Showing papers in "Acta Hydrochimica Et Hydrobiologica in 2005"

Endocrine Disrupters in the Aquatic Environment: An Overview

Abstract: Although a relatively new area of environmental research, the field of endocrine disruption has grown very rapidly, and currently many hundreds, perhaps even a few thousand, papers are published annually on the many different aspects covered by the field. As far as endocrine disruption in wildlife is concerned, most attention has been focused on aquatic organisms, for two reasons. Firstly, the aquatic environment receives most of the pollutants intentionally released into the environment, through effluents from wastewater treatment plants, and secondly because many of the best documented examples of endocrine disruption in wildlife are of partially or completely aquatic species. These two reasons are probably not unconnected, of course. Hence, aquatic organisms can receive continuous exposure to endocrine-disrupting chemicals throughout their lives, albeit usually to low concentrations of these chemicals. Analysis of effluents has identified many of the endocrine-disrupting chemicals present, and shown that these are both natural and man-made, and vary greatly in potency. Most attention has been directed to identifying the main estrogenic chemicals, because many of the effects reported in wildlife appear to be a consequence of ‘feminization’ of males. However, chemical analysis of effluents has also demonstrated that chemicals with other types of endocrine activity are present, such as androgens, anti-androgens, progestagens, etc. The effects (if any, of course) of such chemicals on aquatic organisms are unknown, and largely uninvestigated, presently. Much of the biological research has centred on the effects of estrogenic chemicals, especially to fish. These effects, such as elevated vitellogenin concentrations and intersexuality, have to date been studied almost exclusively at the level of the individual, and hence whether endocrine-disrupting chemicals cause population-level consequences is largely unknown (the undeniable effects of TBT on molluscs, leading to local extinctions, being the exception). It is my opinion that rather too much of the recent research has not advanced our understanding of endocrine disruption a great deal, and we are probably not much further forward now than we were five years or so ago. It is surely time to tackle some of the outstanding, unresolved issues, such as the impact of endocrine disruption at the population level, and the issue of how organisms respond when exposed to complex mixtures of endocrine active chemicals. Such research will not be easy, and will require multidisciplinary teams, including people with expertise in areas not yet involved in the field of endocrine disruption, such as mathematical modellers. However, until such research is done, it will not be possible to decide how important an issue endocrine disruption is to wildlife, and how that importance compares to the other factors adversely affecting wildlife, such as habitat loss, climate change, and the introduction of exotic species and novel diseases.

Use of plant bioassays for the detection of genotoxins in the aquatic environment

Abstract: The present article describes the use of plant bioassays for the detection of genotoxins in the aquatic environment and gives an overview of test methods, their detection spectrum for environmental mutagens and carcinogens and their limitations and pitfalls. The most widely used test systems are micronucleus assays with meiotic cells of Tradescantia and with meristematic root tip cells of Allium and Vicia. In the last years, protocols for single cell gel electrophoresis assays have been developed, which can be conducted with a variety of species. Also various gene mutation test procedures have been developed with plants but they have hardly ever been used in environmental studies. Plants detect a broad variety of environmentally relevant genotoxins, in particular directly acting compounds. Many pesticides and industrial chemicals caused positive results; plant assays are also a unique tool for the detection of DNA-reactive carcinogenic heavy metals in the environment. In many studies with complex mixtures, positive results were obtained which indicates that plants are sufficiently sensitive to detect effects without concentration of water samples. One of the shortcomings of the use of plants as indicators is their lack of sensitivity towards certain classes of promutagens such as nitrosamines, heterocyclic amines, and polycyclic aromatic hydrocarbons (PAHs). However, the former compounds are hardly encountered in the environment and PAHs can easily be detected chemically and in other mutagenicity tests. Taken together, the currently available data show that plant bioassays are a useful component of test batteries for environmental monitoring. Pflanzen-Bioassays zur Detektion von Gentoxinen im aquatischen Milieu Der vorliegende Artikel beschreibt die Anwendung von Bioassays mit Pflanzen zum Nachweis von Gentoxinen im aquatischen Milieu. Er beinhaltet einen Uberblick uber Testmethoden, Nachweisspektren von Umweltmutagenen und -kanzerogenen sowie mogliche Einschrankungen und Trugschlusse. Die haufigsten Testmethoden sind Kleinkerntests mit meiotischen Zellen von Tradescantia und meristematischem Wurzelgewebe von Vicia und Allium. In den letzten Jahren wurden auch Protokolle fur Einzelzellgelelektrophoresetests entwickelt, die mit einer Vielzahl an Arten durchgefuhrt werden konnen. Daruber hinaus wurden auch mehrere Genmutationstests mit Pflanzen entwickelt, doch diese Verfahren werden kaum in Umwelttests verwendet. Pflanzen detektieren ein breites Spektrum an umweltrelevanten Gentoxinen, vor allem direkt reaktive Substanzen. Viele Pestizide und Industriechemikalien fuhrten zu positiven Resultaten; Pflanzentests sind auserdem ein einzigartiges Hilfsmittel zur Detektion von DNA-reaktiven, kanzerogenen Schwermetallen in der Umwelt. In vielen Studien mit komplexen Gemischen wurden positive Effekte erhalten, dies zeigt, dass Pflanzen empfindlich genug sind, um auch ohne Aufkonzentrierung von Wasserproben als Indikatoren zu dienen. Ein Nachteil dieser Systeme ist die fehlende Empfindlichkeit pflanzlicher Organismen gegenuber bestimmten Klassen von Promutagenen wie Nitrosaminen, heterocyclischen aromatischen Aminen und polycyclischen aromatischen Kohlenwasserstoffen (PAK); die erstgenannten Chemikalien sind jedoch kaum in der Umwelt vorhanden, PAK konnen leicht durch chemische Testverfahren bzw. durch andere Mutagenitatstests detektiert werden. Zusammenfassend zeigen die derzeit verfugbaren Daten, dass Bioassays mit Pflanzen einen nutzlichen Bestandteil von Testbatterien fur Umweltprufungen darstellen.

Environmental Copper and Manganese in the Pathophysiology of Neurologic Diseases (Alzheimer's Disease and Manganism)†

Abstract: Alzheimer's disease (AD) is the most common form of dementia. Populations migrating from developing to industrialized countries seem to elicit a higher incidence and prevalence rate of AD, suggesting lifestyle and environmental factors to have a role in the pathophysiology of AD. One of its major neuropathological hallmarks is the deposition of Aβ peptides as amyloid plaques in the brain of AD patients. Aβ is proteolytically cleaved out of the larger amyloid precursor protein (APP). Cu and Mn are often found in drinking water and may have a neurotoxic potential. APP is involved in Cu homeostasis in mouse and man. In vitro observations and in vivo data obtained from APP mouse models provide strong evidence that APP overexpression enables intracellular Cu to be transported out of the cell. Disturbed metal-ion homeostasis with elevated serum Cu levels occurs in Alzheimer and Down's patients and lowered levels in post-mortem AD brain. We observed that bioavailable Cu has specific beneficial effects in an Alzheimer's disease mouse model. This should be regarded as a proof-of-concept for a prophylactic approach to overcome the observed CNS Cu deficiency in the brain of Alzheimer's disease patients. Manganism is a disorder with symptoms similar to that of Parkinson's disease. The precise mechanism how manganese can damage the nervous system is unknown. There is some evidence that iron and manganese may utilize similar transport systems. Epidemi ologic data strongly suggests that manganese enters the body primarily via inhalation and through the ingestion of manganese in drinking water. Kupfer und Mangan aus der Umwelt und die Pathophysiologie neurologischer Erkrankungen (Alzheimer-Krankheit und Manganismus) Die Alzheimer-Krankheit (AD) ist die haufigste Form der Altersdemenz. In Bevolkerungsgruppen, die aus Entwicklungs- in industrialisierte Lander ubersiedeln, steigen parallel dazu absolute und relative Haufigkeit der AD. Lebensweise und Umwelt scheinen demnach die Pathophysiologie der AD zu beeinflussen. Eines ihrer wichtigsten Merkmale ist die Ablagerung von Aβ-Peptiden in Form von Amyloidplatten im Gehirn. Das Aβ-Peptid entsteht proteolytisch aus einem groseren Vorlaufermolekul, dem Amyloid-precursor protein (APP). Cu und Mn kommen oft im Trinkwasser vor und konnten beide ein neurotoxisches Potential besitzen. APP ist in den Stoffwechsel von Cu in Maus und Mensch eingebunden. Beobachtungen in vitro und In-vivo-Daten aus Mausmodellen belegen zweifelsfrei, dass die Uberexpression von APP dem Cu das Verlassen der Zelle ermoglicht. In Patienten mit AD oder dem Down-Syndrom sind infolge Storung der Metall-Homoostase die Cu-Werte im Serum erhoht und im Gehirn verstorbener AD-Patienten erniedrigt. Wir selbst beobachteten, dass bioverfugbares Cu im Mausmodell Entstehung und Verlauf der AD mildert. Dies ist ein vielversprechender Ausgangspunkt fur die Suche nach Moglichkeiten, die Cu-Verarmung bestimmter Gehirnbereiche von AD-Patienten prophylaktisch zu unterlaufen. Der genaue Mechanismus, nach dem Mn das Gehirn schadigen kann, ist unbekannt. Es erreicht den Korper vermutlich unter Nutzung der Transportsysteme fur Fe vor allem per Inhalation und auf dem Trinkwasserpfad. Die Symptomatik des Manganismus ahnelt derjenigen des Parkinsonismus.

