Effect of formaldehyde on biofilm activity and morphology in an ultracompact biofilm reactor for carbonaceous wastewater treatment.

The effects of formaldehyde on biofilm morphology and biomass activity were investigated in an ultracompact biofilm reactor (UCBR) for carbonaceous wastewater treatment. The wastewater contained a fixed amount of glucose (with a chemical oxygen demand concentration of 600 mg/L) and an increasing concentration of formaldehyde (ranging from 21.4 to 271.1 mg/L). An influent formaldehyde concentration higher than 75 mg/L could facilitate filamentous growth (on biofilm) control and lead to a higher biofilm density, which is desirable as it enhanced the UCBR performance stability. However, at an influent formaldehyde concentration higher than 214.4 mg/L, biomass production was inhibited and deteriorations of biofilm morphology and biomass activity were observed. This study showed that it was desirable to maintain an influent formaldehyde concentration lower than 202.2 mg/L, as this concentration could achieve a good biofilm morphology while not inhibiting its microbial activity.     

Some pharmacokinetic aspects of PCDDs and PCDFs in mammals after administration of a fly ash extract from a municipal incinerator

Fly ash extracts were fed to male hamster (single dose), male rat (single dose and multiple dose), pregnant and lactating female rat (multiple dose). The retention of four isomers, 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PnCDD and 2,3,4,7,8-PnCDF, was studied in the liver of the adults, foetuses and liver of the sucklings.

Liver retention was structure dependent and different for both species. Transportation of the isomers via the mother milk was 50–100 times more effective than via the placenta.

After a single intravenous dose of fly ash extract to male rats the elimination of these four isomers was studied in the liver, during a period of 10 days. Elimination rates for 2,3,7,8-TCDD, 1,2,3,7,8-PnCDD and 2,3,4,7,8-PnCDF were in the same range. Pharmacokinetic calculations were done on both tetra congeners, to obtain information about the validity of the published K_e values in the multiple dose experiments with male rats.

For 2,3,7,8-TCDF the K_e value was applicable, but for 2,3,7,8-TCDD the validity of the K_e could not be determined.     

Is metal extraction by Arabidopsis halleri related to exchangeable metal rates in soils amended with different metal-bearing solids?

Metals are associated to various constituents in polluted soils, and their availability is closely related to their chemical speciation. Studies on relations between metal extraction efficiency by hyperaccumulators and location of metals with respect to soil constituents are scarce. In this study. we investigate the relationship between metal extraction by Arabidopsis halleri and the exchangeable metals from substrates amended with various metal-bearing solids collected in the vicinity of a Zn smelter complex. These consisted of fresh and decomposing organic matter, the soil clay fraction, and two types of waste slags. ZnSO4 was also used as metal-bearing solid. Each was mixed with an unpolluted soil to produce two types of substrate, one moderately polluted and the other highly polluted. Total Zinc, Cd, Cu, and Pb were measured in substrates and in roots and shoots of A. halleri. Analysis of 0.01 M CaCl2 exchangeable metals in each substrate was performed before and after plant growth. The results showed different concentrations of exchangeable metals after plant growth, depending on the nature of the metal-bearing solids. In the ZnSO4 soil substrate, the proportion of exchangeable Zn decreased after plant growth, whilst it increased significantly on substrates amended with the two waste slags. For the other substrates, exchangeable Zn was not significantly different before and after plant growth. The same trend was observed for Cd. In the case of Cu, exchangeable rates increased in all substrates. The results were discussed according to the characteristics of the metal-bearing solids and to the metal-uptake strategy of A. halleri.     

Ökotoxikologische und humantoxikologische Risikobewertung PAK-belasteter Böden vor und nach biologischer Behandlung

The goal of the present work is to assess the adverse effects of soil bound polycyclic aromatic hydrocarbons (PAH) which remain in soils after biological remediation. We focus on risk assessment for mammalian species with respect to the oral uptake of contaminated soil particles and compare the results of a biomarker test with those of an ecotoxicological assay, the bioluminescence inhibition test withVibrio fischeri. As a biomarker effect in mammals, we determined the liver microsomal cytochrome P450 enzyme CYP1A1 which is induced by PAH in exposed rats. After biological soil treatment, different amounts of PAH remain in the soil depending on the soil properties and initial pollutant composition. Particularly, higher condensated PAH resists biological treatment due to its hydrophobicity. In addition, high amounts of organic carbon in the soils affect remediation efficiency. In the bioluminescence inhibition test, eluates of all biologically treated soils studied do not reveal any or only low inhibitory effects. In contrast, the oral uptake of biologically treated contaminated soils leads to induction levels for CYP1A1 similar to those in the untreated samples. A good correlation is obtained between CYP1A1 levels and the amount of 5 and 6-ring PAH in the soil samples. The main result is that the remediation efficiency determined by the luminescence test is not reflected by the biomarker test, a finding which indicates the high bioavailability of residual PAH in soils. Consequently, new criteria for human risk assessment can be delineated.     

Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Delayed reporting reduces the usefulness of such data for nature conservation where timely information about animal movements is required. To counter this problem, we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (based on radial and angular velocity calculated from fixes) allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data. Automating the detection of both excursions and home-range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal. The automated analysis, interpretation, and communication of satellite-tag and other ecological data offer clear benefits to nature conservation research and practice.