Vergleich ausgewählter Elutionsverfahren zur Beurteilung der Mobilität von Metallen

Comparison of Selected Elution Procedures for the Valuation of the Mobility of Metals from Sediment and Sewage Sludge Several methods of extraction are generally used to evaluate environmental or ecological toxicity and deposition of waste material. In this paper, the application of the German standard methods DIN 38414-S7, DIN 38414-S4, pH_stat method, “Schweizer method” (elution test, Switzerland), and some variants of the pH_stat method on two very different samples are described. A rudimental sediment and a municipal sewage sludge are chosen as sample materials. The metal contents of extract solutions are determined by ICP-OES. The results of the DIN-S4 extractions depend definitely on the mechanic way of movement, i.e. the amount of heavy metals which are mobilized out of the samples differs considerably. In fact, DIN-S7 in combination with DIN-S4 is not sufficient to estimate the mobility of heavy metals. Solid samples should only be evaluated by applying a combination of several methods of extraction. The usefulness of the pH_stat method for an evaluation is discussed.     

TOC-Bestimmung in Schlämmen,Sedimenten und Schwebstoffen — Beschreibung des Verfahrens und begleitender Qualitätssicherungsmaßnahmen Determination of TOC in Sludge,Sediment and Suspended Solids — Description of the Analytical Procedure and Accompanying Quality Control Procedures

The total organic carbon (TOC) is calculated by subtracting the inorganic carbon (IC) from the total carbon (TC). For TC determination, the carbon in a sample is completely converted to CO₂ by decomposition/combustion in an oxygen stream. To determine IC, inorganic carbon (carbonate) is liberated by adding acid and by heating in an oxygen stream. In both cases, CO₂ is quantified by infrared spectrometry. To gain reliable and reproducable results for sludge, sediment and suspended solids, at least the following conditions have to be met: particle size has to be smaller than 200 μm; weightout has to be selected in such a way, that the signal area is not below and the signal maximum is not above specific instrument dependent parameters; combustion/decomposition has to be complete (TC: ≥ 1300 °C, no soot) and rules for analytical quality assurance must be followed. The TC quantification of calcium carbonate is used for system calibration. Daily working procedures include calibration checks by mean control charts for TC determination of calcium carbonate and IC determination of sodium carbonate as well as for control sediment TC and IC quantifications.     

Historische Entwicklung einer Sedimentbelastung: Gedächtnis einer Industrieregion Historical Trends of Sediment Loads: Memory of an Industrial Region

The chronologies are shown of sediment load on the banks of a river of the Ruhr district (Lippe) with radionuclides of radium, lead and cesium and preliminary chemical measurements for lead, zinc, arsenic, mercury, cadmium, barium, PAHs, PCDDs, PCDFs, PCBs, TOC, AOX and EOX. A new method of dating is developed and proved, which is especially suitable for rivers with radioactivity from coal mines. The method improves the well-known excess-²¹⁰Pb-dating for the use with rivers in industrial regions and allows the preparation of load histories (chronologies). Conclusions are made on the historical trend of emissions in the region from the trend of the sediment load of known age and regular sedimentation without perturbation.     

Eignung mikrobieller Biotests für gebundene Schadstoffe Suitability of Microbial Bioassays for Bound Contaminants

Toxicity of soil spiked with water soluble and insoluble contaminants was assessed with bacteria. Three bioassays were used with common soil bacteria. Water soluble fractions from the soils were estimated in microtiterplates via dehydrogenase activity of B. cereus and growth of P. putida. A new method was developed using B. cereus to include effects of soil particles with bound contaminants. As contaminants p-nitrophenol and 2-naphthol were tested in these systems. Results indicated that the concentration of the contaminants in the soil solution is determined by soil properties. Toxicity of water soluble fractions was not only a result of the toxicant's concentration but further modified by soluble components of the soils. It is not possible to assess soil pollution from toxicity of the water soluble fraction in general, because unknown factors of the soluble soil fraction can influence toxicity greatly. The newly developed contact bioassay with B. cereus showed clearly higher toxicity of 2-naphthol estimated in soil suspension than did the comparable test system with the same bacteria using water soluble fractions only. The results stress the importance of including soil particles into bioassay procedures. It was shown that also water insoluble, bound contaminants can act as toxicants. For an estimation of toxicity under conditions more relevant for the environment, the suggested test system can provide useful information to bioavailability of bound contaminants.     

Kurzzeit-Toxizitätstests zur Messung der Toxizität von Chemikalien gegenüber Belebtschlamm

Short-term Toxicity Tests for the Measurement of Toxicity of Chemicals Towards Activated Sludge. To avoid severe damage to the activated sludge of a wastewater treatment plant it is necessary to control the sludge activity by means of biological test systems. Especially the short-term respiration assay and the dehydrogenase assay with resazurin as a redox-dye seem to be appropriate for this monitoring program. The practical performance of both test systems was optimized in some essential points. With the help of several reference substances both monitoring systems were tested for practical use as short-term toxicity tests. The results of the investigations showed that the inhibitory concentrations measured in both test systems were partially very different. In monitoring experiments with laboratory-scale wastewater treatment plants it could be shown that a positive correlation between respiration activity and dehydrogenase activity is not always given. Furthermore, a pH-dependent toxicity could be demonstrated for several substituted phenols.     

Identifizierung ausgewählter Pestizide im Wasser mit Hilfe eines screening-Systems auf Grundlage der Dünnschichtchromatographie

After their extraction from water, 16 water pollutants of the families of triazines, urea herbicides, phenoxycarboxylic acids and organochlorine and organophosphorus insecticides are separated and identified by thin-layer chromatography. The method is suitable for routine analyses and was tested on model waters, inclusive of water from the Elbe river. The rate of redetection is up to 80%, the detection limit is at 0.5… 2 μg of the individual pollutants.     

Verhalten ausgewählter Arzneimittel bei der künstlichen Grundwasseranreicherung – Eliminierung und Effekte auf die mikrobielle Besiedlung

Behaviour of Some Pharmaceuticals during Artificial Groundwater Recharge – Elimination and Effects on Microbiology The behaviour of bezafibrate, carbamazepine, clofibric acid, diclofenac, ibuprofen, and gemfibrozil during artificial groundwater recharge was investigated with different test systems simulating field conditions. The given concentrations of the pharmaceuticals were 100 μg/L in the influent of the systems. Concentrations in the influent as well as in the effluent were measured by GC‐MS. These column experiments indicated a significant elimination of bezafibrate, diclofenac, and ibuprofen (60 to 80%) during slow sand filtration. The results showed a moderate elimination of clofibric acid and gemfibrozil (40 to 60%) but a rather low elimination of carbamazepine (<40%). The adaptation times until the elimination processes started were about 5 days. Only the elimination of carbamazepine needed a lag phase up to 17 days. Additional column experiments with groundwater model systems indicated a high persistence of pharmaceuticals under aerobic and anaerobic groundwater conditions. The elimination was less than 20%. Only diclofenac was eliminated with rates between 60% and 80% in aerobic systems and between 40% and 60% in anaerobic systems. Analysis of eubacterial 16S‐rDNA by PCR and DGGE demonstrated changes in the microbial community structure in slow sand filters after application of pharmaceuticals. Adaptation processes may cause these changes, e.g. the appearance or disappearance of single species. Also differences between the populations of water and of the solid phase in slow sand filters could be demonstrated by DGGE pattern.     