Is there a Human Health Hazard from Microcystins in the Drinking Water Supply

Abstract: Microcystins are cyclic heptapeptide toxins produced by a range of cyanobacterial genera. These cyanobacteria occur naturally in drinking water reservoirs subject to eutrophication, and in rivers and natural lakes. Because of the diversity of organisms, the toxins occur, from oligo-mesotrophic lakes in North Temperate latitudes, to hypertrophic tropical ponds. The toxins are responsible for numerous cases of injury and death of domestic animals, and human poisoning from drinking water. The initial poisoning includes hepatic cell death. This leads to secondary effects from liver deficiency, including jaundice and photosensitisation. The toxic effects are largely due to inhibition of phosphatase enzymes, acting to regulate protein phosphorylation. The consequences include structural damage, apoptosis and, at lower concentrations, cell cycle effects and tumour promotion. As there is no clear evidence for direct carcinogenesis by microcystins, they are classed as non-carcinogenic toxins in drinking water. Guideline Values for safe drinking water are derived from data for subchronic rodent toxicity, using the No Observed Adverse Effect Level (the highest dose giving no toxicity). To this dose are applied uncertainty factors, to calculate a Tolerable Daily Intake. On the basis of a standard bodyweight and water consumption the Guideline Value is determined for drinking water. For microcystin-LR the WHO have set a provisional Guideline Value of 1 μg/L for drinking water.

A Simple In Vivo Fluorescence Method for the Selective Detection and Quantification of Freshwater Cyanobacteria and Eukaryotic Algae

Abstract: A method for the rapid detection of cyanobacteria (blue-green algae) and their differentiation from eukaryotic algae in natural phytoplankton assemblages is presented. Fluorescence emission of photosynthetic pigments at 670 nm was measured using a microplate fluorescence reader when excited at two different wavelengths - 485 nm and 590 nm. The ratio of fluorescence excited at these wavelengths (590 nm/485 nm) was proportional to the ratio of cyanobacteria and eukaryotic algae, which was determined by the in situ spectrofluorometer for the phytoplankton quantification. The fluorescence intensity was equal to the total chlorophyll-a content. These two fluorescence values can provide the first warning on a development of potentially toxic cyanobacteria in water.

The Chemical Species Distribution of Aluminum in Composite Flocculants Prepared from Polyaluminum Chloride (PAC) and Polydimethyldiallylammonium Chloride (PDMDAAC)

Abstract: In order to improve the coagulation/flocculation efficiency of polyaluminum chloride (PAC), a composite flocculant of PAC and polydimethyldiallylammonium chloride (PDMDAAC), or PAC-PDMDAAC, was prepared. The chemical species distribution of aluminum in PAC and PAC-PDMDAAC, which has a close relationship with their coagulation/flocculation performance, was investigated by Al-Ferron complexation timed spectrophotometry and 27Al-NMR. The factors affecting the chemical species of aluminum in PAC-PDMDAAC, such as the weight concentration of PDMDAAC (Wp), basicity (B) of PAC, and viscosity (η) of PDMDAAC, were studied. The flocculation efficiencies of PAC-PDMDAAC, PAC and PDMDAAC were studied on a six-spindle multiple stirrer unit. The results showed that the aluminum species distribution in PAC-PDMDAAC depends on the Wp, B and η value. When the B value is 1.5 and η value is 1.22 dL/g, the composite flocculant with Wp = 15 % gives highest Alb and Al13 contents, and its flocculation efficiency is highest in the test flocculations. Speziesverteilung von Aluminium in Flockungsmittelmischungen aus Polyaluminiumchlorid (PAC) und Polydimethylallylammoniumchlorid (PDMDAAC) Zur Verbesserung der Koagulations- bzw. Flockungseffizienz wurden Flockungsmittelmischungen aus Polyaluminiumchlorid (PAC) und Polydimethylallylammoniumchlorid (PDMDAAC) bereitet. Da die Wirksamkeit dieser Flockungsmittel eng mit der Speziierung des Aluminiums zusammenhangt, wurde die Speziesverteilung des Aluminiums 27Al-NMR-spektroskopisch sowie photometrisch mit Hilfe der Al-Ferron-Komplexierungsreaktion untersucht. Flockungsversuche mit PAC-PDMDAAC, PAC und PDMDAAC wurden in einer Standard-Jar-Test-Apparatur durchgefuhrt. Es zeigte sich, dass die Speziesverteilung des Aluminiums in PAC-PDMDAAC vom Massenanteil des Wp PDMDAAC, der Basizitat (OH−/Al-Verhaltnis B) von PAC und der intrinsischen Viskositat η von PDMDAAC abhangt. Fur B = 1.5 und η = 1.22 dL/g zeigte die Mischung mit Wp = 15 % den hochsten Gehalt an Alb und Al13 und erwies sich bei den Flockungsversuchen als das effizienteste Flockungsmittel.

Flood induced heavy metal and arsenic contamination of Elbe river floodplain soils

Abstract: Although the qualities of the river water and the sediments of the river Elbe have greatly improved over the past twenty years, both the suspended matter and the sediments are still contaminated with heavy metals and arsenic (HM). This contamination exceeds the action values specified in the Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV). The status of floodplain soil contamination with HM along the entire German alluvial Elbe was investigated and evaluated, based on former research activities and recently performed analyses after the extreme flood event in August 2002 and the subsequent winter flooding. The section downstream of the river Mulde inflow was contaminated much higher than the upstream section. With the installation of permanently marked observation areas a tool for soil quality monitoring has been established for the future. Die hochwasserbedingte Belastung der Auen mit Schwermetallen und Arsen entlang der Elbe Obgleich sich die Flusswasser- und Sedimentqualitat der Elbe in den letzten 20 Jahren erheblich verbessert haben, sind die Schwebstoffe und schwebstoffburtigen Sedimente immer noch hoch mit Schwermetallen belastet. Dies fuhrt bei Bodenbildungen aus diesen Substraten haufig zur Uberschreitung der in der Bundesbodenschutz- und Altlastenverordnung (BBodSchV) festgelegten Masnahmewerte. Basierend auf fruheren Untersuchungen und aktuellen Erhebungen wahrend des extremen Hochwassers vom August 2002 und des folgenden Winterhochwassers wurde der gegenwartige Belastungsstatus der Boden in den Uberflutungsgebieten entlang der gesamten deutschen tidefreien Elbe ermittelt und bewertet. Dabei war der Flussabschnitt unterhalb der Muldemundung wesentlich hoher als der oberhalb gelegene belastet. Durch die Anlage dauerhaft markierter Beobachtungsflachen wird es ermoglicht, in Zukunft Veranderungen des Stoffbestandes exakt zu erfassen.

