This case study deals with long-term contamination of the Leuna aquifer, which is intended to be restored using sustainable technologies financed by the state. The contamination can only be solved using active rather than passive intervention, because the aquifer has an extraordinarily low natural attenuation capacity for the specific pollutants. Due to the longevity of the contamination source, the groundwater treatment technology that was chosen for the site must operate for a minimum of 20 years but probably much longer. Since the polluter-pay principle cannot be applied, the estimated dynamic primary remediation costs must be accepted as a political or social cost, which must be paid by current and future generations.

In many animals, sexual selection on male traits results from female mate choice decisions made during a sequence of courtship behaviors. We use a bower-building cichlid fish, <I>Nyassachromis</I> cf. <I>microcephalus</I>, to show how applying standard selection analysis to data on sequential female assessment provides new insights into sexual selection by mate choice. We first show that the cumulative selection differentials confirm previous results suggesting female choice favors males holding large volcano-shaped sand bowers. The sequential assessment analysis reveals these cumulative differentials are the result of selection acting on different bower dimensions during the courtship sequence; females choose to follow males courting from tall bowers, but choose to engage in premating circling with males holding bowers with large diameter platforms. The approach we present extends standard selection analysis by partitioning the variances of increasingly accurate estimates of male reproductive fitness and is applicable to systems in which sequential female assessment drives sexual selection on male traits.

A major goal of evolutionary biology is to unravel the molecular genetic mechanisms that underlie functional diversification and adaptation. We investigated how changes in gene regulation and coding sequence contribute to sensory diversification in two replicate radiations of cichlid fishes. In the clear waters of Lake Malawi, differential opsin expression generates diverse visual systems, with sensitivities extending from the ultraviolet to the red regions of the spectrum. These sensitivities fall into three distinct clusters and are correlated with foraging habits. In the turbid waters of Lake Victoria, visual sensitivity is constrained to longer wavelengths, and opsin expression is correlated with ambient light. In addition to regulatory changes, we found that the opsins coding for the shortest- and longest-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model of sensory evolution in which both molecular genetic mechanisms work in concert. Changes in gene expression generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes in coding sequence appear to fine-tune visual pigment sensitivity at the short- and long-wavelength ends of this range, where differential opsin expression can no longer extend visual pigment sensitivity.

Background: Transgressive segregation describes the occurrence of novel phenotypes in hybrids with extreme trait values not observed in either parental species. A previously experimentally untested prediction is that the amount of transgression increases with the genetic distance between hybridizing species. This follows from QTL studies suggesting that transgression is most commonly due to complementary gene action or epistasis, which become more frequent at larger genetic distances. This is because the number of QTLs fixed for alleles with opposing signs in different species should increase with time since speciation provided that speciation is not driven by disruptive selection. We measured the amount of transgression occurring in hybrids of cichlid fish bred from species pairs with gradually increasing genetic distances and varying phenotypic similarity. Transgression in multi-trait shape phenotypes was quantified using landmark-based geometric morphometric methods.<BR/>Results: We found that genetic distance explained 52% and 78% of the variation in transgression frequency in F1 and F2 hybrids, respectively. Confirming theoretical predictions, transgression when measured in F2 hybrids, increased linearly with genetic distance between hybridizing species. Phenotypic similarity of species on the other hand was not related to the amount of transgression.<BR/>Conclusion: The commonness and ease with which novel phenotypes are produced in cichlid hybrids between unrelated species has important implications for the interaction of hybridization with adaptation and speciation. Hybridization may generate new genotypes with adaptive potential that did not reside as standing genetic variation in either parental population, potentially enhancing a population's responsiveness to selection. Our results make it conceivable that hybridization contributed to the rapid rates of phenotypic evolution in the large and rapid adaptive radiations of haplochromine cichlids.

Background: Conflicts of interest between the sexes are increasingly recognized as an engine driving the (co-)evolution of reproductive traits. The reproductive behaviour of <I>Drosophila montana</I> suggests the occurrence of sexual conflict over the duration of copulation. During the last stages of copulation, females vigorously attempt to dislodge the mounting male, while males struggle to maintain genital contact and often successfully extend copulations far beyond the females' preferred duration.<BR/>Results: By preventing female resistance, we show that females make a substantial contribution towards shortening copulations. We staged matings under different sex ratio conditions, and provide evidence that copulation duration is a form of male reproductive investment that responds to the perceived intensity of sperm competition as predicted by game theoretical models. Further, we investigated potential benefits to persistent males, and costs to females coerced into longer matings. While males did not benefit in terms of increased progeny production by protracting copulation, female remating was delayed after long first copulations.<BR/>Conclusion: Copulation time is a trait subject to sexual conflict. Mating durations exceeding female optima serve males as a form of 'extended mate guarding': by inducing mating refractoriness in the female, a male extends the time over which its sperm is exclusively used to sire progeny and reduces the likelihood of the female being reinseminated by a competitor.

<I>Background and objectives</I> There is an urgent need to detect, assess, and reduce effects of hormonally active compounds and endocrine disrupters in aquatic systems, as reflected in national research programs like the Swiss NRP 50 "Endocrine Disruptors" and its consensus platforms. As a medium-term measure, the EU strategy on endocrine disruptors (SEC(2007)1635) uses the Endocrine Disruptor Testing and Assessment (EDTA) Task Force of the Organisation for Economic Co-operation and Development (OECD) along with other research activities. In particular the test methods of the OECD that are currently in validation or already validated may contribute to a better understanding of the extent of endocrine disruption, in particular if they are applied on environmental samples and in the context of risk-assessment strategies, for instance in waste water treatment. This article aims to give an overview and an evaluation on available and validated biological test systems for the detection of endocrine disruptive and reproductive effects in aquatic systems. Based on this a recommendation for a modular ecotoxicological test platform is given. The study focuses on test methods for sex hormone active substances.<BR/><I>Material and methods</I> On the basis of an extensive literature search and ongoing international validation efforts by the OECD for methods to detect endocrine disruptive effects, 15 biological test methods (5 <I>in vivo</I> and 10 <I>in vitro</I>) were selected. Comprising, for example, of eight OECD methods and three out of five <I>in-vitro</I> methods mentioned in the Global Water Research Coalition (GWRC) report "Tools to detect estrogenic activity in environmental waters" (Leusch 2008). Experienced users and developers were then asked to rate the test according to given relevant criteria. The resulting criteria profiles were compiled, compared, and evaluated.<BR/><I>Results</I> The methods were selected on the basis of validation status, distribution, their suitability for standardisation, and their proven sensitivity for environmental samples. We assumed that specific YES/YAS-procedures and the ER/AR Calux systems achieve the mentioned criteria. In the case that strong cytotoxicity of environmental samples affects the applicability of cellular reporter gene assays, alternatively a molecular receptor binding assay (e. g. ELRA) could be used. Additional molecular receptor binding assays are currently in validation by the OECD. Modulating effects on steroidgenesis and probably even on aromatase activity can be detected by the OECD validated H295R Steroidgenesis Assay. Its applicability for environmental samples is currently tested. As <I>in-vivo</I> methods different fish assays (e. g. Fish Screening Assay and the Zebrafish Embryo Test) were evaluated. For the detection of effects on the thyroid-associated hormone system the Amphibian Metamorphosis Assay (XEMA, for Xenopus Metamorphosis Assay) will soon be available as an OECD-Guideline. Because of trends in the international community to avoid tests with vertebrates in the future, only an optional recommendation was given for such tests. Reproduction toxicity, on the other hand, can be sensitively tested by the tests using the gastropod <I>Potamopyrgus antipodarum</I>, which, as invertebrate tests, do not require a permit to perform animal testing procedures . This test is also sensitive for many substances which are able to induce an endocrine disruption in vertebrates. Its validation is currently performed by the OECD. The applicability of the herein proposed test methods of the modular test platform for environmental-sample assessments were previously confirmed by several published scientific studies.<BR/><I>Discussion</I> We propose several test methods to be included in an application-oriented modular test platform. These tests should be suitable to efficiently indicate different mechanisms of endocrine disruption and reproduction toxicity, and may be employed in different situations according to their respective advantages. The modular test platform is able to detect impacts on the reproduction relevant effects in invertebrates, amphibians, and fishes. Furthermore the different mode of actions of estrogenic and androgenic receptor binding, steroid genesis and perhaps even the modulation of aromatase are detectable. A research report on the relevance of endocrine substances and pharmaceuticals in aquatic environments (Moltmann et al. 2007) showed that endocrine end-points of <I>in-vivo</I> tests (31 of 71 tested substances) tend to be more sensitive than general ecotoxicological end-points, such as mortality and growth. Consequently, endocrine and general-toxic effects should be detected in an integrative manner by ecotoxicological test platforms.<BR/><I>Conclusions</I> By combining literature research with a targeted query for information about the chosen test procedures it was possible to obtain a detailed overview about the current state-of-the-art of science and technology in the detection of hormone-active effects and reproduction toxicity. Ecotoxicological and regulative aspects were considered equally, and the applicability of the test procedures was evaluated. Because of the diversity of endocrine disrupting mechanisms, a modular combination of <I>in-vivo</I> and <I>in-vitro</I> methods in a joint test platform is needed to recognise and differentiate the transitions from hormone-active effects to endocrine disruption.<BR/><I>Recommendations and perspectives</I> Our study leads to a proposal of a modular ecotoxicological test platform, which offers an integrative detection of hormone-active and reproduction-relevant effects in the aquatic environment. The modular system presented here allows the switching between test modules according to the continuously developing state-of-the-art of science and technology as well as the incorporation of novel developments. Further standardisation of such methods for regulative applications is recommended.

We present a geological map, profiles and the results of a detailed structural analysis of the Early Oligocene Engi Slates southwest of the village of Engi in the Sernft Valley in canton Glarus (Switzerland). In this area, the Engi Slates are folded on a deca- to hectometer scale into tight NW-vergent folds with sharp hinges. This took place during the Plattenberg F<SUB>1</SUB> folding phase. No axial plane foliation was formed. The F<SUB>1</SUB> folds are unconformably cut-off by a 16-25° NE dipping thrust, along which Eocene marls were emplaced onto the folded Engi Slates. We refer to this thrust as Riedboden Thrust and correlate it with the base of the upper, chaotic part of the Wildflysch Nappe of Oberholzer (1942). This is a (probably tectonic) mélange of rocks from the underlying Sardona, Blattengrat and North Helvetic Flysch Units. It lies as a 5 to 100 m thick, more or less continuous nappe below the Glarus Thrust. A younger, SE-dipping tectonic foliation (Plattenberg F<SUB>2</SUB> foliation) cuts both through the folded Engi Slates, the Riedboden Thrust and the Eocene marls. This foliation is the axial plane foliation to meter-scale open F<SUB>2</SUB> folds. It developed parallel to the overturned limbs of the F<SUB>1</SUB>-folds.

The potential for reducing diarrhoea morbidity and improving the health status of children in developing countries using solar water disinfection (SODIS) has been demonstrated in past research. A baseline survey was conducted to explore the feasibility and necessity of introducing SODIS in peri-urban communities of Zimbabwe. The survey sought to establish drinking water quality in these areas and to determine the health and hygiene beliefs as well as practices related to water handling in the household. Microbiological water quality tests and personal interviews were carried out in Epworth township and Hopley farm, two peri-urban areas near the capital of Zimbabwe, Harare. These two areas are among the poorest settlements around Harare with 80% of inhabitants being informal settlers. Community meetings were held to introduce solar water disinfection prior to the survey. This was followed by administration of questionnaires, which aimed to investigate whether the community had ever heard about SODIS, whether they were practicing it, other means that were being used to treat drinking water as well as health and hygiene beliefs and practices. It was found out that most households cannot afford basic water treatment like boiling as firewood is expensive. People generally reported that the water was not palatable due to objectionable odour and taste. Microbiological water quality tests proved that drinking water was contaminated in both areas, which makes the water unsafe for drinking and shows the necessity of treatment. Although the majority of people interviewed had not heard of SODIS prior to the interview, attitudes towards its introduction were very positive and the intention to do SODIS in the future was high. Amongst the ones who had heard about SODIS before the study, usage was high. Plastic PET bottles, which were used for the SODIS experiments are currently unavailable and this has been identified as a potential hindrance to the successful implementation of SODIS.

<I>Background</I> The November 1, 1986 fire at a Sandoz Ltd. storehouse at Schweizerhalle, an industrial area near Basel, Switzerland, resulted in chemical contamination of the environment. The storehouse, which was completely destroyed by the fire, contained pesticides, solvents, dyes, and various raw and intermediate materials. The majority of the approximately 1,250 t of stored chemicals was destroyed in the fire, but large quantities were introduced into the atmosphere, into the Rhine River through runoff of the fire-fighting water, and into the soil and groundwater at the site. The chemicals discharged into the Rhine caused massive kills of benthic organisms and fish, particularly eels and salmonids. Public and private reaction to the fire and subsequent chemical spill was very strong. This happened only a few months after the Chernobyl accident and it destroyed the myth of immunity of Switzerland regarding such catastrophes.<BR/><I>Aim</I> This article reviews the damaging events of November 1986 and aims at striking stock two decades later.<BR/><I>Results and discussion</I> In the aftermath of this once-per-century accident, the aim was to obtain new knowledge for the environmental sciences and to achieve progress for water pollution control issues. The following themes are discussed: mitigation measures by the chemical industry and by the governmental authorities, activities of environmental protection organizations, chemical and biological monitoring, alert organization, ecological damages, ecotoxicological effects assessment, recovery and alteration of the river biology, return of the salmon, drinking water supplies, research programs, education of environmental scientists, and visions for the future.<BR/><I>Conclusion</I> The catastrophic pollution of the Rhine in November 1986 has triggered by the openly visible damages of the river biology that subsequently significant progress was made towards the prevention of such environmental catastrophes. The crucial risk reduction measures in the chemical industry, legal regulations and controls as well as chemical and biological monitoring of the river water quality were substantially improved. Politics and chemical industry have learned their lectures and have proceeded accordingly.<BR/><I>Recommendations</I> A drastic acute contamination, as it has happened at Schweizerhalle in 1986, is clearly recognizable by the toxic effects, which it is causing. This can lead to mitigation activities, which are positive considering a long-term perspective. However, the less obvious effects of chronic water pollution should receive more attention as well as the ongoing alteration of the biocenosis. A high water quality must be demanded for using water from the Rhine to produce drinking water. In that context, micropollutants should also be considered and particular attention should be payed to emerging contaminants.<BR/><I>Perspectives</I> The big chemical storehouse fire of 1986 had an important impact on the transboundary cooperation and has improved the willingness for international cooperation. The fire catastrophe of Schweizerhalle has triggered many activities in particular for the Rhine River. Overall, the effects are positive on the basis of a long-term perspective. The applied whole basin approach gives an example on a global basis for other river systems, which still are more heavily polluted.

The 1st Young Environmental Scientists (YES) Meeting took place in March (16–18) 2009 at the Institute for Environmental Sciences at the University of Koblenz-Landau, Landau Campus, Germany. This special students-only conference was organised under the umbrella of Society of Environmental Toxicology and Chemistry (SETAC) Europe by its Student Advisory Council (SAC). The SAC represents student members (master, diploma or Ph.D.) throughout every level of SETAC and provides additional advice, recommendations and new initiatives to the SETAC Europe Council.

Technical nonylphenol (tNP), used for industrial production of nonylphenol polyethoxylate surfactants, is a complex mixture of C<SUB>3−10</SUB>-phenols. The major components, 4-nonylphenols, are weak endocrine disruptors whose estrogenicities vary according to the structure of the branched nonyl group. Thus, accurate risk assessment requires isomer-specific determination of 4-NPs. Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/ToFMS) was used to characterize tNP samples obtained from seven commercial suppliers. Under optimal chromatographic conditions, 153−204 alkylphenol peaks, 59−66 of which were identified as 4-NPs, were detected. The 4-NPs comprised 86−94% of tNP, with 2-NPs and decylphenols making up 2−9% and 2−5%, respectively. The tNP products were analyzed for eight synthetic 4-NP isomers, and results were compared with published data based on GC/MS analysis. Significant differences were found among the products and between two samples from a single supplier. The enhanced resolution of GC × GC coupled with fast mass spectral data acquisition by ToFMS facilitated identification of all major 4-NP isomers and a number of previously unrecognized components. Analysis of tNP altered by the bacterium, <I>Sphingobium xenophagum</I> Bayram, revealed several persistent 4-NPs whose structures and estrogenicities are presently unknown. The potential of this technology for isomer-specific determination of 4-NP isomers in environmental matrices is demonstrated using samples of wastewater-contaminated groundwater and municipal wastewater.

A wide variety of antibacterial compounds is rapidly oxidized by O<SUB>3</SUB> and hydroxyl radical (<SUP><B>·</B></SUP>OH) during aqueous ozonation. Quantitative microbiological assays have been developed here or adapted from existing methods and utilized to measure the resulting changes in antibacterial potencies during O<SUB>3</SUB> and <SUP><B>·</B></SUP>OH treatment of 13 antibacterial molecules (roxithromycin, azithromycin, tylosin, ciprofloxacin, enrofloxacin, penicillin G, cephalexin, sulfamethoxazole, trimethoprim, lincomycin, tetracycline, vancomycin, and amikacin) from 9 structural classes (macrolides, fluoroquinolones, β-lactams, sulfonamides, dihydrofolate reductase inhibitors, lincosamides, tetracyclines, glycopeptides, and aminoglycosides), as well as the biocide triclosan. Potency measurements were determined from dose−response relationships obtained by exposing <I>Escherichia coli</I> or <I>Bacillus subtilis</I> reference strains to treated samples of each antibacterial compound via broth micro- or macrodilution assays and related to the measured residual concentrations of parent antibacterial in each sample. Data obtained from these experiments show that O<SUB>3</SUB> and <SUP><B>·</B></SUP>OH reactions lead in nearly all cases to stoichiometric elimination of antibacterial activity (i.e., loss of 1 mole equivalent of potency permole of parent compound consumed). The β-lactams penicillin G (PG) and cephalexin (CP) represent the only clear exceptions, as bioassay measurements indicate that biologically active products may be formed in the reactions of these two compounds with both O<SUB>3</SUB> and <SUP><B>·</B></SUP>OH. The active product(s) generated in the direct reaction of O<SUB>3</SUB> with PG appear(s) to be recalcitrant to further transformation by O<SUB>3</SUB>, though any biologically active products formed in the reactions of CP with O<SUB>3</SUB>, or of either PG or CP with <SUP><B>·</B></SUP>OH, are apparently deactivated by further reactions with O<SUB>3</SUB> or <SUP><B>·</B></SUP>OH, respectively. Thus, with few exceptions, it can be expected that municipal wastewater ozonation will generally yield sufficient structural modification of antibacterial molecules to eliminate their antibacterial activities, whether oxidation results from selective reactions with O<SUB>3</SUB> or from relatively nonselective reactions with incidentally produced <SUP><B>·</B></SUP>OH.

<em>Background and aim</em> Despite intensive and continuous stocking and improvement of water quality since the 1970s, fish populations, especially those of the grayling (<em>Thymallus thymallus</em>), have declined over the last two decades in the upper Danube River (Germany). In order to assess 1) possible links between molecular/biochemical responses and ecologically relevant effects, and 2) if ecotoxicological effects might be related to the decline in fish catches in the upper Danube river, sediment samples and fish were collected at different locations and analyzed using a weight-of-evidence (WOE) approach with several lines of evidence. The objective of the presentation is to introduce the conceptual framework and to review results of the ongoing study. As previously addressed by Chapman and Hollert (2006) a variety of lines of evidence can be used in WOE studies. Briefly, 1) a comprehensive battery of acute and mechanism-specific bioassays was used to characterize the ecotoxicological hazard potential. 2) Histopathological investigations and the micronucleus assay with erythrocytes were applied, analyzing <em>in situ</em> parameters. 3) Diversity and abundance of benthic macroinvertebrates and fish as well as 4) persistent organic pollutants, endocrine disrupting substances, limnochemical parameters and the concentration of heavy metals were recorded. To identify organic contaminants a spotential causes of sediment toxicity assays, 5) effect directed analysis was applied.

The Swiss Federal Railways (SFR) use glyphosate as the only herbicide for the chemical weed control on railway tracks. After the application on the railroad embankment the herbicide can be partly transported with the rainfall to the aquatic environment.<BR/>In order to assess the potential environmental pollution glyphosate and its main degradation product aminomethylphosphonic acid (AMPA) were analysed in selected drainage water of the railroad embankment from all over the railway system. The results were compared with studies in other European countries. Furthermore, the time-dependent concentration dynamics during one rain event was investigated at one selected sampling site.

Perfluorinated compounds are emerging persistent organic pollutants. Wastewater treatment plants are reported to be one of their primary sources. However; a standard analytical method for sludge samples has not been set up. A novel and rapid analytical method based on the liquid extraction; followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was set up for 7 perfluorocarboxylic acids (PFCAs) and their precursors, 6: 2 and 8: 2 unsaturated flourotelomer carboxylic acids (FTUCAs), and 2 perfluoroalkyl sulfonates vPFASs) and their precursors; 5 derivates of sulfonamide in sludge. The parameters of methanol extraction, including pH, sonication temperature and time, and eluent volume were optimized. The extraction method was optimized as neutral extraction under sonication at 40 °C for 10 min, and it was successfully used for the analysis of perfluorinated compounds in the sludge samples. The linear calibration curves were obtained in the ranges of 0. 1 - 20 μg/L for PFCAs and 6:2/8:2 FTUCA and 0. 25 - 50 μg/L for PFASs and their precusors with linear correlation coefficients larger than 0. 99. The recoveries of the target compounds ranged from 74% to 141% (except for FTUCAs) and the limits of quantification ranged from 0. 6 to 30 μg/kg (dry weight). The use of internal standards can well correct the ion suppression (or enhancement) induced by co-eluting components present in the sample extracts, and improve the quantitative accuracy.

Spontaneous mutations are not randomly distributed throughout a genome. Although mutation hotspots are found on genomes of a variety of species, mechanisms that generate the hotspots are not well understood. In eukaryotes, strong association between a regional nucleotide substitution rate and insertions/deletions (indels) was reported in a previous study, and the “indel-induced mutation” hypothesis was proposed. However, it is unknown whether the association exists even in prokaryote genomes. In this study, we conducted a systematic survey for the association in 262 complete genomes from 73 bacterial species. In these bacteria, the level of nucleotide diversity was negatively correlated with the distance from the closest indel, which is consistent with the eukaryote data. The same pattern was observed even after excluding noncoding sequences, indicating that the difference in functional constraints among genomic regions is not a primary cause of the correlation. In addition, the increase of nucleotide substitution rate was detected disproportionally on a lineage carrying a derived indel mutation, confirming the indel-nucleotide diversity association in the bacterial genomes. In some cases, the level of nucleotide diversity was more than 100 times higher in regions close to indels than in distant regions. Although further understanding of the molecular mechanism is required to test the hypothesis, these results suggest that the same mechanism for the indel–nucleotide diversity associations might exist in eukaryotes and prokaryotes and play an important role in molecular evolution.

We employed environmental tracers (<SUP>3</SUP>H-<SUP>3</SUP>He, noble gases, stable isotopes <SUP>18</SUP>O and <SUP>2</SUP>H) to study groundwater recharge and residence times in the strongly exploited North China Plain aquifer system in the area of Shijiazhuang, the capital of the Hebei province. Groundwater in the unconfined parts of the piedmont plain contains tritium down to depths of about 100 m and exhibits <SUP>3</SUP>H-<SUP>3</SUP>He ages of less than 40 years. <SUP>3</SUP>H-<SUP>3</SUP>He ages correlate well with sampling depth but less so with distance along a transect from the mountains in the west through the recharge area in the piedmont plain, indicating a minor role of lateral inflow compared to spatially distributed recharge. The increase of groundwater age with increasing thickness of the saturated zone combined with the steady groundwater table descent over the last decades implies an effective recharge rate of around 0.3 m/yr, mostly due to infiltration of precipitation and irrigation water. Despite the recycling of irrigation water, a water balance deficit remains, causing depletion of the aquifers. Anthropogenic modifications of the natural recharge regime appear to be reflected by a trend of increasing stable isotope ratios in groundwater of the last decades.

The principle of subsurface or in situ iron and arsenic removal is that aerated water is periodically injected into an anoxic aquifer through a tube well, displacing groundwater containing Fe(II). An oxidation zone is created around the tube well where Fe(II) is oxidised. The freshly formed iron hydroxide surfaces provide new sorption sites for soluble Fe(II) and arsenic. The system's efficiency is determined based on the ratio between abstracted volume with reduced iron/arsenic concentrations (V) and the injected volume (V<I><SUB>i</SUB></I>). In the field study presented in this paper, the small-scale application of this technology was investigated in rural Bangladesh. It was found that at small injection volumes (<1 m<SUP>3</SUP>) iron removal was successful and became more effective with every successive cycle. For arsenic, however, the system did not prove to be very effective yet. Arsenic retardation was only limited and breakthrough of 10 mg/L (WHO guideline) was observed before V/V<I><SUB>i</SUB></I>=1, which corresponds to arrival of groundwater at the well. Possible explanations for insufficient arsenic adsorption are the short contact times within the oxidation zone, and the presence of competing anions, like phosphate.

In a scientist discussion, the participants exchange arguments and try to challenge each other by asking the right questions. The discussion is aimed at increasing the participants' knowledge of the discussed problem. In this article, we propose a simulation model of knowledge and attitude dynamics, based on a social-psychological theory of persuasion. It considers relevant psychological factors like value orientation, peripheral cues, and argument quality. This model is used to investigate the in science of communication uncertainties on knowledge and attitude change during a two-persons discussion. The developed model predicts the accumulation of knowledge and is able to represent complex attitude dynamics. Monte Carlo and sensitivity analysis are applied to identifying the factors that have the biggest in science on the attitude dynamics.

Ende der 1980'er Jahre wurde bewusst, dass landwirtschaftliche Produkte in Australien wie Kartoffeln, Rüben, Getreide und Zwiebeln relativ hohe Cd-Gehalte aufweisen. Mitte der 90'er Jahre wurde vermutet, dass Phosphatdünger und atmosphärische Deposition die zwei Hauptquellen für die Cd Einträge in die Böden sind. Eine quantitative Analyse der möglichen Cd Einträge fehlte allerdings. Um geeignete Massnahmen zu planen ist aber eine solche Analyse unabdingbar.<br/> Daraus ergaben sich folgende 2 Hauptfragen: 1) Welche Cd Einträge in die Böden sind relevant und wie gross sind sie? 2) Was wären geeignete Massnahmen um diese Einträge und damit auch den Cd Gehalt in den Produkten zu verringern?<br/> Für die Beantwortung dieser Fragen wurde ein Stoffflussmodell für den Cd Haushalt in Australien und speziell für das Subsystem Landwirtschaft entwickelt. Kalibriert wurde das Modell mit Daten der Nationalen Australischen Statistik, Daten der Industrievereinigung, Literaturwerten sowie Daten aus Interviews mit Experten.<br/> Die Resultate bestätigen, dass atmosphärische Deposition die Hauptquelle ist (51%), gefolgt von Phosphatdünger (38%) und Hofdünger (6%).<br/> Das Modell zusammen mit dem Wissen über das System erlaubte mögliche realistische Szenarien für eine Reduktion der Cd Einträge zu diskutieren.

Emerging contaminants such as pharmaceuticals and biocides are released from sewage treatment plants and also from agricultural fields. They are increasingly monitored in surface and groundwater but are not yet included as priority compounds in European guidelines. Analysis of these mostly polar compounds and their sometimes relevant metabolites is more and more carried out by LC-MS-MS. The main elimination processes in sewage treatment plants are sorption and biodegradation. Both processes are difficult to predict in case of polar compounds and therefore fate studies are essential.

Reaching the Millennium Development Goals for Sanitation is a challenge. To address this challenge, numerous technological innovations have been developed. But with so many innovations and a wide range of existing technologies appropriate in different settings, difficulties with communication and knowledge dissemination hinder informed decision-making and the integration of all sanitation elements. This chapter describes a novel method for organizing and defining sanitation systems to facilitate informed decision-making and an integrated approach. Technologies are categorized based on their ‘Product-Process’ specificity and then linked into logical systems using a ‘Flowstream’ concept. Technologies are grouped and used to construct seven logical systems. Additionally, according to the flowstream, suitable technologies are grouped and given a score for each of the criteria. The advantages and shortcomings of the flowstream approach to sanitation system planning and the differences between ‘system’ and ‘technology’ are discussed and a set of terms and concepts that can be used to standardize the way in which sanitation is thought of and communicated about is proposed.

Kinetics of growth refers to the rate at which the number of individual cells (or, more general, of active biomass) changes in a defined system. However, the area of microbial growth kinetics consists not just of the simple dynamic recording of biomass increase as a function of time in a culture but it is more the extraction of parameters that allow to quantitatively formulate general principles, to construct mathematical models that allow to describe and predict microbial growth processes and that provide a basis for further experimentation. Growth kinetics are therefore an indispensable tool not only in the applied fields of industrial and environmental biotechnology, but also in fundamental areas such as microbial genetics, physiology, and ecology, including competition, selection, and evolution.

To grow and divide, microbial cells take up precursors and building blocks (nutrients) from the environment. In a wider sense, nutrients are also compounds that are not directly incorporated into cell material but are used by microbes to obtain the energy necessary to drive this synthesis and maintain cell integrity. Different nutritional types of microorganisms exist using different forms of carbon (CO<SUB>2</SUB> or reduced organic compounds) and energy (light or chemical energy) as the primary sources for biosynthesis. Nevertheless, the cellular composition of all microbial cells with respect to bulk components and the elemental composition is rather similar. Because of this, it is possible to estimate the general requirement of different nutrients for growth and to design and analyze microbial growth media. In well-designed growth media a particular identified nutrient is growth-limiting and determines the amount of biomass that can be formed, whereas all other nutrients are present in excess (Liebig’s principle). Cell metabolism and performance are strongly influenced by the nature of the growth-limiting nutrient. Therefore, many industrial fermentation processes are based on restricting the availability of a particular nutrient in order to force a strain into a physiological state favorable for production.

The increasing demand of potable water as well as process water is leading to scarcity of readily available water resources in many regions of the world. In order to preserve fresh water resources waste water reclamation can serve as a promising but technically challenging alternative to conventional water sources. Besides pathogens, organic trace pollutants cause major concerns in reclamation schemes. In this project, the removal of four micropollutants, more specifically bisphenol A, 17α-ethinylestradiol, 5-fluorouracil and cytarabine, from municipal wastewater treatment plant (WWTP) effluent was studied in laboratory scale experiments and in spiking experiments in a pilot plant combining sorption to powdered activated carbon (PAC) and retention by capillary nanofiltration (NF). Laboratory scale experiments evaluating adsorption isotherms and kinetics showed decreased adsorption capacities but increased affinities in the presence of natural organic matter. Spiking experiments showed that the combination of adsorption to PAC and NF retains micropollutants significantly better than direct NF. Retention of lipophilic micropollutants was increased up to 99.9%. Therefore, the PAC/NF process can be considered as an effective way to treat WWTP effluent for reuse.

Urban water cycles are threatened in many ways by human activities, including the discharge of chemicals by industrial and household effluents. Since more than a decade it has been recognised that the active ingredients of human pharmaceuticals contribute to the chemical contamination of urban surface waters and may pose a serious risk to the environment. Pharmaceuticals reach the aquatic environment due to their everyday use, excretion by humans and incomplete degradation in sewage treatment works. Their environmental concentrations are generally low. Due to their biologic activity, however, pharmaceuticals are considered as candidate compounds for low-level and chronic effects. Indeed, some pharmaceuticals, such as compounds interfering with reproductive hormones, provoke long-term effects on aquatic vertebrates in the ng/L range. Therefore, appropriate regulations for the environmental risk assessment as part of the approval of new medicines have been established. It was criticised, however, that these guidelines would not have been able to detect or predict the effects of some compounds with already known environmental impact. Thus, approaches for amending existing guidelines have been suggested. In this review, we give a brief overview on current and novel approaches for the prospective environmental risk assessment of human pharmaceuticals in the aquatic environment. In particular, we compare different strategies to identify potential ecotoxic effects and the possible applications within a regulatory framework. We indicate a number of tools that could improve the detection of compounds with potential low-level effects or hitherto unknown but relevant alternative mode of actions with implications for long-term effects.

Glaciological data derived from moraines, and multiproxy data from lake sediment cores (e.g. fossil pollen, diatoms, and isotope data) indicate cooling in the Central American tropics during the last ice age. Contrary to prior inferences, however, new lake core data from Lake Petén Itzá, lowland Guatemala, indicate that climate was not particularly dry on the Yucatan Peninsula during the last glacial maximum (LGM) chronozone, around 23,000–19,000 cal. yr BP. We present pollen and lithologic data from Lake Petén Itzá and an improved chronology for climate changes in lowland Central America over the last 25,000 years. The driest period of the last glaciation was not the LGM, but rather the deglacial period (∼18,000–11,000 cal. yr BP). Causes of climate shifts during the last glaciation are ascribed to precessional changes in insolation, the position of the Inter-Tropical Convergence Zone, and southward penetration of polar air masses.

The management of dams serves many purposes and goals all over the globe, and has important consequences for the downstream rivers and lakes. Among the more than 50,000 so-called large dams, the biggest are located in alpine regions. As a result, the water residence time in heavily dammed alpine valleys typically increased from a few days to several weeks, hydrological regimes shifted seasonally and sediment transport often decreased to half of its natural value. The occurrence of high flows responsible for most particle transport is reduced and particles are trapped behind the dams. These changes modify particle concentrations and particle size distributions, thermal regimes and water quality in downstream waters. As a result, downstream rivers and pre-alpine lakes often experience significant alterations in particle, carbon and nutrient cycling. Also described are common mitigation measures that are often applied in newly-planned damming management.

Electricity generation from hydropower is responsible for a large part of the human impacts on water resources in the Alps. Attempts at finding an encompassing mitigation approach to these impacts are often confronted with high levels of societal conflict. Therefore, an integrative approach has to consider both ecological and political/social aspects of this economic activity. In the following, we will present an integrative mitigation approach that was developed as an eco-label for electricity in Switzerland. This label was developed and implemented in the early 2000s and has meanwhile been accepted as an environmental standard for hydropower operation in many other countries. The chapter emphasizes the interdisciplinary competencies needed as well as the potential benefits of an integrative approach to the problem.