Adjustment of a Formulated Sediment for Sediment Testing with Caenorhabditis elegans (Nematoda)

The OECD soil, which is standardised for use in the sediment toxicity with the midge Chironomus riparius revealed inhibition of the nematode Caenorhabditis elegans in body growth length and egg production of 41.0% and 84%, respectively. 18 formulated sediments were tested to optimise the sediment composition for growth and reproduction of C. elegans. Their components were chosen to simulate native sediments, whereby different quantities and different clay minerals were tested. The mixture that we found to be optimal in our experiments consisted of 5% sphagnum peat, 70% calcitic sand, 0.5% dolomite limestone, 4.5% iron(III) oxide, and a clay combination of 1.5% chlorite and 18.5% aluminium(III) oxide. When applying this mixture to C. riparius, the new formulated sediment improved also growth in comparison to the OECD sediment.     

UV-Derivativ-Spektren zur Vorabschätzung des Gehaltes von polycyclischen aromatischen Kohlenwasserstoffen in Schwebstoffen und Sedimenten der Gewässer Derivative UV Spectra for Estimating the Contents of Polycyclic Aromatic Hydrocarbons in Suspended Solids and Sediments of Waters

By means of UV spectra of cyclohexane extracts from aquatic sediments it is possible to distinguish: “normal” mineral oil aromatics (e. g. of the middle distillation fraction), used oils, and highboiling raffinates, tar oils, and — as representative of aromatics listed in the German drinking water ordinance — fluoranthene. Starting with less selective extractants and the basic UV spectra, it is shown that spectra of higher orders frequently allow a quantitative determination of fluoranthene. If it is justified to assume a constant conversion factor, the result of the measurement can be used to calculate the contents of the whole group of aromatics listed in the German drinking water ordinance. A comparison with other methods (HPLC etc.) and with results from other laboratories showed good agreement. Finally, the diagnostic capacity (fingerprint) of derived spectra is pointed out.     

Anreicherung und Verteilung von Schwermetallen und anderen Elementen in Oberflächensedimenten der Berliner Gewässer und ihres Umlands Enrichment and Distribution of Heavy Metals and Other Elements in Surface Sediments of Berlin Waters (Germany) and their Surroundings

For a wide variety of substances aquatic systems are the medium of origin, or sinks in a longer or shorter lasting stay or even in geological periods. For surface sediments of Berlin waters and their surroundings this paper describes the enrichment and distribution of heavy metals (SM), which have a high priority under international aspects and a marked capability to geoaccumulation. From the 25 metals investigated Hg, Pb, Cu, Cd and Zn are of anthropogenic origin, all others are of geochemical provenience and correspond to background values. Some metals (Hg, Cd, Ni, Co, Cu, Cr and Pb) have specific concentration profiles with increasing depth of water and sediment. The study of correlation of SM in sediments demonstrates generally a strong relation to macroelements and between some metals themselves.     

Trophieindikation in Fließgewässern mit Hilfe des TIM (Trophie‐Index Makrophyten) – Erprobung eines neu entwickelten Index im Inninger Bach

Indicating the Trophic State of Running Waters by Using TIM (Trophic Index of Macrophytes) – Exemplary Implementation of a New Index in the River Inninger Bach The river Inninger Bach represents the outflow of the lake Wörthsee (Bavaria). The mean pH of the calcareous river has a value of ca. 8 during the vegetation period, the mean conductivity is about 350 to 400 μS/cm. The macrophyte vegetation of the river course was mapped and the nutrient concentrations of both the water body and the sediment were measured. In every mapping section the Trophic Index of Macrophytes (TIM) was calculated. By cluster analysis the mapping sections were grouped into three zones which differed in macrophyte vegetation. These differences are not associated with varying nutrient concentrations but are mainly due to differences in the degree of shading. In spite of the characterisation of the lake Wörthsee as oligo‐mesotrophic the river Inninger Bach, which represents the outflow of the lake Wörthsee, is classified as meso‐eutrophic by the Trophic Index of Macrophytes TIM. The increased trophic state of the river compared to the lake is caused by the river Krebsbach, a small tributary flowing into the river Inninger Bach only a short stretch downstream of its outflow of the lake Wörthsee. The river Krebsbach shows a total phosphorus concentration of about 56 μg/L P. The input of diaspores of submerged macrophytes both from the oligo‐mesotrophic lake Wörthsee and the eutrophic river Krebsbach leads to a submerged vegetation comprising species with different optima in regard to the trophic situation. This is one of the main reasons why many values of the TIM have to be labeled as “not sure”.     

