Sanierungsforschung in regional kontaminierten Aquiferen (SAFIRA) – 2. Projektüberblick und Pilotanlage

The joint research project SAFIRA, which is supported by the Federal Ministry of Science and Education (BMBF), deals with the development of innovative technologies for the in situ remediation of heavily contaminated groundwater at the in situ pilot facility in Bitterfeld. In order to evaluate the new promising technological approaches comprehensively, methodological tools are developed to comparatively address economical, ecological as well as a environmental issues of related remediation scenarios. The design period for innovative technologies can hardly be forecasted and/or its success be guaranteed. To prove a long-term stability as well as to reach a sound economical and ecological evaluation for new approaches an on site operation over extended periods of time is needed. Therefore a variety of technologies are tested and optimized simultaneously, in order to achieve a thorough comparison of technologies at the end of the project.     

Sanierungsforschung in regional kontaminierten Aquiferen (SAFIRA) – 1. Information zum Forschungsschwerpunkt am Standort Bitterfeld

The SAFIRA-project (remediation research in regionally contaminated aquifers) focuses on innovative in situ remediation technologies to treat complex groundwater contamination. For this purpose, a model site located in Bitterfeld, Germany, was selected. The site is heavily contaminated with aliphatic and aromatic chlorinated hydrocarbons. The goal of the project is to develop, test and optimize new technologies of reactive barriers under controlled in situ conditions in a pilot plant. In order to create the necessary basis for this model project, the hydrogeological and hydrogeochemical conditions at the selected field site were investigated and various technologies for the design of the in situ pilot plant were examinated. Small-scale laboratory studies and tests in a mobile test unit (scale 1 m) were carried out in order to test the technologies prior to their application in the field. The technologies now tested in the reactive columns at the pilot plant include physico-chemical, microbial and combined techniques.     

Xenobiotics in groundwater and surface water of the city of Leipzig

Xenobiotics are increasingly being considered as ecotoxicologically relevant for the aquatic environment and human health. Their behaviour and the effects on the environment have not yet been comprehensively investigated and, therefore, are currently the subject of the project WASSER Leipzig initiated by the UFZ. The results of this article are based on groundwater and surface water analyses of a watershed within the town of Leipzig. Here the industrial chemicals bisphenol-A and t-nonylphenol, the polycyclic fragrances galaxolide and tonalide, the antiepileptic drug carbamacepine and caffeine where investigated. Xenobiotics showed ubiquitous occurrence in the rivers, which were contaminated from treated and untreated sewage, as well as in groundwater, contaminated by leaky sewers. Mean concentrations up to several hundred ng/l were found in the rivers, while groundwater concentrations, except for bisphenol-A, tended to be lower. Applying the statistical factor analysis on the hydrochemical measurements, a differentiation of the xenobiotics with regard to their hydrochemical behaviour in groundwater was performed.     

Medical target prediction from genome sequence: combining different sequence analysis algorithms with expert knowledge and input from artificial intelligence approaches.

By exploiting the rapid increase in available sequence data, the definition of medically relevant protein targets has been improved by a combination of: (i) differential genome analysis (target list): and (ii) analysis of individual proteins (target analysis). Fast sequence comparisons, data mining, and genetic algorithms further promote these procedures. Mycobacterium tuberculosis proteins were chosen as applied examples.     

Eine Echtzeit-Online-Methode zur Beurteilung der künstlichen Grundwasseranreicherung und Grundwasserentnahme

Grundwasser - Eine nachhaltige Wasserversorgung in urbanen Gebieten stellt aufgrund des Nutzungsdrucks sowie vielfältiger anthropogener Einträge eine große Herausforderung dar....     

Predicting concentrations of organic chemicals in fish by using toxicokinetic models

Quantification of chemical toxicity continues to be generally based on measured external concentrations. Yet, internal chemical concentrations have been suggested to be a more suitable parameter. To better understand the relationship between the external and internal concentrations of chemicals in fish, and to quantify internal concentrations, we compared three toxicokinetic (TK) models with each other and with literature data of measured concentrations of 39 chemicals. Two one-compartment models, together with the physiologically based toxicokinetic (PBTK) model, in which we improved the treatment of lipids, were used to predict concentrations of organic chemicals in two fish species: rainbow trout (Oncorhynchus mykiss) and fathead minnow (Pimephales promelas). All models predicted the measured internal concentrations in fish within 1 order of magnitude for at least 68% of the chemicals. Furthermore, the PBTK model outperformed the one-compartment models with respect to simulating chemical concentrations in the whole body (at least 88% of internal concentrations were predicted within 1 order of magnitude using the PBTK model). All the models can be used to predict concentrations in different fish species without additional experiments. However, further development of TK models is required for polar, ionizable, and easily biotransformed compounds.     

Predicting adult fish acute lethality with the zebrafish embryo: relevance of test duration, endpoints, compound properties, and exposure concentration analysis

The zebrafish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, which is required by various regulations for environmental risk assessment of chemicals. We investigated the reliability of the embryo test by probing organic industrial chemicals with a wide range of physicochemical properties, toxicities, and modes of toxic action. Moreover, the relevance of using measured versus nominal (intended) exposure concentrations, inclusion of sublethal endpoints, and different exposure durations for the comparability with reported fish acute toxicity was explored. Our results confirm a very strong correlation of zebrafish embryo to fish acute toxicity. When toxicity values were calculated based on measured exposure concentrations, the slope of the type II regression line was 1 and nearly passed through the origin (1 to 1 correlation). Measured concentrations also explained several apparent outliers. Neither prolonged exposure (up to 120 h) nor consideration of sublethal effects led to a reduced number of outliers. Yet, two types of compounds were less lethal to embryos than to adult fish: a neurotoxic compound acting via sodium channels (permethrin) and a compound requiring metabolic activation (allyl alcohol).     

Moving targets, long-lived infrastructure, and increasing needs for integration and adaptation in water management: an illustration from Switzerland

Switzerland provides an example of successful management of water infrastructure and water resources that was accomplished largely without integration across sectors. Limitations in this approach have become apparent; decisions that were formerly based only on technical and economic feasibility must now incorporate broader objectives such as ecological impact. In addition, current and emerging challenges relate to increasingly complex problems that are likely to demand more integrated approaches. If such integration is to be of benefit, it must be possible to redirect resources across sectors, and the synergies derived from integration must outweigh the additional cost of increased complexity.