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Suitability of altai wildrye (Elymus angustus) and slender wheatgrass (Agropyron trachycaulum) for initial reclamation of saline composite tailings of oil sands.

The reclamation of freshly produced composite or consolidated tailings (CT) is a challenge for the Oil Sands Industry in the boreal forest of Western Canada. CT tailings materials are characterized by a relatively high salinity (dominated by sodium, sulphate and chloride) and a high pH (8-9). A greenhouse study was conducted to determine the germination, survival, injury and early plant growth of two grass species recommended for land reclamation, altai wildrye (Elymus angustus Trin) and slender wheatgrass (Agropyron trachycaulum Link Malte), growing in two different oil sand CT tailings (alum-CT and gypsum-CT), with and without peat amendment. Ion accumulation in the resulting plant tissues was determined. Our results showed that slender wheatgrass was most affected by the tailings at the germination stage, while for altai wildrye, the early growth stage was the most sensitive stage. Alum-CT had similar or less negative impact on plants than gypsum-CT. Amendment of CT with peat limited the reduction in germination and growth that was recorded in plants growing directly in CT. Based on these results, recommendations were made to improve reclamation strategies.

Agropyron↗

Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK.

Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably.

Air Pollutants↗

The Pb pollution fingerprint at Lochnagar: the historical record and current status of Pb isotopes.

Ratios of 206Pb/207Pb in a Lochnagar sediment core slowly decline from c. 1.32 at 140 cm to c. 1.23 at 9 cm, and then rapidly decline to c. 1.15 at the surface. Ninety percent of the Pb in the surface sediments can be attributed to anthropogenic sources. The 206Pb/207Pb ratio data imply that catchment peat surface contains a higher fraction of anthropogenic Pb than the sediment surface. The 206Pb/207Pb ratios in the surface of the sediment core are consistent with ratios in trapped sediments collected annually between 1998 and 2003. However, there is no significant decline in these recent samples suggesting that the reduction in atmospheric Pb emissions has not yet been recorded by the sediments due to Pb inputs from the catchment. As catchment peats store about 840 kg previously deposited anthropogenic Pb since 1860, it is likely that catchment inputs will continue to affect future 206Pb/207Pb ratios.

Air Pollutants↗

Similarity of bacterial communities in sawdust- and straw-amended cow manure composts.

We analyzed bacterial communities in two cow manure composts derived from the same feed manure and composted in the same location, but composted with different carbon amendments, and in peat-based potting mixes amended with these composts. Bacterial communities were characterized by PCR-denaturing gradient gel electrophoresis (DGGE) analysis of extracted DNAs, and population fingerprints generated for each sample were compared. Sequence analyses of dominant DGGE bands revealed that members of the phylum Bacteroidetes were the most dominant bacteria detected in this study (19 of 31 clones). These analyses demonstrate that bacterial community profiles of individual composts were highly similar, as were profiles of compost-amended potting mixes. However, potting mix profiles differed substantially from the original compost profiles and from that of the peat base. These data indicate that highly similar bacterial populations were active in the two composts, and suggest that the effects of the initial carbon amendment on the mature compost bacterial communities were minor, while factors such as the feed manure and composting location may have been more influential.

Animals↗

Solid substrate production of Epicoccum nigrum conidia for biological control of brown rot on stone fruits.