Assessment of Cyto‐ and Genotoxic Effects of a Variety of Chemicals Using Saccharomyces cerevisiae

Saccharomyces cerevisiae as the most simple eukaryotic organism is broadly accepted as a laboratory model organism. For the detection of potential toxic effects of pure compounds and complex composed samples like wastewater a miniaturised short‐term in vitro cyto‐ and genotoxicity screening assay was developed. The assay based on genetically modified S. cerevisiae cells deleted in the prominent drug efflux transporters Pdr5, Snq2, and Yor1 that facilitate pleiotropic drug resistance. The yeast strain devoid of these proteins that mediate the efflux of structurally diverse hydrophobic compounds exhibited an increased sensitivity to a variety of organic compounds. The DNA damage inducible RAD54 promoter fused to a yeast optimized derivative of the GFP (green fluorescent protein) gene from the jelly fish Aequorea victoria served as an indicator of DNA damage in this strain. Various pure compounds including the direct‐acting genotoxins methyl‐N‐nitro‐N‐nitrosoguanidine (MNNG), 4‐nitroquinoline‐N‐oxide (4‐NQO), methyl methanesulfonate (MMS) and hydroxyurea as well as the heavy metals cadmium and chromium(VI), the insecticide lindane and the central nervous system stimulant caffeine were tested exhibiting dose dependent induction of green fluorescence. All compounds were in parallel examined for chronic toxicity. A bioassay detecting simultaneously geno‐ and cytotoxic effects of potential toxicants in a single assay can be an important tool with a variety of applications in environmental monitoring and aquatic ecotoxicology. By partial automation and miniaturisation to microtitration scale this bioassay enables sensitive and fast biomonitoring for a multitude of samples.     

Elektrochemische Einschätzung des Oberflächenzustandes von Wasserreinigungskohlen

Electrochemical Characterization of the Surface of Activated Carbon Used in Water Treatment Plants. We tried to measure electrochemically those properties of activated carbons which are important for using them for water purification. A success was achieved with the electrochemical immersion potential U_i which is found to be a function of concentration of functional surface groups on the carbon surface. However, the expected direct proportionality for inert surfaces between BET surface area and amount of charge measured in recharge processes has not been observed.     

Maßnahmen zur Sanierung und Restaurierung des Elsterstausees bei Leipzig

Redevelopment and Restoration Measures for Lake Elsterstausee (Leipzig) Lake Elsterstausee is an artificial lake in the south of the town Leipzig. It was built in 1933, has an actual area of 50 ha, and an average depth of 2 m. Between 1970 and 1991, the lake was used for intensive fishery. Because of fish feeding and supplying the lake with highly nutrient loaded water from river Elster the waterbody was in a polytrophic state during this time. Secchi depth seldom exceeded 0.4 m, but pHvalues often exceeded 9. Therefore and because of ammonia concentrations between 1.5 and 4.0 mg/L fish kills often occured. Lake Elsterstausee had no usability as bath waterbody although it was orginally built for this purpose. In 1991, a complete programme for redevelopment and res-toration of the lake started. The main measures were the total exchange of trophic loaded water and the only supply with treated groundwater, the drastic decrease of fish populations – in 1991 140 tons of fish (90% carps) were removed from the lake, – the development of healthy wild fish populations and of a eutrophication diminishing food chain, and the development of a reed zone almost around the lake. The groundwater treatment was steadily improved between 1992 and 1996. Actually, the following optimized system works: Drained groundwater from the surface lignite mine Zwenkau (pH = 6.95) and percolating water from the heaps (pH = 3.01) are mixed in the proportion 1:1 after intensive aeration. The water flows through a ditch that is 1 600 m long and has a performance up to 300 m³/h. In the well-diversified ditch, up to 90% of the iron is removed by precipitation and filtration effect of submerged macrophytes and filamentous algae. In the same time, deacidification occurs primarily by sulfate reduction in the sediment. Meanwhile, the water has a pH of 4.64 immediately after mixing, this value enhances up to the end of the flowing distance to 7.3. Internal restoration of the lake started in November 1991 with the total removal of loaded water and of almost all carps and white fishes. In 1993, 4 000 carnivore fishes (zanders, pikes, welses) were given into the lake to keep white fish popu-lations on a low level. Additionally, every year between 5 and 7 kg of water fleas (Daphnia sp.) were added. By means of this initial biomanipulation, food chain in lake Elsterstausee was stabilized. As results of the above mentioned measures, nutrient content in the waterbody decreased and secchi depth increased steadily. Between 1991 and 1997, trophy degree according to Klapper developed from 5 (hypertrophic) to 3 (eutrophic).     

