Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this would lead to: (i) improvement of the ecological integrity, (ii) reduction of biodiversity loss, and (iii) faster achievement of objectives of legislative requirements, e.g., the European Water Framework Directive

Adaption von Auftragsvergabestrategien in der Referenzfallstudie Produktionstechnik

Available from TIB Hannover: RR 4485(2001,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Investigation of convergence rates in risk theory in presence of heavy tails

Limit theorems for various random variables occurring in risk theory have been established in [6]. Based on a theorem for the variable Z"("u"), normalized with a function a(u), rates of convergence are calculated in this paper. For some special cases the function a(u) was determined in such a manner that this rate could be increased. The proofs include developments occurring terms into sequences. (orig.)Available from TIB Hannover: RR 4487(1996,24) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

InnoRegio Mahreg. M-Tr rate at de-Center - Personalisierte Kommunikationsplattform fuer das geschaeftsvorgangsbasierte Transaktionsmanagement mobiler Dienste im Automobilbereich Schlussbericht

Available from TIB Hannover: F03B1056 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany); Forschungszentrum Juelich GmbH (Germany)DEGerman

Innovative Loesungen zum Montageschweissen in verschiedenen Schweisspositionen

SIGLEAvailable from TIB Hannover: RR 4487(1997,1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekKultusministerium des Landes Sachsen-Anhalt, Magdeburg (Germany)DEGerman

Anwendungskonzepte fuer die rechnerunterstuetzte integrierte Produktion. Entwicklung und Transfer fuer die personelle, organisatorische und technische Gestaltung eines Bereiches der auftragsgebundenen Einzel- und Kleinserienfertigung eines Dieselmotorenherstellers auf dem Gebiet der ehemaligen DDR Schlussbericht

SIGLEAvailable from TIB Hannover: F95B926+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Statistics of an alternating repair model

In this paper the alternating repair model is introduced. For determining the model parameters the maximum likelihood estimator is considered. The distribution of the life times after perfect repairs and imperfect repairs are obtained by using Pareto, Log-linear and Weibull-type intensities. (orig.)SIGLEAvailable from TIB Hannover: RR 4487(1997,28) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman