Imprägnierte Filterpapiere für die Wasserreinigung

With special filter materials it is possible to eliminate the heavy metals lead, copper and nickel and arsenic from water by sorption resp. chemical bounding. After a reaction time of 24 hours the reduction rates were between 97% and >99,9%.     

Biozide in Gebäudefassaden – ökotoxikologische Effekte, Auswaschung und Belastungsabschätzung für Gewässer

Background, aim and scope Sources of organic micropollutants occuring in surface waters are often unknown. Regarding environmental risk assessments for surface waters, construction materials have as till now, not been given much consideration, although biocides used as preservatives are known to reach urban storm water runoff. The study focused on biocides for facades coatings and aimed (1) to determine ecotoxicological effect values, (2) to quantify the leaching behaviour and (3) to assess the environmental risk for surface waters using a dynamic transport model. Materials and methods Eight biocides used in resin based facade coatings were investigated. Some biocides are substances known as pesticides for agricultural purposes like diuron, carbendazim and terbutryn. Ecotoxicological effect values for aquatic organisms were determined for every biocide. Leaching of four biocides from a render under UV-irradiation has been investigated in the laboratory including the influence of varying temperatures. Using 80 irrigation intervals over 28 days, facade runoff was sampled and followed by biocide chemical analysis. The total losses were calculated based on the concentration patterns. These data were used for modelling the transport of cybutryn from facades to surface waters. Biocide specific effect values and leaching characteristics have been taken into consideration. Results Acute and chronic effect values as well as predicted no effect concentrations for the investigated biocides indicate their high potential to affect aquatic organisms. The leaching of four biocides (diuron, terbutryn, cybutryn, carbendazim) from the facade render under the experimental conditions delivers high concentrations in the beginning followed by an exponential decrease. Rising temperature increased the concentration of biocides in the runoff. The total losses were between 7?% and 29?% depending on the substances. More than half of the losses occur in the runoff within the first 15 min of runoff from a 60 min irrigation cycle. The modelling result for cybutryn underlines its high environmental risk for small surface waters. Discussion The leaching of the biocides, their potential ecotoxic effects and persistence show clearly that the environmental risk for surface waters and soils seems to be high for certain biocides; whereas for others the risk seems to be significantly lower. With respect water quality criteria, polluted facades runoff has to be diluted before runoff can enter the discharge. Diuron and carbendazim are however also used as pesticides and preservatives for other materials and cybutryn is also used as an antifouling agent. All pathways have to be evaluated in order to identify relevant sources and to act more efficiently with respect to water and soil protection. Conclusions Concentrations with high environmental risk are expected at new facades, especially at facades with thermal insulation. With the given low predicted no effect concentrations in a range of a few ng/L and large amounts of biocides applied in paints and renders, the environmental risk for common biocides used in facade coatings has to be investigated in laboratory and field scale. It seems plausible that source control measures as the most efficient and sustainable precautionary principle need to be evaluated. Recommendations and perspectives Biocides and additives applied in construction materials have to be taken into consideration as relevant sources when evaluating the quality of storm water runoff, discharge into urban areas and the impact to soil and surface waters. A sustainable construction material management and storm water management are required. It is expected that ongoing laboratory and field studies with exterior paints, renders and flat sheets for waterproofing containing biocides and additives will give further insight into their environmental impact.     

Entwicklung von Prüfwertempfehlungen für ausgewählte Schadstoffe zum Schutz des Bodens als Lebensraum für Bodenorganismen

Goal and Scope

In the German Federal Soil Protection and Contaminated Sites Ordinance there are no ecotoxicological trigger values for the protection of soil as a habitat for soil organisms. The objective of this study was to derive preliminary trigger values for the habitat function of soils. This was done by collecting data on the impact of priority pollutants on soil organisms and plants followed by the parallel use of the Factorial Application Method (FAME) and Distribution Based Extrapolation (DIBAEX) and a final verification of the plausibility of the calculated trigger values by means of an ecotoxicological test battery.

Methods

Data on the effects of pollutants on soil organisms and plants were recorded in a specific data base (Soil Value). Subsequently, we derived so-called ‘working trigger values’ using the extrapolation methods FAME (factorial application method) and DIBAEX (distribution based extrapolation). In the second phase of the project, we verified experimentally the plausibility of these values by means of an ecotoxicological test battery. Test substrate was a sandy soil with low sorption capacity and organic carbon content which was mixed with fresh pollutants (e.g. heavy metal salts) and polluted soil material from contaminated sites (aged contamination), respectively. Organisms tested were microorganisms, plants, earthworms, springtails and nematodes.