Production of conidia of Epicoccum nigrum, a biocontrol agent of the fungal pathogen Monilinia laxa, was tested in liquid- and solid-state fermentation. Liquid fermentation was conducted in 250 ml Erlenmeyer flasks containing 50 ml of a mineral medium (containing per litre: 20 g lactose, 10 g NO3K, 1 g K2HPO4, 0.5 g MgSO4.7H2O, and 1 ml of a minor-element solution), inoculated with 2 x 10(5) E. nigrum conidia ml(-1), and incubated at 20-25 degrees C and 150 rpm for 7 days. Solid-state fermentation was carried out in specially designed plastic bags (600 cm3) (VALMIC) containing either 50 g of peat/vermiculite (1:1, w/w), or 50 g of peat/vermiculite/lentil meal (1:1:1, w/w/w) with 40% (v/w) initial moisture content. Substrate was inoculated with a conidial suspension of E. nigrum to give 10(5) conidia g(-1) substrate, and bags were incubated at 20-25 degrees C for 7 days in darkness. The amount of conidia of E. nigrum obtained in solid-state fermentation with substrate based on peat/vermiculite/lentil meal was 10-fold higher than with substrate based on peat/vermiculite or in liquid fermentation. Conidial production under these conditions was maintained in the range of 10(8) conidia g(-1) substrate from 10 to 150 days after inoculation. Germinability of these conidia was >90%. Addition of other nutrients than lentil meal to peat/vermiculite did not enhance production of conidia. Presence of peat in the substrate was necessary for good conidia production, but change in the kind of peat or vermiculite did not improve conidial production. Conidial production was similar when the substrate was inoculated with 10(5), 10(6) or 10(7) conidia g(-1) dry substrate. Incubation of bags in light conditions did not enhance conidial production. Fresh conidia produced in this solid-state fermentation system reduced the incidence and lesion diameter induced by M. laxa on peaches.

Ascomycota↗

Soil carbon stocks and changes in the Republic of Ireland.

The soil carbon (C) stock of the Republic of Ireland is estimated to have been 2048 Mt in 1990 and 2021 Mt in 2000. Peat holds around 53% of the soil C stock, but on 17% of the land area. The C density of soils (tCha(-1)) is mapped at 2 km x 2 km resolution. The greatest soil C densities occur where deep raised bogs are the dominant soil; in these grid squares C density can reach 3000 tCha(-1). Most of the loss of soil C between 1990 and 2000-up to 23 MtC (1% of 1990 soil C stock)-was through industrial peat extraction. The average annual change in soil C stocks from 1990 to 2000 due to land use change was estimated at around 0.02% of the 1990 stock. Considering uncertainties in the data used to calculate soil C stocks and changes, the small average annual 'loss' could be regarded as 'no change'.

Carbon↗

Degradation of polycyclic aromatic hydrocarbons by combined chemical pre-oxidation and bioremediation in creosote contaminated soil.

The ability of pre-oxidation to overcome polycyclic aromatic hydrocarbons (PAH) recalcitrance to biodegradation was investigated in creosote contaminated soil. Sand and peat artificially spiked with creosote (quality WEI C) were used as model systems. Ozonation and Fenton-like treatment were proved to be feasible technologies for PAH degradation in soil. The efficiency of ozonation was strongly dependent on the water content of treated soil samples. The removal of PAH by Fenton-like treatment depended on the applied H2O2/soil weight ratio and ferrous ions addition. It was determined that the application of chemical oxidation in sand resulted in a higher PAH removal and required lower oxidant (ozone, hydrogen peroxide) doses. The enhancement of PAH biodegradability by different pre-treatment technologies also depended on the soil matrix. It was ascertained that combined chemical and biological treatment was more efficient in PAH elimination in creosote contaminated soil than either one alone. Thus, the combination of Fenton-like and the subsequent biological treatment resulted in the highest removal of PAH in creosote contaminated sand, and biodegradation with pre-ozonation was found to be the most effective technology for PAH elimination in peat.

Biodegradation, Environmental↗

Resolving Chernobyl vs. global fallout contributions in soils from Poland using Plutonium atom ratios measured by inductively coupled plasma mass spectrometry.