The Situation of PCDD/Fs and Dioxin-like PCBs after the Flooding of River Elbe and Mulde in 2002

Abstract: Following the Elbe and Mulde flooding in August 2002 a series of research and monitoring programmes were conducted to assess the contamination of the flooded areas with PCDD/Fs and related compounds and to identify related threats to the food chain. The present paper reports an overview of PCDD/F and dioxin-like PCB results obtained for soil samples from the floodplains and behind broken dikes, river sediments and feedstuff produced on the floodplains, and some products from animals fed with feedstuffs grown on the contaminated floodplains. The highest contamination levels in soil were found in periodically flooded pastureland riverside of the dikes. PCDD/Fs in most samples from pasture land exceeded the German threshold of 5 pg/g I-TEQ. Maximum concentrations in soil were up to 2100 pg/g I-TEQ. PCDD/Fs in agricultural soils, usually not flooded except during 2002, did not exceed the threshold of 40 pg/g. Maximum concentrations in soil were below 10 pg/g I-TEQ. PCDD/Fs in playgrounds and sporting areas did not exceed the threshold of 100 pg/g I-TEQ in soil, maximum concentrations were around 25 pg/g I-TEQ. Dioxin-like PCBs were of minor importance for the WHO-TEQ in soil and sediment but dominate the WHO-TEQ in Elbe fish. The soils behind broken dikes – only affected by the 2002 flood – were only marginally contaminated with PCDD/Fs. In contrast, most soils from the pasture lands riverside of the dikes, continuously affected by periodic flooding, revealed high contamination levels. This demonstrates that the 2002 flooding had only minor impact on the contamination of soils. The downstream concentration profile of Elbe sediments and alluvial soils identifies the rivers Mulde and Saale as important input sources. The related congener distribution suggests input from former metallurgic processing (magnesium) in the Mulde and Saale catchment. The downstream contamination profile in the sediments showed one order of magnitude lower PCDD/F levels and the peak contamination was located about 200 km further upstream when compared to the floodplains. Analytical surveys on feedstuffs cultivated on the contaminated floodplains did not reveal significant soil-grass transfer of PCDD/Fs, which indicates a low mobility of the PCDD/Fs present in the floodplains. However, co-ingestion of soil by grazing animals gave a clear signal of contaminant uptake and demonstrates the necessity of a careful agri-management of the floodplains of Elbe and Mulde. Die Situation im Hinblick auf PCDD/F und dioxinahnliche PCB nach der Flut von Elbe und Mulde im Jahr 2002 Nach der Elbe-Mulde-Flut im August 2002 wurden Untersuchungen auf PCDD/F und verwandte Verbindungen durchgefuhrt, um die Kontamination der uberfluteten Gebiete zu bewerten und eventuelle Gefahren fur die Nahrungskette abzuschatzen. Untersucht wurden in der vorliegenden Arbeit Bodenproben von uberfluteten Auen und hinter gebrochenen Deichen, Flusssedimente, von den Auen geerntete Futtermittel und einige Produkte von Tieren, die mit von kontaminierten Auen stammendem Tierfutter gefuttert worden waren. Das am starksten kontaminierte Bodenmaterial stammte von periodisch uberfluteten Weiden flussseitig der Deiche. Die meisten PCDD/F-Werte von Weideland-Bodenproben uberschritten den deutschen Grenzwert von 5 pg/g I-TEQ; die Maximalbelastung betrug bis zu 2100 pg/g I-TEQ. In Material von Ackerboden, die nur in 2002 uberflutet wurden, wurde der Grenzwert von 40 pg/g I-TEQ nicht uberschritten, die Maximalkonzentrationen in den Boden lagen unter 10 pg/g I-TEQ. Die PCDD/F-Werte auf Spiel- und Sportplatzen uberschritten nicht den Grenzwert von 100 pg/g I-TEQ im Boden, die Maximalkonzentrationen lagen bei etwa 25 pg/g I-TEQ. Dioxinahnliche PCB waren fur die Dioxinaquivalente WHO-TEQ in Boden und Sediment von geringer Bedeutung, aber sie bilden den Hauptanteil der WHO-TEQ in Fischen aus der Elbe. Die Boden hinter gebrochenen Deichen, die nur durch das Hochwasser in 2002 uberflutet wurden, normalerweise aber nicht, wiesen nur geringe Kontamination mit PCDD/F auf, im Gegensatz zum periodisch uberfluteten Weideland flussseitig der Deiche, das hoch kontaminiert war. Das zeigt, dass das Hochwasser 2002 nur geringen Einfluss auf die Belastung der Boden hatte. Die Konzentrationsprofile stromabwarts fur Sedimente und alluviale Boden weisen auf Mulde und Saale als wichtige Eintragsquellen hin. Die Kongenerenverteilung legt die Herkunft aus der fruheren Metallverarbeitung (Magnesium) im Einzugsgebiet der Mulde und Saale nahe. Im Vergleich zu den Auen wies das Kontaminationsprofil in den Sedimenten flussabwarts um eine Grosenordnung geringere PCDD/F-Niveaus auf, und das Maximum der Kontamination lag 200 km weiter flussaufwarts. Die Untersuchung von Futtermitteln, die auf den kontaminierten Auen angebaut wurden, ergab keinen signifikanten Boden-Gras-Ubergang von PCDD/F, was auf eine geringe Mobilitat der PCDD/F in den Auen hinweist. Jedoch gab es Hinweise auf direkte Aufnahme von kontaminiertem Bodenmaterial beim Grasen, so dass die Notwendigkeit eines sorgfaltigen Agrarmanagements der Auen von Elbe und Mulde gegeben ist.

Control of Microthrix parvicella in Activated Sludge Plants by Dosage of Polyaluminium Salts: Possible Mechanisms

Abstract: An effective control of the filamentous bacterium Microthrix parvicella in activated sludge wastewater treatment plants can take place by dosage of polyaluminium chloride, PAX-14. The mechanism how it works is largely unknown. The purpose of this study was to investigate in detail the mechanism by which PAX-14 controls M. parvicella. After addition of PAX-14, a reduction in substrate uptake, measured as uptake of radiolabelled oleic acid and trioleic acid under anaerobic conditions was observed by microautoradiography, indicating an effect on the physiology of M. parvicella or on the ability to transport substrate into the cell. Hydrophobic surface properties of the bacterium were not altered, but a significant reduction of exoenzyme activity was observed after PAX-14 addition. This was measured as bulk enzyme activity as well as surface-associated enzyme activity for esterase and lipase. New lipase production was not inhibited, indicating a need for a continuous addition of PAX-14 for an efficient control of M. parvicella. Furthermore, since PAX-14 is an efficient flocculating agent, it improved formation of dense flocs, so M. parvicella was embedded into floc material, making access to substrate difficult due to increased diffusional resistance. In conclusion, there seemed to be several reasons why PAX-14 could control M. parvicella: The physiology and particularly the lipase production were partly inhibited, the accessibility of substrate was affected, and a better flocculation occurred.

A study on arsenic and the heavy metals in the Mulde river system

Abstract: Analyses of water, suspended particulate matter, and sediment for the area drained by the river Mulde (Germany) for the early 90's show a high level of pollution in several sections of the river system. This was caused primarily by mining, and industrial and urban activity. The influence of the extreme “100-year-flood” into the Mulde and Elbe river systems as a result of the extremely high precipitation in the ore mountains (Erzgebirge) in August 2002 was studied. During the flood, large amounts of strongly polluted sediments were transported into the Freiberger Mulde and Zwickauer Mulde, and deposited on the flooded areas and along river banks in the Vereinigte Mulde. Concentrations of As and heavy metals in the flood sediments of the Freiberger Mulde were found to be very high. This is due primarily to waste dump leaching into the polluted part of the river near Freiberg. Studies in such strongly polluted area show that there is a permanent supply of pollutants from point and diffuse sources, and new sediments with the same level of pollution are formed in the river system. The study of the Bitterfelder Mulde river reservoir documents its function as a sink for suspended matter and heavy metals in the lower Mulde and Elbe system, even at extremely high flow rates. As a result of the flooding of the Lake Goitsche, large amounts of sediment were observed, particularly in the first subbasin Dobern. The deposited sediments contained large concentrations of As and heavy metals. Die Arsen- und Schwermetallverteilung in der Mulde Untersuchungen der Wasser, der suspendierten partikularen Substanz und der Sedimente im Einzugsgebiet der Mulde (Deutschland) Anfang der neunziger Jahre zeigten, dass eine hohe Arsen- und Schwermetallbelastung durch geogene (Mineralisationen und Lagerstatten) und anthropogene (Bergbau, Industrie und Besiedelung) Quellen in definierten Abschnitten des Flusssystems vorliegt. An dieser Ausgangssituation wurde der Einfluss eines extremen „Jahrhundert”-Hochwassers in den Flussen Mulde und Elbe als ein Ergebnis der extrem hohen Niederschlage im Erzgebirge studiert. Es wurde nachgewiesen, dass wahrend des Hochwassers grose Mengen hoch belasteter Sedimente in der Freiberger und Zwickauer Mulde transportiert und in den Uberflutungsflachen und Auenbereichen der Vereinigten Mulde abgelagert wurden. Besonders fur Arsen und Schwermetalle waren die Konzentrationen in den Flutsedimenten der Freiberger Mulde sehr hoch, was insbesondere auf die Abtragung von Haldenmaterial aus der Verhuttung im Hauptbelastungsgebiet Freiberg (Bereich Muldenhutten) zuruckzufuhren ist. Die Untersuchung der zeitlichen Entwicklung der Belastung in hoch belasteten Flussabschnitten wie z. B. der Freiberger Mulde bei Freiberg oder der Zwickauer Mulde bei Aue-Schlema nach dem Hochwasser zeigten, dass eine permanente Nachlieferung aus punktuellen und diffusen Quellen stattfindet und neue ahnlich belastete Sedimente im Flusssystem gebildet werden. Die Untersuchungen des Bitterfelder Muldestausees unterstrichen seine Funktion als Senke fur suspendierte partikulare Substanz, Arsen und Schwermetalle in der unteren Mulde, besonders bei extremen Durchflussraten. Die Flutung des Goitschesees fuhrte ebenfalls zur Ablagerung groser Sedimentmengen mit hohen Konzentrationen an Arsen und Schwermetallen, besonders im ersten Teilbecken Dobern.

