Comparison of methods for leaching heavy metals from composts

This paper presents the determination of total iron, copper, zinc, chromium, nickel, lead, cadmium and mercury contents in the compost obtained from sorted municipal organic solid waste applying the following methods of sample mineralization: 40% hydrofluoric acid with preliminary incineration of a sample, a mixture of concentrated nitric(V) and chloric(VII) acids with preliminary incineration of organic matter and a mixture of nitric(V) and chloric(VII) acids without sample incineration. The speciation analysis of Tessier was used to estimate the bioavailability of the metals. Elution degrees of the mobile forms of the metals from the compost with 10% nitric(V) acid and 1 mol/dm(3) hydrochloric acid were compared. The contents of the elements in the eluates were determined applying atomic absorption spectrometry.     

The asteroid and comet impact hazard: risk assessment and mitigation options

The impact of extraterrestrial matter onto Earth is a continuous process. On average, some 50,000 tons of dust are delivered to our planet every year. While objects smaller than about 30 m mainly disintegrate in the Earth’s atmosphere, larger ones can penetrate through it and cause damage on the ground. When an object of hundreds of meters in diameter impacts an ocean, a tsunami is created that can devastate coastal cities. Further, if a km-sized object hit the Earth it would cause a global catastrophe due to the transport of enormous amounts of dust and vapour into the atmosphere resulting in a change in the Earth’s climate. This article gives an overview of the near-Earth asteroid and comet (near-Earth object-NEO) impact hazard and the NEO search programmes which are gathering important data on these objects. It also points out options for impact hazard mitigation by using deflection systems. It further discusses the critical constraints for NEO deflection strategies and systems as well as mitigation and evacuation costs and benefits. Recommendations are given for future activities to solve the NEO impact hazard problem.     

Driving forces from soil invertebrates to ecosystem functioning: the allometric perspective

The European soil policy is being focussed towards a more conscious and sustainable use of the soil, taking into account ecological, economical and societal dimensions. Living soil organisms are reliable bioindicators, as they provide the best reflection of the soil system, ecological services and ecosystem functioning therein. These most complex (bio)physical systems indicate, among others, the energy flow. Such processes can be described by rather simple power law relationships. In fact, the average body mass (dry weight) can be seen as an inherent species property, while population density is a much more flexible parameter reflecting ecosystem state. In this study, I review the interactions between these items in relation to feedbacks and conjectured relationships which can be seen as ecological networks. From this novel perspective, allometry can be used as an integrated measure for the anthropogenic influence on landscapes and related food webs. Allometry is, therefore, a perfect surrogate for land use intensity in modelling of field effects for restoration ecology and conservation biology. Robust correlations will be addressed between the density dependence of invertebrates and the ability of soil systems themselves to recover after disturbance. Quantitative indicators of soil community composition and related ecological services are proposed and their application for ecological risk assessment is illustrated.     

Multivariate data analysis of organochlorines and brominated flame retardants in Baltic Sea guillemot (Uria aalge) egg and muscle

Concentrations of organochlorines (OCs) and brominated flame-retardants (BFRs) were determined in guillemot (Uria aalge) eggs from the island of Stora Karls? in the Baltic Sea where 10 eggs/year were collected in the years 2000, 2001 and 2002. The dominating contaminant in egg was p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) with a geometric mean (GM) concentration of 18200 ng/g lipid weight (lw). The GM concentration in egg of hexabromocyclododecane (HBCD) of 140 ng/glw, was significantly higher than that of polybrominated diphenyl ether (summation operatorPBDE) of 77 ng/glw. For the evaluation of the data multivariate data analysis techniques namely principal components analysis (PCA), partial least squares regression (PLS), soft independent modelling of class analogy (SIMCA classification), and PLS discriminant analysis (PLS-DA), were used. We investigated whether the eggs' biological characteristics co-varied with egg concentrations of OCs and BFRs, and found e.g., significant negative correlations between egg weight and concentrations of HCB and p,p'-DDE. A PLS model with analyzed BFRs as the Y matrix and OCs as the X matrix could, with varying accuracy, calculate the concentrations of BFRs in the individual egg from their concentrations of OCs (e.g., R(2)Y of 0.89 for BDE47, and of 0.50 for HBCD). Lastly, we compared the contaminant concentrations in the eggs to those in previously analyzed pectoral muscles from adult guillemots from Stora Karls?, from the year 2000. A PLS-DA model, showed that some of the contaminants (e.g., HBCD and CB28) had significantly higher concentrations in egg than in muscle, although 7 of the 14 contaminants showed no difference in concentrations between the two matrices.     