Results and Conclusions

We calculated working trigger values for 12 pollutants based on 900 datasets compiled in he data base. The laboratory investigations showed the freshly added contaminants to be less strongly adsorbed to the soil than those added by the use of contaminated soil material. Nevertheless, aged contaminations displayed often the same inhibitive effects as the freshly added chemicals. The results achieved in the second phase of the project were also recorded in the Soil-Value database. Based on the new data set, final trigger values were derived for the experimentally tested substances.

Outlook

The procedure described in this contribution exemplarily for copper can be used for the derivation of recommended trigger values for the pathway soil ? soil organisms. Besides copper, preliminary trigger values were derived for zinc, mercury, lead and HCH.     

Ableitung ökotoxikologisch begründeter Bodenqualitätskriterien am Beispiel Arsen

Background

A vast amount of data on the concentration of substances in soils is being generated in environmental monitoring programmes. This data has to be assessed in terms of effects on terrestrial biota. Benchmarks for such an assessment have been missing up to now. This gap has been filled by the development of a concept for the derivation of ecotoxicologically based soil quality criteria (SQC) and the application of this concept to environmentally relevant substances.

Objectives

The derivation method was applied to arsenic. The derivation process was described in detail from the compilation of data regarding effects on microbial processes, plants, and soil invertebrates to the formulation of a recommendation for an SQC.

Methods

The conceptual framework for the derivation of ecotoxicologically based SQC was developed after reviewing national and international concepts for the assessment of the effects of substances on terrestrial communities. For the assessment of arsenic effects, all relevant biotic processes and trophic levels have been taken into account. Moreover, soil characteristics that may affect the toxicity to biota have been reviewed.

Results

Effects of arsenic on biota may occur at soil background concentrations or slightly above. There are only a few studies in which the influence of soil characteristics, such as soil pH, soil texture, and soil organic carbon, on the effects of arsenic has been investigated systematically. That is why the SQC was oriented on soil background concentrations for sandy soils (5 mg As/kg soil dw). A comparison of the SQC derived in this work with ecotoxicologically based soilquality values from Canada, Denmark, the Netherlands, and the United States shows an average value of 16 mg As/kg, with a range between 5 and 34 mg/kg. The variations in the soil quality values are mainly due to differences in the derivation approaches.

Conclusions and Outlook

The concept applied is considered suitable for the derivation of SQC designed to protect terrestrial communities against direct effects of substances in soils. Therefore, its use is planned to derive SQC for other environmentally relevant substances. In addition to compensation factors, statistical methods should be taken into account to compensate for risks which cannot be quantified. Furthermore, there is the need for an assessment of indirect effects of soil contaminants on birds and mammals.     

Wassergefährdungspotenzial nativer Öle und Fette: Berücksichtigung physikalischer Effekte

Aim and Background

Varying interpretations of the hazard potential of native oils and fats for aquatic ecosystems have led to conflicting international and national regulations. Background is the different consideration of physical effects. This study aimed at compiling published data on behaviour and effects of native oils and fats in water, hereby providing a basis for discussion on adequate classification of these substances.

Results

According to scientific data, physical effects may significantly contribute to the hazard potential of native oils and fats. This is especially important in risk assessment of spills, e.g. in the case of accidents. Basically, these effects are the same in marine and freshwater environments; the latter may even be regarded as worst-case situations with respect to physical effects.

Recommendations

Based on these facts, the German classification of native oils and their derivates as ‘not hazardous to waters’ according e.g. to § 19g of the Water Resources Act and § 4 of the Ordinance of Hazardous Substances should be revised. New criteria need to be incorporated into the evaluation procedure to allow an adequate assessment of these substances regarding physical effects.     

Untersuchungen zum ökotoxikologischen Schädigungspotenzial und Erosionsrisiko von kontaminierten Sedimenten in staugeregelten Flüssen

Particle-bound pollutants accumulate in river-bottom sediments, a process which results in a significant decrease in the ecotoxicological availability of toxicants for the majority of aquatic organisms. Under normal hydrologic conditions, the release of contaminants from bottom sediments is usually of minor importance. In contrast, flood events may remobilize highly contaminated sediments via in-stream erosion. The objective of this study was to develop a combined ecotoxicological and hydraulic approach to elucidate the ecotoxicological implications associated with the risk of erosion of contaminated sediments. This integrated strategy was applied to the lock-regulated Neckar river in Southern Germany. Both the bottom-sediment cores and suspended matter from two intensive flood events were investigated. Sediment samples below an erosional unconformity showed a sharp increase in the ecotoxicological load. Moreover, it was found that major flood events (HQ₅ and higher) could possibly erode even very old, well-consolidated and highlycontaminated sediments. The suspended matter of the high discharge events investigated (return periods of 15 to 20 years) exerted significantly higher cytotoxicity and mutagenicity than a moderate flood with a 1-year return period. These findings support the conclusion that the observed ecotoxicological effects during major floods may at least in part be due to the in-stream erosion of highly contaminated bottom sediments.     