Elimination of Swimming Pool Water Disinfection By‐products with Advanced Oxidation Processes (AOPs)

Abstract: Ozonation is a treatment step which was first applied in the 1960s in pool water treatment for disinfection as well as for oxidation of pool water contaminants. Contact time between ozone and pool water was identified to be of significance with an increased elimination efficiency regarding chloramines, trihalogenmethane formation potential and the permanganate index for longer reaction times. Oxidation via OH radicals might be the dominating pathway. In this study ozonation was compared with the ozone based advanced oxidation processes ozone/UV and ozone/hydrogen peroxide regarding the elimination efficiency of both disinfection by-products (DBPs) and DBP precursors. It was observed that AOPs in comparison to ozonation showed an increased elimination efficiency regarding total organic carbon (TOC), the organically bound halogens adsorbable on activated carbon (AOX) and AOX formation potential. A contact time of 3 minutes between pool water and oxidant turned out to be practically sufficient. Just for the trihalomethane (THM) formation potential ozonation showed a slight advantage compared to the AOPs because ozonation is a highly selective oxidant and OH radical reactions are known to produce small reactive molecules which are easier transformed to THMs. Combination of membrane filtration and AOPs resulted in an elimination of 10 to 90 % of the DBPs and their precursors. The ozone/hydrogen peroxide process is suggested for pool water treatment because of the higher elimination rates compared to ozonation and of economic reasons compared to the ozone/UV process.

Measurement of Foam Quality of Activated Sludge in MBR Process

Abstract: MBR (membrane bioreactor) process has been applied to wastewater treatment plants recently. It is well known that the most important point of the optimum maintenance is control of membrane clogging in the process. Suitable indices for operation and maintenance in MBR are desired to predict the timely cleaning period and carry out the effective cleaning of the membrane. A large amount of foam is sometimes produced in MBR facilities. Some foam seems to be produced by extracellular protein that is known to cause the membrane clogging. Therefore measurement methodology of foam quality produced by activated sludge in MBR process and characteristics of its extracellular polymer substances (EPS) were studied. The conclusions were: (1) EPS was able to be extracted by steaming treatment on the optimum condition at 105°C for 30 minutes. (2) Bingham viscosity and yield stress of activated sludge were measured. The yield stress was contributed by EPS and this suggested that EPS was one important factor for foaming. (3) The measurement of foam quality using a video camera showed good performance. The foaming power and the foam stability increased proportionally with the concentration of protein in EPS. It was clear that the protein concentration in EPS was strongly related to the foam quality and quantity. (4) The foaming power decreased by addition of MLSS. This decrease was caused by adsorption of EPS to MLSS. Foaming in an aeration tank will be an index for membrane cleaning requirement.

MTBE in Drinking Water Production – Occurrence and Efficiency of Treatment Technologies

Abstract: In Germany, the gasoline additive methyl tert-butyl ether (MTBE) is almost constantly detected in measurable concentrations in surface waters and is not significantly removed during riverbank filtration. The removal of MTBE from water has been the focus of many studies that mostly were performed at high concentration levels and centred in understanding the mechanisms of elimination. In order to assess the performance of conventional and advanced water treatment technologies for MTBE removal in the low concentration range further studies were undertaken. Laboratory experiments included aeration, granulated activated carbon (GAC) adsorption, ozonation and advanced oxidation processes (AOP). The results show that the removal of MTBE by conventional technologies is not easily achieved. MTBE is only removed by aeration at high expense. Ozonation at neutral pH values did not prove to be effective in eliminating MTBE at all. The use of ozone/H2O2 (AOP) may lead to a partly elimination of MTBE. However, the ozone/H2O2 concentrations required for a complete removal of MTBE from natural waters is much higher than the ozone levels applied nowadays in waterworks. MTBE is only poorly adsorbed on activated carbon, thus GAC filtration is not efficient in eliminating MTBE. A comparison with real-life data from German waterworks reveals that if MTBE is detected in the raw water it is most often found in the corresponding drinking water as well due to the poor removal efficiency of conventional treatment steps. MTBE in der Trinkwassergewinnung – Vorkommen und Entfernung wahrend der Aufbereitung Der Benzinzusatzstoff Methyl-tert-butylether (MTBE) wird nahezu standig in deutschen Oberflachengewassern nachgewiesen. Daruber hinaus wird er wahrend der Uferfiltration kaum eliminiert und ist somit im Rohwasser von Wasserwerken zu finden. In der Literatur wurden bereits Studien uber die Entfernung von MTBE durchgefuhrt, wobei diese meist bei hohen Konzentrationen erfolgten und das Verstandnis der grundlegenden Mechanismen der Elimination im Vordergrund stand. Im Rahmen der vorliegenden Studie wurden herkommliche und erweiterte Verfahren in der Trinkwasseraufbereitung auf ihr Eliminationspotential bezuglich MTBE in niedrigen Konzentrationen untersucht. Es wurden Laborexperimente zur Beluftung, Aktivkohlefiltration, Ozonung und Kombination Ozon/ H2O2 durchgefuhrt. Im Vergleich zu Benzol lasst sich MTBE durch Beluftung nur mit erhohtem Aufwand eliminieren; Ozonung zeigt bei neutralen pH-Werten keine Wirkung auf die MTBE-Konzentration. Bei der Kombination von Ozonung mit H2O2-Zugabe wird die MTBE-Konzentration deutlich erniedrigt; fur eine vollstandige Elimination jedoch wird eine wesentlich hohere Ozondosis benotigt als heutzutage in Wasserwerken ublich. MTBE wird daruber hinaus nur schlecht an Aktivkohle adsorbiert, so dass die Aktivkohlefiltration kein geeignetes Verfahren darstellt, um MTBE zuverlassig zu entfernen. Ein Vergleich mit Daten aus deutschen Wasserwerken zeigt deutlich, dass aufgrund der schlechten Eliminierungsleistung herkommlicher Technologien im Falle eines Auftretens von MTBE im Rohwasser ein Durchtritt ins Trinkwasser zu erwarten ist.

Dosing aluminum chloride to control microthrix parvicella

Abstract: To evaluate the effects of aluminum salts on floating sludge caused by Microthrix parvicella, the addition of AlCl3 was tested in a pilot scale activated sludge treatment plant fed with municipal wastewater. After enriching M. parvicella by dosing an emulsion of vegetable oil and Tween80, an average aluminum application rate per mass of mixed liquor suspended solids of 3.5 g kg-1 d-1 was applied. Specific sludge parameters such as the settling ability and the filament index were measured during the experiment. At the same time the effect of aluminum on the tendency to float and the hydrophobicity of activated sludge as well as on the morphology of M. parvicella was investigated. Microscopic investigations revealed a morphological modification of the filamentous bacterium during adding of AlCl3. M. parvicella was found mostly inside of the activated sludge flocs and appeared as a short filament. Concurrently, an improvement of the settling characteristics of the activated sludge was observed. The tendency to float and the hydrophobicity of activated sludge decreased during the dosing. This is of significant relevance in the attempt to prevent floating sludge accumulation in activated sludge systems. The decrease of hydrophobicity of activated sludge during AlCl3 dosage is probably related to the interaction of the aluminum species with the lipophilic substances and hydrophobic cell surface of M. parvicella (co-precipitation process).

