Reference materials for the monitoring of the aquatic environment--a review with special emphasis on organic priority pollutants

During recent years, the awareness of quality assurance and quality control in environmental analyses has constantly increased, especially due to the implementation of new guidelines and regulations at both the national and international level. Achieving comparable results by using certified reference materials is one of the primary concerns of the scientific community. As a result, there is a growing demand for certified reference materials to cover different matrices and pollutants. Moreover, these CRMs should be in close relationship to the determinants and target concentrations required by environmental bodies and European Directives as well. Supplementary information to this paper presents an inventory of reference materials available on the market from different suppliers against the priority pollutants listed in the Water Framework Directive. These CRMs cover matrices such as water, sediment and biota. The use of CRMs in relationship to appropriate analytical methods and relevant determinants is discussed and the need for matrix-CRMs, particularly for organic pollutants is emphasised. The use of proficiency testing schemes as an alternative for the lack of appropriate CRMs and future trends in the production of CRMs within the BCR framework are also discussed.     

Untersuchungen zur Eignung wildlebender Wanderratten (Rattus norvegicus) als Indikatoren der Schwermetallbelastung

Zusammenfassung  Durch die Quantifizierung von 12 chemischen Elementen im Organsystem von wildlebenden Ratten (Rattus norvegicus) aus dem Tierpark Zittau (Sachsen) sollte die Eignung dieser spezies als passiver Bioindikator untersucht werden. Neben der Ermittlung von sogenannten Hintergrund-konzentrationen standen insbesondere Fragen zur geschlechts-und altersspezifischen Akkumulation einzelner Elemente im Organsystem von Rattus norvegicus im Vordergrund. Spezifisch zeigten dabei einzelne Elemente unterschiedliche Affinit?ten zu den entsprechenden Geweben und Organen. Insbesondere die hierbei ermittelten geschlechts- und altersspezifischen Charakteristika einzelner Elemente macht eine detaillierte Ausarbeitung einer Beprobungsstrategie für den sp?teren Einsatz als passiver Bioindikator zwingend. Unter Berücksichtigung des durch die Berechnung des Body Burden (K?rperlast) im 2. Teil der Arbeit ermittelten typischen Verteilungsmusters einzelner Elemente ist Rattus norvegicus zum integrativen Monitoring-einsatz pr?destiniert. Bernd Markert ist Professor und Direktor des internationalen Hochschulinstitutes in Zittau und Lehrstuhlinhaber für Umweltverfahrenstechnik. Der Einsatz eines freilebenden, intelligenten ‘Sch?dlings’ für die Umweltüberwachung in der Bioindikation ergibt sich für ihn aus zwei zwingenden Gesichtspunkten: 1. Die Ratte als Nutztier (psychologisch/didaktischer Ansatz) 2. und als ‘missing link’ zwischen Wirbeltier und Mensch (bioindikativer/naturwissenschaftlicher Ansatz)     

Teilchenspuren in der Mikrotechnik

Wir danken M. Chlupka-Spohr, R. Handel, Chr. Trautmann und J. Vetter für wertvolle Anregungen zu diesem Bericht.     

Material flow analysis of RDF-production processes

The authors evaluate the possibilities of modifying the chemical characteristics of refuse-derived fuels (RDF) that are processed from residual household waste by mechanical operations to achieve and assure quality targets for relevant chemical concentrations, especially for heavy metals and chlorine. Quality assurance in the production of RDF demands that, together with an enrichment of the calorific value, highly toxic waste components are selectively separated and concentrated in a small stream to produce high yields of a relatively low polluted fuel. Based on the method of material flow analysis, a process evaluation is developed that considers the aspect of minimizing hazardous chemicals along with classical process data such as yield and product quality. Data on specific concentration of hazardous chemicals in waste components and their distribution in residual household waste as well as the results from large-scale test runs using different separation techniques demonstrate that mechanical operations alone are insufficient for separating hazardous chemicals. In the test runs, chemical compounds such as chlorine, cadmium and lead were often concentrated in the product. Even using optimized techniques, the ability to reduce hazards in the product is limited due to the distribution of the element concentration in the various components of the waste stream.     

Two Pilot Plant Reactors Designed for the In Situ Bioremediation of Chlorobenzene-contaminated Ground Water: Hydrogeological and Chemical Characteristics and Bacterial Consortia

The SAFIRA in situ pilot plant in Bitterfeld, Saxonia-Anhalt, Germany, currently serves as the test site for eight different in situ approaches to remediate anoxic chlorobenzene (CB)-contaminated ground water. Two reactors, both filled with originallignite-containing aquifer material, are designed for themicrobiological in situ remediation of the ground water bythe indigenous microbial consortia. In this study, thehydrogeological, chemical and microbiological conditions of theinflowing ground water and reactor filling material are presented,in order to establish the scientific basis for the start of thebioremediation process itself. The reactors were put intooperation in June 1999. In the following, inflow CB concentrationsin the ground water varied between 22 and 33 mg L^-1; achemical steady state for CB in both reactors was reachedafter 210 till 260 days operation time. The sediments werecolonized by high numbers of aerobic, iron-reducing anddenitrifying bacteria, as determined after 244 and 285 days ofoperation time. Furthermore, aerobic CB-degrading bacteria weredetected in all reactor zones. Comparative sequence analysis of16S rDNA gene clone libraries suggest the dominance of Proteobacteria (Comamonadaceae, Alcaligenaceae, Gallionella group, Acidithiobacillus) and members of theclass of low G+C gram-positive bacteria in the reactorsediments. In the inflowing ground water, sequences withphylogenetic affiliation to sulfate-reducing bacteria andsequences not affiliated with the known phyla of Bacteria, were found.     

Manganese-catalyzed degradation of phosphonic acids

The non-biodegradable and chemically very stable phosphonates are used in a variety of industrial applications including cooling waters, oil production and textile industry. We show here that they are degraded in the presence of Mn(II) and oxygen. The half-life for the reaction is 9 min near neutral pH. The presence of other cations such as Ca(II) and Zn(II) considerably slows down the reaction by competition with Mn(II) for the phosphonate. The reaction involves the oxidation of complexed Mn(II) by oxygen to Mn(III) and the subsequent oxidation of phosphonate by Mn(III) thus yielding two stable phosphonic acid breakdown products. The oxidation also proceeds in the presence of the mineral manganite (Mn(III)OOH), and yields the same breakdown products. The use of a newly developed chromatographic method revealed the presence of the breakdown products in wastewater. The results show that manganese-catalyzed oxidation might be an important pathway for phosphonate degradation in natural waters. Electronic Publication     

Trace elements in buried human bones: intra-population variability of Sr/Ca and Ba/Ca ratios – diet or diagenesis?

A comparative analysis of trace element data of human skeletal material from four archaeological sites is presented. We show that the state of histomorphological preservation of bone, which is a measurement for the degree of its diagenetic alteration, closely corresponds to the Sr/Ca and Ba/Ca ratios at an intra-population level. This study challenges the validity of dietary studies that are based on the presently used procedures for sample preparation and subsequent evaluation of strontium and barium concentrations.     

Miniaturization,genome size and the origin of functional constraints in the visual system of salamanders

During their evolution, many species of lungless salamanders (fam. Plethodontidae) have experienced a great increase in genome size and consequently in the size of their cells, including sensory receptors and neurons. In addition, some have become extremely miniaturized. The consequences of these events and the morphological compensatory processes are studied in the visual system of juvenile and adult salamanders.