Anaerobic degradation of 2,4,5-trichlorophenoxyacetic acid by enrichment cultures from freshwater sediments.

The anaerobic biodegradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was investigated using enrichment cultures from freshwater sediments at two different sites in the region of Halle, central Germany. 2,4,5-T and different organic acids or hydrogen were added as possible electron acceptor and electron donors, respectively. The primary enrichment cultures from Saale river sediment completely degraded 2,4,5-T to 3-chlorophenol (3-CP) (major product) and 3,4-dichlorophenol (3,4-DCP) during a 28-day incubation period.

Molecularly Imprinted Polymer Materials as Selective Recognition Sorbents for Explosives: A Review.

Explosives are of significant interest to homeland security departments and forensic investigations. Fast, sensitive and selective detection of these chemicals is of great concern for security purposes as well as for triage and decontamination in contaminated areas. To this end, selective sorbents with fast binding kinetics and high binding capacity, either in combination with a sensor transducer or a sampling/sample-preparation method, are required.

Development of a multi-VOC reference material for quality assurance in materials emission testing.

Emission test chamber measurement is necessary to proof building materials as sources of volatile organic compounds (VOCs). The results of such measurements are used to evaluate materials and label them according to their potential to emit harmful substances, polluting indoor air. If only labelled materials were installed indoors, this would improve indoor air quality and prevent negative impacts on human health.

Synthesis of novel palladium(0) nanocatalysts by microorganisms from heavy-metal-influenced high-alpine sites for dehalogenation of polychlorinated dioxins.

In a search for new aqueous-phase systems for catalyzing reactions of environmental and industrial importance, we prepared novel biogenerated palladium (Pd) nanocatalysts using a "green" approach based on microorganisms isolated from high-alpine sites naturally impacted by heavy metals. Bacteria and fungi were enriched and isolated from serpentinite-influenced ponds (Totalp region, Parsenn, near Davos, Graubünden, Switzerland). Effects on growth dynamics were monitored using an automated assay in 96-well microtiter plates, which allowed for simultaneous cultivation and on-line analysis of Pd(II)- and Ni(II)-mediated growth inhibition.

Identification of plant metabolites of environmental contaminants by UPLC-QToF-MS: the in vitro metabolism of triclosan in horseradish.

Plants can extensively transform contaminants after uptake through phase I and phase II metabolism to a large diversity of products. UPLC-QToF-MS was used to detect and identify metabolites of the bacteriostatic agent triclosan in a horseradish hairy root culture. Thirty-three metabolites of triclosan were recognized by a stepwise approach of mass defect filtering, multivariate data analysis, and isotope pattern filtering from a data set of several thousands of signals in the exposed culture.

Development of a material with reproducible emission of selected volatile organic compounds - μ-Chamber study.

Volatile organic compounds (VOCs) found indoors have the potential to affect human health. Typical sources include building materials, furnishings, cleaning agents, etc. To address this risk, chemical emission testing is used to assess the potential of different materials to pollute indoor air.

Metabolization of the bacteriostatic agent triclosan in edible plants and its consequences for plant uptake assessment.

Persistent environmental contaminants may enter agricultural fields via the application of sewage sludge, by irrigation with treated municipal wastewater or by manuring. It has been shown that such contaminants can be incorporated into crop plants. The metabolism of the bacteriostatic agents triclocarban, triclosan, and its transformation product methyl triclosan was investigated after their uptake into carrot cell cultures.

Uptake of galaxolide, tonalide, and triclosan by carrot, barley, and meadow fescue plants.

Many xenobiotics entering wastewater treatment plants are known to be persistent during wastewater treatment and tend to adsorb to sewage sludge. The application of sewage sludge as fertilizer in agriculture may pose the risk of an incorporation of xenobiotics in the cultivated plants and, finally, an inclusion into the food chain. This study was performed to investigate the uptake of common sewage sludge contaminants, galaxolide, tonalide, and triclosan, by plants used for human consumption and livestock feeding.

Remobilization of pentavalent antimony and vanadium from a granular iron hydroxide material--a comparative study of different leaching systems.

The remobilization of antimony and vanadium from previously loaded commercial granular ferric-hydroxide GEH material (intended for water treatment) was examined by using a sequential extraction procedure and three different leaching systems to evaluate their physicochemical mobility and potential availability under different simulated environmental conditions. A classical batch extraction, an extraction cell (EC) and rotating-coiled columns (RCC) were used as extraction systems. For each system it could be shown that the content of ion-exchangeable antimony and vanadium in previously loaded material is negligible (<1.

Analysis of brominated flame retardants in house dust.

The main objective of this study was to create a robust analytical method to analyse the flame retardants decabromodiphenylether (BDE-209), hexabromocyclododecane (HBCD), and tetrabromobisphenol-A (TBBPA) in house dust in order to estimate the degree of contamination of indoor environment. A liquid chromatography method equipped with a UV-detector and electro spray-tandem mass spectrometry was used to achieve this result. Applying an external calibration for BDE-209, an internal calibration for TBBPA, and a standard addition method for HBCD low limits of quantification were obtained.

Development and application of dynamic air chambers for measurement of volatilization fluxes of benzene and MTBE from constructed wetlands planted with common reed.

Phytoremediation of industrially contaminated groundwater has been a proven technique for several decades. However, mass balances of contaminants are often focused in laboratory investigations. The evaluation of the transfer of volatile organic compounds (VOCs) under field conditions from the saturated and vadose soil zone into the atmosphere, directly or via plants, is rarely part of the research scope.

Nature of DNA-bound fatty acids in Pseudomonas aurantiaca.

The existence of Pseudomonas aurantiaca DNA-bound fatty acids and lipids is presented in this work. The isolation of DNA was carried out by two different procedures, namely, phenol and detergent-based phenol isolation in order to prove the presence of DNA-bound lipids. The lipid content of DNA is expressed in terms of fatty acid profile.

Development of an integrative passive sampler for the monitoring of organic water pollutants.

The development of convenient and competitive devices and methods for monitoring of organic pollutants in the aquatic environment is of increasing interest. An integrative passive sampling system has been developed which consists of a solid poly(dimethylsiloxane) (PDMS) material (tube or rod), acting as hydrophobic organic receiving phase, enclosed in a water-filled or an air-filled low-density polyethylene (LDPE) membrane tubing. These samplers enable the direct analysis of the pollutants accumulated during exposure in the receiving phase by thermodesorption-GC/MS, avoiding expensive sample preparation and cleanups.

Reductive dehalogenation of chlorinated dioxins by an anaerobic bacterium.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs and PCDFs) are among the most notorious environmental pollutants. Some congeners, particularly those with lateral chlorine substitutions at positions 2, 3, 7 and 8, are extremely toxic and carcinogenic to humans. One particularly promising mechanism for the detoxification of PCDDs and PCDFs is microbial reductive dechlorination.