A Preliminary Study of Chromophoric Dissolved Organic Matter (CDOM) in Lake Taihu, a Shallow Subtropical Lake in China

Abstract: The optical properties and spatial distribution of chromophoric dissolved organic matter (CDOM) in Meiliang Bay of Lake Taihu were evaluated and compared to the results in literature. Concentrations of dissolved organic carbon (DOC) ranged from 8.75 to 20.19 mg L-1 with an average of (13.10 +/- 3.51) mg L-1. CDOM absorption coefficients a(lambda) at 280 nm, 355 nm, and 440 nm were in the range 11.28...33.46 m(-1) (average (20.95 +/- 5.52) m(-1)), 2.42...7.90 m(-1) (average (4.92 +/- 1.29) m(-1)), and 0.65...2.44 m(-1) (average (1.46 +/- 0.44) m(-1)), respectively. In general, CDOM absorption coefficient and DOC concentration were found to decrease away from the river inflow to Meiliang Bay towards the lake center. The values of the DOC-specific absorption coefficients a*(lambda), given as absorption coefficient related to mass concentration of organic carbon (C) ranged from 0.28 to 0.47 L mg(-1) m(-1) at 355 nm. The determination coefficients between CDOM absorption and DOC concentration decreased with the increase of wavelength from 280 to 550 nm. The linear regression relationship between CDOM absorption at 280 nm and DOC concentration was following: a(280 nm) = 1.507 L mg(-1) m(-1) (.) DOC + 1.215 m(-1). The spectral slope S values were dependent on the wavelength range used in the regression. The estimated S values decreased with increasing wavelength range used. A significant negative linear relationship was found between CDOM absorption coefficients, DOC-specific absorption coefficients and estimated S values especially in longer wavelength range. The linear regression relationship between DOC-specific absorption coefficients at 440 nm and estimated S values during the wavelength range from 280 to 500 nm was following: a*(440 nm) = (-0.021 mu m (.) S + 0.424) L mg(-1) m(-1).

Developmental, Reproductive, and Demographic Alterations in Aquatic Wildlife: Establishing Causality between Exposure to Endocrine-active Compounds (EACs) and Effects†

Abstract: This brief overview discusses the difficulty of demonstrating causal associations between exposure to endocrine active compounds (EACs) and the occurrence of developmental, reproductive, or demographic disturbances in aquatic wildlife. While for biological responses at the suborganism level correlational or causal evidence of an EAC etiology has been established in a number of cases, well proven examples of ecological consequences of endocrine disruption are rather few in number. The attribution of causality is complicated due to (i) lack of data on EAC exposure and bioaccumulation, (ii) lack of specific biomarkers and endpoints, together with insufficient knowledge on the mechanisms and conditions by which EAC-induced disruption of endocrine functions translates into impaired organism development and reproduction, and (iii) insufficient understanding of the importance of species diversity in endocrine physiology and life histories for the consequences of endocrine disruption. Future research should address these gaps in our understanding of EAC exposure and effects, but additionally needs to pay more attention (i) to ecological determinants influencing the population-level consequences of the endocrine disruption of developImental and reproductive functions, and (ii) to the use of epidemiological principles and approaches. Veranderungen in der aquatischen Tierwelt im Hinblick auf Entwicklung, Reproduktion und Demographie: Herstellung eines kausalen Zusammenhangs zwischen Exposition an endokrin aktive Verbindungen (EAC) und Wirkungen Wahrend auf der suborganismischen Ebene in einer Reihe von Fallen biologische Wirkungen statistisch oder ursachlich auf endokrin wirksame Substanzen (EAC) zuruckgefuhrt werden konnten und es somit eine klare Evidenz fur eine EAC-Atiologie gibt, sind gut belegte Beispiele fur die okologischen Folgen endokriner Disruption eher selten. Die Herstellung kausaler Zusammenhange ist aus mehreren Grunden kompliziert: (i) Es gibt nur wenige Daten zu EAC-Exposition und Bioakkumulation. (ii) Es fehlen spezifische Biomarker und Endpunkte; zudem ist nur wenig bekannt, nach welchen Mechanismen bzw. bei welchen Bedingungen eine EAC-induzierte Disruption endokriner Funktionen in eine Beeintrachtigung der Entwicklung und Reproduktion des beeintrachtigen Organismus umgesetzt wird. (iii) Es ist noch ungenugend verstanden, von welcher Wichtigkeit Spezies-Unterschiede der endokrinen Physiologie und Life history fur die Folgen der endokrinen Disruption sind. Die zukunftige Forschung sollte sich auf die Lucken im Verstandnis zwischen EACExposition und -Wirkungen richten. Daruber hinaus sollte sie sich (i) starker mit den okologischen Einflussgrosen befassen, die die Folgen endokriner Disruption von Entwicklungs- und Fortpflanzungsfunktionen auf der Populationsebene bestimmen, sowie (ii) vermehrt epidemiologische Prinzipien und Ansatze nutzen.

Photoreactivation of Escherichia coli and Yersinia enterolytica after Irradiation with a 222 nm Excimer Lamp Compared to a 254 nm Low‐pressure Mercury Lamp

Abstract: Photoreactivation of Escherichia coli ATCC 11229 and Yersinia enterolytica ATCC 4780 after irradiation with a 222 nm krypton-chloride excimer lamp compared to a 254 nm mercury lamp was investigated under laboratory conditions. The bacteria samples were irradiated each with different doses of both wavelengths. After irradiation one sample of the bacteria was illuminated with fluorescent light, the other sample was stored in darkness to prevent photoreactivation. The inactivation curves were determined. Without photoreactivation, an irradiation of 69 J/m2 at 254 nm was sufficient for a 4 log reduction for E. coli, and only 59 J/m2 for Y. enterolytica. To get a 4 log reduction with following photoreactivation, 182 J/m2 were necessary for E. coli and 180 J/m2 for Y. enterolytica. After irradiation with the 222 nm excimer lamp the ratios were different. Without photoreactivation, an irradiation of 106 J/m2 at 222 nm was sufficient for a 4 log reduction for E. coli and 88 J/m2 for Y. enterolytica. With photoreactivation 161 J/m2 were necessary for E. coli to get a 4 log reduction and 117 J/m2 for Y. enterolytica. When the photoreactivation after irradiation is excluded, the mercury lamp with 254 nm clearly shows better results regarding inactivation. Whereas, when included, the excimer lamp with 222 nm wavelength obviously shows better results. Photoreaktivierung von Escherichia coli und Yersinia enterolytica nach Bestrahlung mit einem 222 nm-Excimerstrahler im Vergleich mit einem 254 nm-Niederdruck-Quecksilberstrahler Die Photoreaktivierung von Escherichia coli ATCC 11229 und Yersinia enterolytica ATCC 4780 nach Bestrahlung mit einem 222 nm-Krypton-Chlorid-Excimerstrahler im Vergleich zu einem 254 nm-Niederdruck-Quecksilberstrahler wurde unter Laborbedingungen untersucht. Proben beider Bakterienarten wurden mit verschiedenen Dosen beider Wellenlangen bestrahlt. Danach wurde zur Photoreaktivierung eine Probe Fluoreszenzlicht ausgesetzt, die andere dunkel gehalten, um diese zu verhindern. Dann wurden die Inaktivierungskurven ermittelt. Bei der Bestrahlung mit dem 254 nm-Quecksilber-Niederdruckstrahler waren ohne anschliesende Photoreaktivierung fur eine Inaktivierung von 4 log-Stufen 69 J/m2 fur E. coli und 59 J/m2 fur Y. enterolytica notig. Mit anschliesender Photoreaktivierung waren es dagegen 182 J/m2 fur E. coli und 180 J/m2 fur Y. enterolytica. Bei Bestrahlung mit dem 222 nm-Excimerstrahler zeigen sich deutliche Unterschiede bei den Verhaltnissen. Ohne anschliesende Photoreaktivierung war hier fur eine Reduktion von 4 log-Stufen eine Bestrahlung von 106 J/m2 fur E. coli und 88 J/m2 fur Y. enterolytica notig. Mit Photoreaktivierung waren es 161 J/m2 fur E. coli und 117 J/m2 fur Y. enterolytica. Wird die Photoreaktivierung ausgeschlossen, zeigt der Quecksilberstrahler bessere Ergebnisse bei der Inaktivierung, mit anschliesender Photoreaktivierung jedoch der Excimerstrahler.