This chapter on urban water in large population centres like Halle/Saale and Leipzig (Germany) focuses on the source, distribution and transport behaviour of xenobiotics as indicator substances for anthropogenic impacts on urban water systems. The xenobiotics reported here are micropollutants including pharmaceuticals, personal care products (collectively known as PPCPs) and industrial chemicals, which show low concentrations in urban waters. Such chemicals can be endocrine disrupters or are otherwise eco-toxic. The concepts presented herein required a new methodology for assessing the impact of human activities on the urban water system and processes in urban watersheds. To this end, we used different approaches in relation to the hydrogeological and hydrodynamic settings of the cities of Halle and Leipzig. For the Halle urban area, a conceptual flow and transport model was developed based on interaction between the river Saale and groundwater, and mass fluxes were computed, based on water balance calculations. For Leipzig, as a first approach, we established a monitoring program that involved various urban land use types and investigated their influence on the urban water system. Multivariate statistics and integral pumping tests were applied to account for the spatially highly heterogeneous conditions and time-varying concentrations. At both sites, we demonstrated the use of indicators consisting of physico-chemical parameters, ions, isotopes and compound-specific patterns of xenobiotics. The chosen indicators of pH, temperature, electrical conductivity, redox conditions, nitrate, sulphate, chloride, boron, the isotopes of hydrogen, nitrogen, oxygen, sulphur and boron, as well as bisphenol A, carbamazepine, technical 4-nonylphenol (t-nonylphenol), galaxolide, tonalide, and gadolinium, helped to balance urban substance fluxes and assess urban effects on surface water quality. From our current quantification, it is clear that predicting contaminant behaviour in urban areas demands a detailed process understanding which cannot be derived from laboratory experiments or phenomenological analyses at the catchment scale. Through an installation of measuring equipment at the interfaces between the unsaturated and saturated zone as well as between ground- and surface water, in situ contaminant transport and fate can be quantified from the cm- up to the m-range.

Average concentrations of dissolved nutrients (NO<SUB>3</SUB>, DRP, K) in the large alpine rivers Rhine, Rhône, Ticino, and Inn, and in small alpine streams and glacier streams, are low compared to those in midland rivers. Concentrations of NO<SUB>3</SUB> in the large rivers clearly exceed background concentrations. In spite of limited anthropogenic activities in alpine catchments, DRP concentrations in large rivers exhibited a downward trend over the last 30 years. Time series of NO<SUB>3</SUB> concentrations were first increasing and then leveled off. Export coefficients of NO<SUB>3</SUB> and DRP in alpine streams fall in the range of those estimated for nonagricultural lands and forests on the Swiss Plateau. The chemical weathering rate of rock-forming minerals in alpine catchments is about 165 <U>+</U> 45 g m<SUP>-2</SUP> y<SUP>-1</SUP>, corresponding to an ablation rate of about 0.06 mm y<SUP>-1</SUP>. Rates are dominated by the reaction of carbonate-containin rocks with CO<SUP>2</SUP> and the dissolution of anhydrite, whereas the weathering of silicate minerals contributes little. Total chemical weathering rates are in the same range as the export rate of fine sediments, as part of physical weathering products. In this respect, alpine rivers differ distinctly from lowland running waters. Long-term observations also revealed small changes in concentrations and loads of geochemical constituents. An increase in water temperature may be one driver for these changes, although other factors also play a role.

This chapter aims to discuss the minimum set of key properties that describe nanoparticles (NPs) in aquatic environments, and to review suitable analysis and characterization methods. Special focus is on characterization of manufactured NPs and associated nanoscale processes (Gilbert and Banfield, 2005). Manufactured NPs have recently raised concerns because of their potential effects on human health and the environment (Colvin, 2003; Donaldson et al., 2004; Handy et al., 2008; Nel et at., 2006; Oberdorster et at., 2005). Therefore, the analytical demands related to both exposure and effect assessment are discussed. Atmospheric NPs and airborne exposure are not covered in this chapter, but within Chapters 5 and 8, and also reviewed elsewhere (Burleson et al., 2004; Maynard, 2000); Powers et at., 2007). One aim has been to bring together concepts and knowledge from analytical chemistry, (e.g. quantitative determination of chemical composition in nanoparticle ensembles, such as size fractions or on a single NP), the mature field of particle size analysis (mainly developed for micron particles) (Barth and Flippen, 1995), environmental colloid science (Wilkinson and Lead, 2007) and the young field of nanometrology (Graham, 2007).

Density-driven flows play an important role for deep-water renewal in lakes and are often essential for nutrient transport and oxygenation of the deep hypolimnion. Here, we give a qualitative description of the characteristics of density plumes, describe several processes that lead to density-driven flows and discuss the relevance of these processes in different lake types and under different environmental conditions.