erzielten Resultate wahr-scheinlich. Für die als Referenzgewässer ausgewählte Argen konn-te gezeigt werden, dass die untersuchte Probenahmestelle zwar insgesamt als deutlich weniger belastet gelten kann als die Probe-nahmestellen an der Schussen, dass a ber auch hier Bedarf be-steht, bestimmte Expositionen (z. B.-Sitosterol, Cadmium, Ar-sen, Quecksilber, Zink) und Effekte (z. B. Acetylcholinesterase-hemmung bei Fischen, fehlende Abundanz von Gammariden) ge-nauer zu betrachten um gegebenenfalls ihre Ursachen zu eruieren. Using a combination of different chemical and biological methods the project SchussenAktiv provided evidence that micropollutants negatively influence the health status of aquatic organisms and the integrity of aquatic ecosystems. It was possible to establish plausible connections between the presence of distinct micropol-lutants in the environment, toxic (e.g. genotoxic) or hormonal (e.g. estrogen-like) potentials in effluent or surface water samples , and the respective effects in feral fish. Large variability in the abundance of estrogen-like substances was reflected in the variation of both estrogenic potentials and estrogenic effects in fish and invertebrates. The decreased number of sensitive taxa in the river Schussen downstream the wastewater treatment plant Langwiese revealed evidence for detrimental effects also on the community structure. In general, the results of SchussenAktiv led to the suggestion that both toxic and endocrine-active chemicals interact in influencing organisms abundant in the Schussen river downstream sewage treatment plant. In contrast, the sampling site at the Argen river, chosen as a reference, was found to be clearly less polluted than the investigated sites along the Schussen. Nevertheless , detected pollutants (-sitosterol, cadmium, arsenic, mercury , zinc) and effects (AChE inhibition in fish, absence of gam-marids) call for a causal analysis also in the river Argen.