The behavior of Ni(II), Cr(III), and Zn(II) in biological wastewater treatment process

Abstract: The purpose of this research was to investigate the effects of Ni(II), Cr(III), and Zn(II) on the treatment performance of sequencing batch reactor (SBR) system. The kinetics of adsorption study showed that the pseudo second-order reaction model provided the best description of the data obtained. From the Langmuir isotherm, the maximum adsorption capacities of Ni(II), Cr(III), and Zn(II) were 30 mg/g, 23 mg/g, and 18 mg/g, respectively. Cr(III) and Ni(II) were found to exert a more pronounced inhibitory effect on the bioactivity of the microorganisms compare to Zn(II). The increase of Cr(III) and Ni(II) concentration from 5 to 10 mg/L caused significant effect on the suspended solids (SS) and total organic carbon (TOC) removal efficiency in SBR system but vice versa in the case of Zn(II). The addition of powdered activated carbon (PAC) and termination of metal ions addition into SBR systems were carried out to investigate the capability of system recovery from the toxic effects of metal. Das Verhalten von Ni(II), Cr(III) und Zn(II) bei der biologischen Abwasserbehandlung An einem schubweise beschickten Reaktor (SBR) wurde der Einfluss von Ni(II), Cr(III) und Zn(II) auf die Leistungsfahigkeit der biologischen Abwasserbehandlung untersucht. Untersuchungen zum Sorptionsverhalten der Metalle ergaben, dass die Kinetik der Adsorption am besten durch ein Modell pseudo-zweiter Ordnung beschrieben wird. Aus der Langmuir-Isothermen wurde fur Ni(II), Cr(III) bzw. Zn(II) eine maximale Adsorptionskapazitat von 30 mg/g, 23 mg/g bzw. 18 mg/g erhalten. Cr(III) und Ni(II) wirkten starker hemmend auf die biologische Aktivitat der Mikroorganismen als Zn(II). Eine Konzentrationserhohung von 5 mg/L auf 10 mg/L hatte im Fall von Cr(III) und Ni(II) eine signifikante Verschlechterung der TOC- und der Partikelentfernung zur Folge, fur Zn(II) wurde der gegenteilige Verlauf beobachtet. Es wurde gepruft, inwieweit fur das SBR-System nach Beendigung der Metallionenzugabe oder nach Zugabe von Pulveraktivkohle ein Erholungseffekt festzustellen ist.

The In Situ Physiology of Pine Tree Like Organisms (PTLO) in Activated Sludge Foams

Abstract: The in situ physiology of filamentous bacteria with acute angle branching, or Pine tree like organisms (PTLO), from activated sludge foams was investigated with a focus on its response to hydrophobic substrates. Microautoradiographic studies revealed that PTLO are very selective in their substrate utilization in foams, only taking up oleic acid among many substrates tested, but carrying this out under aerobic, anaerobic, and anoxic conditions. Data from applying a combination of in situ techniques indicated that a high proportion of the PTLO were metabolically inactive in the foam. Most showed only low respiratory activity as detected with the redox dye CTC and low intensity signals from FISH probing with 16S rRNA targeted probes. A strong correlation was noticed between their accumulation of storage material in the form of polyhydroxyalkanoates and their intensity of fluorescent FISH signals. In situ surface properties of these PTLO as visualized by the adhesion of fluorescent hydrophobic spheres to individual filaments suggest that their relative hydrophobicities reflected their in situ cell viability. Active ectoenzyme activity was detected in many filaments but this activity did not correspond to the substrate uptake data.

Ecotoxicological Profiling of Transect River Elbe Sediments

Abstract: During the river Elbe flood in August 2002, large amounts of suspended organic matter were transported and settled in the course of the river. The aim of this study was to assess the quality of river Elbe sediments using chemical and biological methods. For this purpose 11 samples from river Elbe and 2 from tributaries were investigated. Two contact biotest systems, used to identify the ecotoxic potential of sediments, showed toxic effects in all sediments. Exposure was assessed by quantification of priority pollutants; however, no causal link to biological effects could be established. Effect qualities were characterised by testing organic sediment extracts in a biotest battery consisting of 8 test systems. Test systems varied in sensitivity to detect effects in the samples. Furthermore, samples differed in their ecotoxic potential. An effect-directed analysis was conducted in order to identify compounds responsible for the biological effects. Cause-effect relationships were established for mixtures of polycyclic aromatic hydrocarbons being partially responsible for toxic effects on algal reproduction; however the majority of the cause for toxicity remained unclear. Overall, it has to be concluded that Elbe sediments are not in accord with current quality goals. The chemical and the biological transect profile of the sediments indicate toxicant inputs from Czech Republic, river Mulde and diverse source. Okotoxikologisches Langsprofil von Elbsedimenten Wahrend des Elbehochwassers im August 2002 kam es zu einer massiven Verlagerung von partikularem organischem Material. Das Ziel diese Studie war es mit Hilfe von chemischen und biologischen Methoden die Qualitat der Elbsedimente zu bewerten. Zu diesem Zweck wurden 11 Proben aus der Elbe und 2 aus Elbnebenflussen untersucht. Zwei Sedimentkontakttests, die zur Charakterisierung des okotoxischen Potentials eingesetzt wurden, zeigten in allen Proben toxische Effekte an. Wichtige Kontaminanten wurden analysiert, allerdings lies sich kein Kausalzusammenhang zu den biologischen Effekten herstellen. Effektqualitaten wurden in den organischen Extrakten mit Hilfe einer Biotestbatterie bestehend aus 8 Biotests charakterisiert. Dabei zeigten die eingesetzten Testsysteme eine unterschiedliche Sensitivitat im Hinblick auf die Identifizierung von okotoxischen Effekten in den Proben. Auserdem konnte ein differenziertes Bild der Wirkpotentiale der einzelnen Proben erhalten werden. Durch eine Effekt-orientierte Analyse sollten fur die beobachteten Wirkungen verantwortliche Substanzen identifiziert werden. Ein Kausalzusammenhang zwischen Effekten auf die Algenreproduktion und der Belastung mit polycyclischen Aromaten konnte hergestellt werden, wobei die Mischung der identifizierten Substanzen aber nur fur einen Teil der Effekte verantwortlich war. Insgesamt muss gesagt werden, dass die Elbsedimente nicht im Einklang mit den Qualitatszielen sind. Aus dem chemischen und biologischen Langsprofil lassen sich Eintrage aus Tschechien, der Mulde und diffusen Quellen vermuten.

Multitemporal and Multispectral Remote Sensing Approach for Flood Detection in the Elbe-Mulde Region 2002

Abstract: The extreme flood event of the Elbe and Mulde Rivers in August 2002 caused, with its very sharp rise and decline of the water masses, a manifold of damage to the infrastructure as well as toxic deposits in the flooded areas. The paper gives a summary of the processing of multitemporal and multisensor remote sensing data for the purpose of monitoring this event. Methods and results for several thematic questions are presented and discussed. Procedures for the detection of flooded areas with operational satellite data (Landsat-ETM, IRS) are investigated. Further studies are performed regarding the classification of moisture classes in the flood plain in relation to the high water changes, the accumulation of sediments and silts for different land use classes and the erosive impact of the flood by using data with high spatial resolution from satellite (IKONOS) and from aircraft (Daedalus-Scanner). The time series of multispectral scanner data are very well suited for the spatial analysis of the damage and ecological risk, caused by the flood. The results correlate well with the data from in-situ measurements. At the same time they show how the gathering of samples can be optimized by using remote sensing data. The results can be directly integrated in existing GIS of the public authorities for the assessment and management of extreme flood events.

Identification of Organic Pollutants in Waters and Sediments from the Lower Mulde River Area

Abstract: The flood disaster along the Elbe and Mulde rivers in summer 2002 not only caused acute damage; in addition, it increased the risk of long-term release of pollutants. The area of the Lower Mulde river, that must be assessed as particularly critical in this context, because of the pollutants and refuse dumps accumulated in the industrial region Bitterfeld-Wolfen, was examined by GC-MS non target screening for organic substances in selected samples from groundwaters, river waters and sediment. Directed to the detailed qualitative analysis of the single sample, this approach supplied an overview of existing pollutants in the Lower Mulde river area, as well as knowledge about formerly unidentified organic substances, not covered by monitoring routines and associated with unassessed environmental risks. Newly identified chloroacetals and chlorinated products of formaldehyde-styrene chemistry may be useful as tracers for transport paths of pollutants, that might have changed in consequence of the flood. Furthermore, the chirality of the compounds provides a means to probe the extent of degradative microbial activity. Identifizierung von organischen Fremdstoffen in Wasser und Sediment aus dem Gebiet der unteren Mulde Die Flutkatastrophe des Sommers 2002 an Elbe und Mulde hat nicht nur akute Schaden verursacht, sondern fuhrte daruber hinaus zu erhohten Risiken der langerfristigen Freisetzung von organischen Fremd- und Schadstoffen. Das Gebiet der unteren Mulde, das in diesem Zusammenhang wegen der in der Industrieregion Bitterfeld-Wolfen akkumulierten Schadstoffe und Deponien als besonders kritisch eingestuft werden muss, wurde anhand ausgewahlter Proben aus Grundwasser, Flusswasser und Flusssediment durch GC/MS Non Target Screening auf organische Substanzen untersucht. Ausgerichtet auf die detaillierte Analyse der Einzelprobe lieferten diese Untersuchungen sowohl eine Ubersicht der im Gebiet der unteren Mulde vorhandenen Schadstoffe als auch neue Kenntnisse uber vorher nicht identifizierte und daher in Monitoring-Routinen unberucksichtigte organische Substanzen, die mit unbewerteten Risiken fur die Umwelt verknupft sind. Neu identifizierte Chloracetale und chlorierte Produkte der Formaldehyd-Styrol-Chemie konnten fur die Ausbreitung von Schadstoffen in Wasser und Sediment als Tracer-Substanzen dienen, deren Transportpfade sich als Folge der Uberflutungen verandert haben konnten. Daruber hinaus eroffnet die Chiralitat dieser Substanzen eine Moglichkeit, das Ausmas schadstoffabbauender mikrobieller Aktivitat festzustellen.