Environmental pollutants in endangered vs. increasing subspecies of the lesser black-backed gull on the Norwegian Coast

Organochlorine (OC) residues were measured in eggs and blood of different subspecies of the lesser black-backed gull, Larus fuscus, on the Norwegian coast: a) increasing L. f. intermedius in the North Sea; b) endangered L. f. fuscus near the Arctic Circle; c) L. f. fuscus and greyish-mantled gulls, with a L. f. intermedius appearance, in the Barents Sea region. The dominating OCs in lesser black-backed gulls were polychlorinated biphenyls (PCB) and p,p'-dichlorodiphenyldichloroethylene (DDE). DDE and beta-hexachlorocyclohexane (beta-HCH) residues were higher in L. f. fuscus compared to L. f. intermedius and greyish-mantled birds in the Barents Sea region. In the latter area, blood residues of PCB and DDE in lesser black-backed gulls were as high as in great black-backed gulls, Larus marinus, while in the other regions they were lower. The higher DDE residues in endangered L. f. fuscus compared to increasing L. f. intermedius and greyish-mantled birds, which are invading northern Norway, suggest that OCs may have played a role in the population decline of L. f. fuscus, possibly in combination with nutrient stress.     

Petroleum Pollutant Degradation by Surface Water Microorganisms (8 pp)

Background, Aims and Scope It is well known that the composition of petroleum or some of its processing products changes in the environment mostly under the influence of microorganisms. A series of experiments was conducted in order to define the optimum conditions for an efficient biodegradation of petroleum pollutant, or bioremediation of different segments of the environment. The aim of these investigations was to show to what extent the hydrocarbons of a petroleum pollutant are degraded by microbial cultures which were isolated as dominant microorganisms from a surface water of a wastewater canal of an oil refinery and a nitrogen plant. Biodegradation experiments were conducted on one paraffinic, and one naphthenic type of petroleum during a three month period under aerobic conditions, varying the following parameters: Inorganic (Kp) or an organic medium (Bh) with or without exposition to light. Methods Microorganisms were analyzed in a surface water sample from a canal (Pančevo, Serbia), into which wastewater from an oil refinery and a nitrogen plant is released. The consortia of microorganisms were isolated from the water sample (most abundant species: Phormidium foveolarum - filamentous Cyanobacteria, blue-green algae and Achanthes minutissima, diatoms, algae). The simulation experiments of biodegradation were conducted with the biomass suspension and crude oils Sirakovo (Sir, paraffinic type) and Velebit (Ve, naphthenic type). After a three month period, organic substance was extracted by means of chloroform. In the extracts, the content of saturated hydrocarbons, aromatic hydrocarbons, alcohols and fatty acids was determined (the group composition). n-Alkanes and isoprenoid aliphatic alkanes, pristane and phytane, in the aliphatic fractions, were analyzed using gas chromatography (GC). Total isoprenoid aliphatic alkanes and polycyclic alkanes of sterane and triterpane types were analyzed by GC-MS. Results and discussion. Paraffinic type petroleums have a significant loss of saturated hydrocarbons. For naphthenic type petroleum, such a trend has not been observed. The most intensive degradation of n-alkanes and isoprenoid aliphatic alkanes (in paraffinic oil) and isoprenoids (in naphthenic oil) was observed using the inorganic medium Kp in the light; the microbial conversion is somewhat lower with Kp in the dark; with organic medium Bh in the light the degradation is of low intensity; with the same medium in the dark the degradation is hardly to be seen. Steranes and triterpanes were not affected by microbial degradation under the conditions used in our experiments. Obviously, the petroleum biodegradation was restricted to the acyclic aliphatics (n-alkanes and isoprenoids). Conclusion Phormidium foveolarum (filamentous Cyanobacteria - blue-green algae) and Achanthes minutissima (diatoms, algae), microbial cultures isolated as dominant algae from a surface water in a wastewater canal of an oil refinery and a nitrogen plant, have degradable effects dominantly involving petroleum hydocarbons. Petroleum microbiological degradation is more intensive when inorganic medium (in the light) is applied. Having in mind that the inorganic pollutants have been released into the canal as well, this medium reflects more the natural environmental conditions. Polycyclic alkanes of sterane and triterpane type, in spite of the fact that these compounds could be degraded, have remained unchanged regarding abundance and distribution. Since this is the case even for naphthenic type petroleum (which is depleted in n-alkanes), it can be concluded that the biodegradation of petroleum type pollutants, under natural conditions, will be restrained to the n-alkane and isoprenoid degradation. Recommendation and Outlook Performed experiments and simulations of petroleum microbiological degradation may serve for the prediction of the fate of petroleum type pollutants, as well as for definition of conditions for bioremediation of some environmental segments.     