Beeinflussung der Enzymaktivität einer Protease durch Huminstoffe Influence of Humic Substances on the Activity of a Protease

This paper deals with the influence of different humic substances (HS) on the enzyme activity (EA) of the proteolytic enzyme pronase E. The EA was determined by analyzing the concentration of the amino acid valine hydrolyzed from caseine. For amino acid analysis, a flourescence detector was used after precolumn derivatization and HPLC-separation of the hydrolysis products. The data show that the presence of HS has no adverse effects on amino acid analysis. Based on this result, a decrease of EA was observed in the presence of HS acting as enzyme inhibitors. Clear inhibition effects could be seen for different fulvic acids (HO3 FA, FBR FA and FBR 1.0 FA) at concentrations of 150 mg/L. In case of FBI-2 FA, higher concentrations were necessary to decrease the EA significantly. At an inhibitor concentration of 1500 mg/L the EA was mostly found to be less than 50%. The standard deviations of the results don't allow a differentiation between the HS of different origin and treatment. Specifying HS according to their influence on EA has to remain uncertain. As shown in a kinetic study of the hydrolysis of L-Leucine-2-naphthylamide-hydrochloride, the inhibitor HO3 FA decreases the maximum velocity of the reaction but has no effect on the Michaelis constant. These results indicate that this HS acts as a noncompetitive inhibitor.     

Abschätzung und Beeinflussbarkeit der Arsenmobilität in kontaminierten Böden

Assessment and Modification of Arsenic Mobility in Contaminated Soil Arsenic concentration in the seepage of contaminated soils of an old tannery site is assessed using batch and column experiments. The effect of reducing conditions, pH, and ionic strength is also investigated. The iron oxide rich subsoil (C‐horizon) is the main source of groundwater pollution with arsenic. In this horizon, mobilization can increase as a result of reducing conditions upon periodical water saturation. Therefore, the potentially mobile arsenic is determined by a reductive dissolution of the poorly crystalline iron oxide fraction using 0.1 M ascorbic acid. Arsenic concentration can be reduced from 100 μg/L to below 20 μg/L by an increase of ionic strength (e.g. by a 0.01 M CaCl₂ solution). Arsenic contaminated soils should be limed regularly in order to maintain the highest possible calcium concentration in the soil solution.     

Retardation of Fin Regeneration in Freshwater Fish Oreochromis mossambicusby Zinc

Regeneration of partially amputated caudal fin was studied in freshwater fish Oreochromis mossambicus exposed to sublethal concentrations of zinc (5.0 mg L^—1 and 10.0 mg L^—1) under ambient laboratory conditions over a period of 20 days. Caudal fin regeneration was measured on 5th, 10th, 15th and 20th day of exposure and after amputation. Significant ( p < 0.05) retardation in fin regeneration was observed on day 5th and 10th in fish exposed to the nominal concentration of 5.0 mg L^—1 Zn, while retardation was found highly significant ( p < 0.01) at all the observations in 10.0 mg L^—1. The maximum inhibition in caudal fin regeneration (20.8 % and 24.3 %) was found during the initial observation at both of the concentrations (5.0 mg L^—1 and 10.0 mg L^—1) of zinc exposure. Later on the regeneration rate was almost as good as in the control group. Thus in this study fin regeneration was significantly inhibited at all time points following Zn exposure as a detrimental effect of Zn to fish. This study demonstrates that fish caudal fin regeneration is a simple assay, sensitive and easy to perform, and can serve as a model to determine the toxicity of pollutants in aquatic environment.     