Flooding Induced Effects from the Mining Lake Goitzsche on Groundwater and Land‐use in the Bitterfeld Area

Abstract: The exceptional flooding event of the river Mulde in August 2002 led to an unexpected filling of the Goitzsche, an open-pit lignite mining lake, within two days. Due to this exceptional situation, the groundwater table in the vicinity of the lake rose several meters in the area of Bitterfeld. Over the last 100 years, this region has been affected by a large-scale contaminated aquifer of the former chemical industry complex Bitterfeld/Wolfen. Consequent to the rising groundwater level, the regional hydraulic situation and the groundwater flow direction changed entirely, as proven by hydraulic modelling results. Due to the heterogeneous aquifer conditions, the hydraulic importance was shown of a small scale channel-fill at the bottom of the upper aquifer. This predominant geological structure evidently affects the groundwater flow direction indicated by the modelled path lines. The resulting pathways of the contaminants can be used for the identification of exposure routes related to areas of high ecological sensitivity. The monitoring of highly soluble groundwater contaminants (e.g. benzene, TCE, cis-1,2-DCE), close to the flooding event, shows (irregular patterns of increasing, as well as decreasing, concentration values of related groundwater contaminants. Until the present, no consistent regional pattern can be recorded in the shift of the distribution of the concentration induced by the flooding event. Local differences in the concentration values are obviously more related to small scale variations within the Quaternary aquifer in terms of hydraulic conductivity and higher residual concentration of the contaminated matrix sediments. The temporal effects of concentration values ca be traced back, by most of the organic compounds, to distinct observation wells within the monitored time span at the starting point before flooding.

Bulking and Foaming in France: The 1999–2001 Survey

Abstract: To assess bulking in French wastewater treatment plants we developed a three-topic approach, including analysis of i) technical assistance annual reports, ii) a questionnaire, and iii) microscopic sample observations. A seasonal effect was very apparent on the average SVI (mL/g). Three situations appear to promote bulking according to statistical analysis and operators' comments: i) low-organic loading or rapid variation in organic loading, ii) raw sewage dilution or hydraulic loading variation, iii) rapid high-organic loading. Phosphorus removal by metallic salt addition leads to an average SVI reduction of 40 mL/g. Two situations in the sludge treatment process, which call for improvement, are: - The maintaining a high MLSS concentration in the aeration tank due to the limitation of sludge evacuation, - When storing sludge for several days or weeks in sludge thickening tank, thereby favoring the formation of septic compounds, which are subsequently reintroduced in the influent. Our study highlights Type 0092 as the most frequent filamentous microorganism observed followed by Microthrix parvicella. Thiothrix spp. ranks third.

Influence of a Xenobiotic Mixture (PCB and TBT) Compared to Single Substances on Swimming Behavior or Reproduction of Daphnia magna

Abstract: Aroclor 1254, a technical PCB mixture (polychlorinated biphenyls) and TBT (tributyltinchloride) are environmental pollutants that cause a broad spectrum of acute toxic and chronic effects in aquatic animals. In this paper, the sensitivity of Daphnia magna to chronic exposure to mixed xenobiotics was evaluated under laboratory conditions. The results show that xenobiotic mixtures (50 % each of the single compounds) were more toxic than individual xenobiotics alone. By measuring behavioral parameters of animals, it becomes evident that exposure to single xenobiotics significantly affects daphnids: exposure led finally to a rapid decrease in mean swimming activity and also caused changes in preferred swimming depth, with daphnids preferring the upper layers of aquaria. The mixture altered the swimming behavior even more strongly compared to the group stressed by single chemicals. Finally, all daphnids sank to the bottom of the aquaria, still alive, but inactive at the end of the exposure period. In addition, we investigated the reproductive capacity (number of newborn per female and day). PCB did not affect the number of newborn significantly, TBT-stress led to an evidently decreased number of young daphnids and the xenobiotic mixture decreased reproduction even more. In conclusion, we found significant effects of the single compounds as well as approximately additive (swimming behavior) and synergistic (reproduction) effects of the chemical mixture on daphnids indicating the possibility of dramatic ecological consequences of the occurrence of mixed xenobiotic substances in the aquatic environment. Einfluss einer xenobiotischen Mischung (PCB und TBT) auf Schwimmverhalten oder Reproduktion von Daphnia magna Aroclor 1254, eine technische PCB-Mischung (polychlorierte Biphenyle), und TBT (Tributylzinn) sind Umweltbelastungen, die ein breites Spektrum akut toxischer und chronischer Wirkungen in aquatischen Tieren verursachen. Untersucht wird die Sensitivitat von Daphniamagna bei chronischer Exposition gegenuber gemischten Xenobiotika unter Laborbedingungen. Die Ergebnisse belegen, dass xenobiotische Mischungen (50 % jeder Substanz) starker toxisch wirken als jede Substanz fur sich allein. Durch Messung von Verhaltens-Parametern der Tiere wird deutlich, dass die Exposition gegen einzelne Xenobiotika Daphnien signifikant beeinflusst: Die Wirkung fuhrt letztlich zu einer rapiden Abnahme der Schwimmaktivitat und verursacht bei den Daphnien Veranderungen in der Aufenthaltstiefe gegenuber den sonst bevorzugten oberen Schichten eines Aquariums. Die Stoffmischung verandert das Schwimmverhalten starker als die Einzelstoffe: Zu Versuchsende sinken alle Daphnien lebend, aber inaktiv zu Boden. Die zusatzlich untersuchte Reproduktionskapazitat (Anzahl der Neonaten je Weibchen) zeigt: PCB beeinflusst die Zahl der Neonaten nicht signifikant, TBT-Stress fuhrt zu einer deutlich verringerten Zahl junger Daphnien und die Mischung beider Stoffe senkt die Reproduktion noch starker. Zusammenfassend wurden signifikante Wirkungen der Einzelstoffe beobachtet sowie additive (Schwimmverhalten) als auch synergistische (Reproduktion) Wirkungen der Stoffmischung. Dies indiziert die Moglichkeit dramatischer okologischer Konsequenzen aus dem Vorkommen gemischter xenobiotischer Stoffe in der aquatischen Umwelt.

Effect of Single Species or Mixed Algal (Chlorella vulgaris and Scenedesmus acutus) Diets on the Life Table Demography of Brachionus calyciflorus and Brachionus patulus (Rotifera: Brachionidae)

Abstract: We tested the effect of two algal diets (Chlorella vulgaris at 1 · 106 cells mL−1and Scenedesmus acutus at 0.57 · 106 cells mL−1) offered alone or in combination (50 % each, 75 % or 25 % of either alga), at a total dry weight of 14.2 μg mL−1on the life table demography of two rotifer species, Brachionus calyciflorus and Brachionus patulus. Data on fecundity indicated that, for any given algal food type or combination of food types, B. calyciflorus had a higher rate of offspring production than B. patulus. Regardless of the rotifer species, the average lifespan varied from 4 to 6 days. The gross and net reproductive rates were higher for B. calyciflorus than for B. patulus. These values ranged from 45 to 71 offspring female−1 lifespan−1 and 15 to 24 offspring female−1 lifespan−1, respectively, for B. calyciflorus. Generation times (around 4…5 days) were similar for both rotifer species in most of the treatments. Whatever the algal food combination, the rate of population increase (d−1) of B. patulus was less than half (i.e. 45 %) of that for B. calyciflorus. The observed differences in the life history variables of Brachionus probably explain species-specific adaptations to the changing phytoplankton composition occurring seasonally in natural waterbodies. Die Wirkung einer Diat von einzelnen oder gemischten Algen (Chlorella vulgaris und Scenedesmus acutus) auf die Lebenstafel-Demographie von Brachionus calyciflorus und Brachionus patulus (Rotifera: Brachionidae) Untersucht wird die Wirkung von zwei Algen-Diaten (Chlorella vulgaris, 1 · 106 Zellen mL−1 und Scenedesmus acutus, 0.57 · 106 Zellen mL−1) bei alleinigem Angebot oder in Kombination (50 %, 75 %, 25 % Anteil jeder Alge) bei einer Summe von 14.2 μg L−1 Trockenmasse auf die Lebenstafel-Demographie zweier Rotatorien: Brachionus calyciflorus und Brachionus patulus. Die Daten zur Fruchtbarkeit zeigen bei jeder Art der Nahrung fur B. calyciflorus eine hohere Nachkommensrate als fur B. patulus. Die mittlere Lebensspanne liegt fur beide Arten zwischen 4 und 6 Tagen. Die Brutto- und Nettoreproduktionsraten sind fur B. calyciflorus (45…71 Nachkommen je Weibchen und Lebensspanne) hoher als fur B. patulus (15…24 Nachkommen je Weibchen und Lebensspanne). Die Generationsdauer ist mit 4 bis 6 Tagen fur beide Arten in den meisten Versuchsansatzen ahnlich. Bei jeder Futterkombination betrug die Wachstumsrate der Population (d−1) von B. patulus weniger als die Halfte (45 %) jener von B. calyciflorus. Die beobachteten Differenzen in den Variablen der Lebensgeschichte von Brachionus erklaren wahrscheinlich artspezifische Adaptionen an die wechselnde saisonale Zusammensetzung des Phytoplanktons in naturlichen Gewassern.