Model estimation and measurement of ammonia emission from naturally ventilated dairy cattle buildings with slatted floor designs

Laboratory experiments were carried out in a wind tunnel with a model of a slurry pit to investigate the characteristics of ammonia emission from dairy cattle buildings with slatted floor designs. Ammonia emission at different temperatures and air velocities over the floor surface above the slurry pit was measured with uniform feces spreading and urine sprinkling on the surface daily. The data were used to improve a model for estimation of ammonia emission from dairy cattle buildings. Estimates from the updated emission model were compared with measured data from five naturally ventilated dairy cattle buildings. The overall measured ammonia emission rates were in the range of 11-88 g per cow per day at air temperatures of 2.3-22.4 degrees C. Ammonia emission rates estimated by the model were in the range of 19-107 g per cow per day for the surveyed buildings. The average ammonia emission estimated by the model was 11% higher than the mean measured value. The results show that predicted emission patterns generally agree with the measured one, but the prediction has less variation. The model performance may be improved if the influence of animal activity and management strategy on ammonia emission could be estimated and more reliable data of air velocities of the buildings could be obtained.     

The amniotic fluid as a source of mesenchymal stem cells with lung-specific characteristics

The amniotic fluid is a clinically accessible source of mesenchymal stem cells (AF-MSC) during gestation, which enables autologous cellular therapy for perinatal disorders. The origin of AF-MSC remains elusive: renal and neuronal progenitors have been isolated from the AF-MSC pool, yet no cells with pulmonary characteristics. We analyzed gene expression of pulmonary and renal markers of 212 clonal lines of AF-MSC isolated from amniocentesis samples. AF-MSC were cultured on dishes coated with extracellular matrix (ECM) proteins from decellularized fetal rabbit lungs. In vivo differentiation potential of AF-MSC that expressed markers suggestive of lung fate was tested by renal subcapsular injections in immunodeficient mice. Of all the isolated AF-MSC lines, 26% were positive for lung endodermal markers FOXA2 and NKX2.1 and lacked expression of renal markers (KSP). This AF-MSC subpopulation expressed other lung-specific factors, including IRX1, P63, FOXP2, LGR6, SFTC, and PDPN. Pulmonary marker expression decreased over passages when AF-MSC were cultured under conventional conditions, yet remained more stable when culturing the cells on lung ECM-coated dishes. Renal subcapsular injection of AF-MSC expressing lung-specific markers resulted in engrafted cells that were SPTB positive. These data suggest that FOXA2+/NKX2.1+/KSP- AF-MSC lines have lung characteristics which are supported by culture on lung ECM-coated dishes.