Schwermetalle in Regenwürmern Baden-Württembergs

Goal and Scope

The heavy metal burden of the soil and of earthworms from representative long-term forest observation plots has been measured since 1984 as one component of the media-embracing environmental monitoring network of the State of Baden-Wuerttemberg. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis

Methods

So-called characteristic curves for the metals Cd, Cu, Ni, Pb, and Zn were developed for the assessment. Earthworm toxicity data and background values in soil served as criteria. This procedure facilitates a comparative assessment of different pollutants. The mobility of the metals, which greatly influences their bioavailability and toxicity, was taken into account for the effects assessment.

Results and Conclusion

Besides inventorying the heavy metals (Part 1), the question of threshold values for toxic reactions as well as for accumulation was raised. The metal concentrations were assessed in the soil with regard to its habitat function. The ecotoxicological assessment revealed that the heavy metal burden of the investigated plots lies within the background- or precautionary range, well below the screening value established here to indicate the effect threshold in earthworms. This result means that a pollution of the forest observation plots with the metals cadmium, copper, lead, nickel, and zinc is low or absent. Only the distribution of the lead content is centered slightly above background (but clearly below the toxicity threshold). This slight lead burden of the soil of the observation plots can be explained by emissions from motor vehicles. Investigations at sites that are contaminated with either chromium or copper or cadmium showed that an accumulation of these metals in the body of the worms can be observed only above a threshold concentration of several hundred micrograms of mobile metal per kilogram in the upper layer of the soil.

Recommendations and Perspectives

The hitherto unknown threshold values for the accumulation in the body of the earthworm should be statistically validated and extended to other elements. Further research is needed in order to build a well founded basis for the ecotoxicological assessment of soil pollution. Acute and chronic earthworm effect thresholds are neither available yet for arsenic, cobalt, and mercury nor for some other elements occurring less frequently as soil pollutants. Background values depending on the kind of rock have been measured so far for total chromium only. They are lacking for the more toxic chromium (VI) which is a frequent soil pollutant but naturally occurs in traces only.     

Identifizierung toxischer Verbindungen in Sedimenten: Ansätze zur Integration von Wirkung und Bioverfügbarkeit

Sediments play an important role for aquatic ecosystem functions. However, they also act as sink, storage and source of lipophilic toxicants and metals. Effect-directed analysis (EDA) is a powerful tool to identify compounds causing adverse effects. In order to avoid misinterpretations and biased prioritization bioavailability needs to be considered together with effects. Bioavailability is a complex process finally resulting in the transfer of a so far particle bound molecule to the target location within the organism where it causes an effect. In order to operationalize this concept for EDA it can be divided into several partial processes. These include desorption from sediments and thus bioaccessibility, equilibrium partitioning of desorbable compounds between sediment, water and organisms driven by activity, and toxicological bioavailability as a result of toxicokinetics including resorption, transport, metabolization and excretion. Bioaccessibility is based on desorption kinetics and can be simulated with mild extraction methods e.?g. using TENAX. Equilibrium partitioning can be simulated with partition-based dosing techniques. First results with these approaches indicate that consideration of bioavailability increases the significance of polar sediment-associated toxicants relative to classical non-polar contaminants such as polycyclic aromatic hydrocarbons.     

Morphologische Parameter als Biomarker in der Ökotoxikologie – natürliche und schadstoffinduzierte Variabilität

Background Ecotoxicology utilizes alterations of biological parameters of organisms as biomarkers of toxic exposure or effects. In environmental monitoring, biomarkers function as sensitive indicators of chemical pollution or as early warning signal of late effects Aim The pre-requisite for using a biological parameter as biomarker is the ability to unequivocally distinguish between the natural or normal and the induced or abnormal expression of the marker. This article discusses problems in discriminating between the normal and induce state, using morphological biomarkers as an example. Results and Discussion Morphological and/or anatomical parameters are intuitively considered to be rather invariable. This article shows for the example of gonad morphology of fish that this expectation is not always correct, but that morphological markers may display pronounced baseline variability. The reasons for this variability are often not understood. This is limiting the utility and interpretation of the biomarker response, in particular when organisms are not only exposed to chemical but to multiple stressors. Outlook The problem of discriminating between natural and induced variability of biomarkers is of particular relevance in low dose exposure scenarios, when stressors other than toxic chemicals may confound the toxicant-induced changes of the biomarker status. To better handle this problem and to be able to distinguish between adaptive and adverse changes, ecotoxicology has to set out for improved understanding of the phenotypic plasticity of organisms and genotypes,     

Abschätzung des Beitrages kommunaler Kläranlagen an Schadstoffkonzentrationen in Oberflächengewässern

A number of products, such as washing agents or pharmaceuticals, enter the hydrosphere mainly with municipal wastewater. In this case the predicted environmental concentrations (PEC) of substances are largely determined by their elimination in municipal wastewater treatment plants and by the dilution ratio of wastewater in the rivers. In this article some rough estimates of the wastewater ratio in German rivers are presented and as a starting point for a more complex model for calculating the PEC more exactly, data on the fluctuation of river flow rates are shown.     