Comparison of Different Monitoring Programs of the 2002 Summer Flood in the River Elbe

Abstract: The water quality of the river Elbe near Magdeburg represents the pollution situation of the middle course of the river Elbe under normal discharge conditions. In order to identify critical changes in the water quality caused by the century flood in August 2002, numerous measurement programs were launched accompanying the flood wave. This paper compares and discusses results based on different sampling strategies and analytical methods of three institutions mainly using the example of trace metals. Vergleich verschiedener Untersuchungsprogramme wahrend des Sommerhochwassers der Elbe 2002 Die Wasserbeschaffenheit der Elbe bei Magdeburg spiegelt unter normalen Abflussbedingungen die Belastungssituation der Mittleren Elbe wider. Zur Erfassung der veranderten Belastungssituation wahrend des Jahrhunderthochwassers 2002 wurden verschiedene, die Flutwelle begleitende Messprogramme gestartet. Im vorliegenden Beitrag werden die Ergebnisse der zum Teil auf unterschiedlichen Probenahmestrategien und Messmethoden basierenden Programme verschiedener Einrichtungen, insbesondere im Hinblick auf Spurenelemente, untereinander verglichen und diskutiert.

Fate of Facultative Pathogenic Microorganisms during and after the Flood of the Elbe and Mulde Rivers in August 2002

Abstract: Extreme precipitation in August 2002 led to the flooding of large areas of the rivers and Mulde in the eastern part of Germany. Furthermore, flooding of villages and towns impacted also the local sewage systems leading to a release of untreated water into the river where high abundances of faecal bacteria might be dangerous. After the retreat of the flood, mud enriched by an unknown degree with facultative pathogenic microorganisms remained. High bacterial cell counts were observed in the cellars of the flooded houses, the playgrounds, and the streets forming a pathogenic reservoir. This is especially important in situations where many persons try to prevent and to repair flood damages. The high cell counts were not observed in open water and in wells implying that the cellars were a special niche for the survival of bacteria. The isolates obtained from media specific for facultative pathogenic bacteria showed a high biodiversity and a surprisingly high degree of multi-resistances against antibiotics. The origin of these resistances was not the river water because isolates from the Elbe river showed much lower multi-resistances than those from the flood water. Therefore, the multi-resistant bacteria are assumed to come from flooded sewage plants or from farms. Our results demand a closer monitoring of the sources of multi-resistant bacteria during future flooding events to protect humans from infections by multi-resistant bacteria. Das Schicksal fakultativ pathogener Mikroorganismen wahrend und nach der Flut von Elbe und Mulde im August 2002 Extremniederschlag fuhrte im August 2002 zur Uberflutung groser Gebiete entlang der Elbe und der Mulde im ostlichen Teil Deutschlands. Des Weiteren beeinflusste die Uberflutung von Stadten und Dorfern auch die lokalen Klaranlagen, was zum Eintrag ungeklarter Abwasser in die Flusse fuhrte und damit zu einer moglicherweise gefahrlich hohen Belastung mit Fakalbakterien. Nach dem Ruckgang der Flut blieb vielerorts Schlamm zuruck, der zu einem unbekannten Grad mit fakultativ pathogenen Mikroorganismen angereichert war. Es wurden hohe Bakterienzahlen in den Kellern uberfluteter Hauser, auf Spielplatzen und in den gefluteten Strassen gefunden, die ein pathogenes Reservoir bildeten. Dies ist besonders dort problematisch, wo viele Personen Uberflutungen zu verhindern suchen bzw. mit Aufraumarbeiten beschaftigt sind. Die hohen Zellzahlen wurden jedoch nicht in offenen Gewassern und Brunnen beobachtet, was darauf hindeutet, dass Keller spezielle Nischen fur das Uberleben von Bakterien darstellen. Isolate, die auf speziellen Medien gewonnen wurden, die fur pathogene Bakterien spezifisch sind, zeigten eine hohe Biodiversitat und ein uberraschend hohes Mas an Multiresistenz gegenuber Antibiotika. Der Ursprung dieser Resistenz lag nicht im Flusswasser, weil direkt aus der Elbe gewonnene Isolate eine wesentliche geringere Resistenz zeigten als solche aus dem Flutwasser. Es wird daher angenommen, dass die multiresistenten Bakterien aus den uberfluteten Klaranlagen oder dem Farmland stammen. Unsere Ergebnisse verlangen eine genauere Untersuchung dieser Quellen fur multiresistente Bakterien bei Flutereignissen, um die betroffenen Menschen vor Infektionen durch diese Krankheitserreger zu schutzen.

Non-famous scum bacteria : Biological characterization and troubleshooting

Abstract: Scum biocenoses in activated sludge nutrient removal plants besides nocardioform actinomycetes and Microthrix parvicella frequently accommodate other conspicuous organisms such as Eikelboom types 0041/0675, 0581, 0092, and 1851, as well as Nostocoida limicola-like organisms. In the scum fraction of high load plants often bacteria of type 1863 and non-filamentous actinomycetes are found. Many of these morphologically distinguishable scum bacteria are so-called morphotypes belonging to various groups or genera of bacteria as was proved by fluorescence in situ hybridization (FISH). Aim of this paper is to summarize our respective actual findings and the difficulties to provide practitioners with effective troubleshooting measures for these organisms.

Estimate of the Eutrophication Process in the Gruža Reservoir (Serbia and Montenegro)

Abstract: The Gruža Reservoir (located at 238…269 m a. s. l., volume 64.6 · 106 m3, surface 934 ha, drainage area 318 km2, max. depth 31 m, mean theoretical retention time 22 months) was investigated during the years 1996 to 2001. The obtained values of trophic state parameters (9…200 μg L−1 total phosphorus, 3…99 μg L−1 chlorophyll-a, and 0.5…2 m transparency) indicate that water of the Gruža Reservoir is eutrophic according to three types of classification: Carlson, OECD, and Jones and Lee. It was noticed that values of average biomass abundance are large in the Gruža Reservoir, and they could indicate a richer trophic state. When these indices are cited in connection with parameters of the trophic state, it is apparent that the Gruža Reservoir can be classified as a eutrophic water on the basis of total phosphorus content of chlorophyll-a and hypertrophic water with respect to transparency. Einschatzung des Eutrophierungsprozesses im Stausee von Gruža (Serbien und Montenegro) Der Stausee von Gruža (238…269 m NN, Volumen 64.6 · 106 m3, Oberflache 934 ha, Einzugsgebiet 318 km2, max. Tiefe 31 m, mittlere theoretische Aufenthaltszeit 22 Monate) wurde in den Jahren 1996 bis 2001 untersucht. Die Messwerte der trophischen Parameter (9…200 μg L−1 Gesamtphosphor, 3…99 μg L−1 Chlorophyll-a, 0.45…2 m Sichttiefe) belegen, dass der Stausee von Gruža eutrophen Status hat nach den drei Klassifikationen: Carlson, OECD sowie Jones und Lee. Die hohen Werte der mittleren Biomasse bestatigen den stark eutrophen Zustand. Hinsichtlich der Trophie-Indices ist der Stausee eutroph in Bezug auf Gesamtphosphor und Chlorophyll-a und hypertroph mit Bezug auf die Sichttiefe.