Konzepte zur Mobilitätsabschätzung von Schadstoffen in Boden- und Abfallmaterialien

Concepts for the Evaluation of Contaminant Mobility in Soil and Waste Materials Elution tests (S4, pH_stat, and SDS test) are presented, enabling the evaluation of the mobility of hydrophilic/hydrophobic and inorganic/organic contaminants in soil and waste materials. While elution tests for estimation of the mobilization potential of hydrophilic substances are performed following the pH_stat method, for hydrophobic species surfactant-containing eluents are used. The individual parameters of the elution process are selected assuming a "worst-case" scenario. In principle, because of economic reasons, detailed analytical investigations should be preceded by relevant screening tests.     

Bestimmung von Umweltqualitätsnormen für potenziell gewässerrelevante Stoffe

With the Water Framework Directive (WFD) the European Commission (EC) is requested to define environmental quality standards for pollutants to protect aquatic life in surface waters. Quality standards have to be derived by a scientific risk assessment and should not be exceeded. The recommended quality standards are mainly based on long term toxicological tests with algae, crustaceans and fish. The lowest effect concentration is divided by an assessment factor between 10 and 1000, which considers the data quality and quantity. In this work funded by the German Länder Working Party on Water (Länderarbeitsgemeinschaft Wasser – LAWA) environmental quality standards for 40 considered relevant substances were derived for aquatic ecosystems. The data sheets cover the identification of the compounds, their behaviour in the environment (physical‐chemical properties, biotic and abiotic degradation, sorption, bioaccumulation), information about mode of action, uses, analytical determination and available quality criteria. Ecotoxicological effect concentrations for bacteria, algae, protozoa, aquatic plants, crustaceans, fish, amphibians, insects and molluscs are listed. For 17 of the 40 hazardous substances investigated, quality objectives above 1 μg/L were derived. For 12 substances the values were between 0.1 μg/L and 1 μg/L and for 5 substances lower than 0.1 μg/L. Incomplete ecotoxicological data sets of the remaining compounds do not allow the derivation of quality standards. Especially for drugs further ecotoxicological test results are needed.     

Die neue EG‐Wasserrahmenrichtlinie: Bewertung der chemischen und ökologischen Qualität von Oberflächengewässern

The New EC Framework Water Directive: Assessment of the Chemical and Ecological Status of Surface Waters The main objective of the draft EC Framework Water Directive is the good quality of all surface waters. The directive provides for an assessment of the chemical status of surface waters (EU‐wide valid environmental quality standards for approximately 30 priority substances) and a five‐stage ecological classification of waters, comprising the stages high, good, moderate, poor, and bad. The starting point for the assessment are the reference conditions, which are defined as corresponding to high water quality and characterising a water status with no significant anthropogenic impact. The reference sites in the various water body types are to be selected using hydromorphological and physico‐chemical parameters and subsequently characterised by means of biological parameters. For surface waters, three groups of characteristics are provided for, namely: 1. with priority the biology – in the case of surface waters – with the four elements phytoplankton, macrophytes/phytobenthos, benthic invertebrate fauna, and fish fauna; 2. supporting the hydromorphology, e.g. flowing waters with the three elements hydrological regime, river continuity, and morphological conditions and 3. supporting the physico‐chemical conditions with the three elements general conditions, specific synthetic pollutants, and specific non synthetic pollutants (other than the priority substances of the chemical status).