Schwermetalle in Regenwürmern Baden-Württembergs

Goal and Scope

Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis.

Methods

At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda.

Results and Conclusion

The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor internationally. Time trend studies have been available for lead and cadmium since 1985/86, and for zinc since 1987. The studies show a steady decrease of the heavy metals on a state-wide average and especially in the ‘Odenwald’ and ‘Black Forest’ hills with their formerly highly polluted earthworm habitats. Today, the level of these metals in the earthworms is low with few exceptions. This holds true for other heavy metals as well.

Recommendations and Perspectives

The state-wide decreasing very low heavy metal burden of forest observation plots far from known emission sources can be considered a success of air pollution abatement measures. Because of the ongoing atmospheric deposition of heavy metals, regular observation should continue in order to estimate time trends and to recommend the reduction of emissions when precautionary values (part 2) are exceeded.     

Bewertungsmaßstäbe zur Beurteilung von Schadstoffbelastungen in Böden anhand der Bioverfügbarkeit

Until now, assessment of contaminated sites is based on variable protection goals, whereby total contents and in part mobile contents are considered. Due to interactions of pollutants in soil and bound residues, total contents do not reflect the actual risk. In contrast an investigation based on availability/bioavailability of contaminants would enable a harmonization of the protection-goal-based evaluation and a closer-to-reality risk assessment for the individual location.     

Treibhausgas-Emissionen zukünftiger Erdgas-Bereitstellung für Deutschland

Background

Natural gas makes a significant contribution to the current energy supply and its importance, in relation to both the German and worldwide energy supplies, will increase further in decades to come. In addition to its high degree of efficiency, the low level of direct GHG combustion emissions is also an advantageous factor. However, around 90% of natural gas is methane (CH₄), which is the second most significant GHG due to its high greenhouse potential (21 times higher than CO₂). Therefore, high levels of direct gas losses of natural gas in its production, processing, transport and distribution could neutralise its low emission advantages. This is particularly apparent when considering the growing distances between production and use, the demanding production processes and the upcoming worldwide market for LNG (liquefied natural gas).

Aim

This paper aims to analyse and illustrate the future GHG emissions of the whole process chain of natural gas (indirect emissions) to be supplied to the German border over the next 2 decades. This should allow the comparison of total GHG emissions (indirect and direct) of natural gas with the GHG emissions of other fossil fuels. By considering likely changes in gas origin as well as dynamic changes in the infrastructure and technology of gas production, processing and transport until 2030, all relevant factors are included. The study focuses on the emissions of Russian natural gas as Russia is already, and will be in the future, the most important gas supplier to the German and European gas markets.

Results and Discussion

The analysis illustrates a significant change in the gas supply over the next two decades. The EU Gas Fields are in decline and it is predicted that these will run dry. In parallel the share of Russian and Norwegian natural gas, and also the levels of LNG production (e.g. from Algeria or Egypt), will increase. Although the potential for GHG emissions tends to grow as a result of greater transport distances and demanding production and processing activities, high investment in necessary mitigation options (e.g. through replacing older and inefficient technology; updating to state-of-the-art technology) may neutralise the increase. The overall result of these counteracting trends will be to decrease GHG emissions, in a range of around 12% per TJ of direct emissions of natural gas, depending on the level of investment in the modernisation of the Russian gas infrastructure and the improvements of the LNG process. In the two given scenarios the indirect emissions of the natural gas used in Germany will decrease from about 23 million t CO₂-eq (2005) to 19.5 or 17.6 million t CO₂-eq in the year 2030. In spite of a significant higher gas consumption the emissions are reduced in the first scenario due to technical modifications. In the second scenario the emission reduction is based on the lower gas consumption.

Conclusions

At present, the indirect GHG emissions of the natural gas process chain are comparable to the indirect emissions produced by oil and coal. The emission trend of the natural gas process chain will markedly decrease if the mitigation options are followed consistently. However, in order to ensure the long-term security of natural gas supply for future decades, a high level of investment is essential. With regard to future emissions, the best available technology and, therefore, that which is most economically feasible in the long term, should be used. Under these conditions natural gas — as the fossil fuel with the lowest levels of GHG emissions — can play a major role in the transition to a renewable energy supply for the future.