Plutonium in Polish forest soils and the Bór za Lasem peat bog is resolved between Chernobyl and global fallout contributions via inductively coupled plasma mass spectrometric measurements of 240Pu/230Pu and 241Pu/239Pu atom ratios in previously prepared NdF3 alpha spectrometric sources. Compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/230Pu and 241Pu/239Pu co-vary and range from 0.186 to 0.348 and 0.0029 to 0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407 x [240Pu/239Pu] - 0.0413; r2 = 0.9924). Two-component mixing models are developed to apportion 239+240Pu and 241Pu activities; various estimates of the percentage of Chernobyl-derived 239+240Pu activity in forest soils range from < 10% to > 90% for the sample set. The 240Pu/230Pu - 241Pu/239Pu atom ratio mixing line extrapolates to estimate 241Pu/239Pu and the 241Pu/239+240Pu activity ratio for the Chernobyl source term (0.123 +/- 0.0007; 83 +/- 5; 1 May 1986). Sample 241Pu activities, calculated using existing alpha spectrometric 239+240Pu activities, and the 240Pu/230Pu and 241Pu/239Pu atom ratios, agree relatively well with previous liquid scintillation spectrometry measurements. Chernobyl Pu is most evident in locations from northeastern Poland. The 241Pu activities and/or the 241Pu/239Pu atom ratios are more sensitive than 240Pu/239Pu or 238Pu/239+240Pu activity ratios at detecting small Chernobyl 239+240Pu inputs, found in southern Poland. The mass spectrometric data show that the 241Pu activity is 40-62% Chernobyl-derived in southern Poland, and 58-96% Chernobyl in northeastern Poland. The Bór za Lasem peat bog (49.42 degrees N, 19.75 degrees E), located in the Orawsko-Nowotarska valley of southern Poland, consists of global fallout Pu.

Environmental Monitoring↗

Effects of freezing and storage temperature on MS2 viability.

Monitoring human enteric virus levels in domestic wastewater effluent is crucial to protecting human health. Occasionally, during intensive sampling, wastewater samples must be stored for later viral analysis. Little data exist regarding how enteric viruses survive during storage at different temperatures in secondary treated wastewater. During a field-scale study assessing pathogen removal performance by various onsite treatment technologies, the MS2 bacteriophage, an indicator of enteric viruses, was inoculated into septic tank (STE), sand filter, peat filter and constructed wetland (CW) effluents to determine virus decay at various storage temperatures. Virus stored at temperatures > or =10 degrees C and at -20 degrees C decayed nearly twice as fast as those stored at 4 degrees C or -80 degrees C. Decreased water quality decreased viral decay rates at 4 degrees C and -80 degrees C, with slowest decay occurring in STE and the fastest in sterile PBS and low pH peat effluent. In CW effluent after 8 days, less MS2 was inactivated when stored at 4 degrees C (20%) compared to -80 degrees C (58%); however, during extended storage (approximately 300 days), less MS2 was inactivated at -80 degrees C (75%) compared to 4 degrees C (93%). We recommend that viruses in wastewater be stored in the dark at 4 degrees C unless storage for >40 days is necessary.

Bioreactors↗

Brief emotion training improves recognition of facial emotions in chronic schizophrenia. A pilot study.

Impaired emotional communication may be an important contributing factor to poor social function in schizophrenia. This pilot study examined the effect of emotion training exercises on the perception of facial emotional expression. Twenty male chronic schizophrenia patients underwent three training sessions using a computerized Emotion Training program, developed for teaching autistic children, which was adapted to the clinical setting. Patients were assessed before and after training with validated tests of identification of facial emotions (PEAT, ER40), differentiation of facial emotions (EmDiff) and working memory. In comparison to baseline, patients performed significantly better on the PEAT and ER40 tests after training. No change was observed in EmDiff or in cognitive test performance. Brief Emotion Training can improve recognition of facial emotional expressions in chronic schizophrenia patients. This may be due to increased patient awareness of emotional aspects of stimuli and/or improvement in specific emotional perceptual skills. Further studies of Emotion Training as a potential treatment modality are warranted.

Adult↗

Isotopic characterisation of the historical lead deposition record at Glensaugh, an organic-rich, upland catchment in rural N.E. Scotland.

As part of a wider investigation of the biogeochemistry and fate of Pb deposited from the atmosphere at Glensaugh, a rural upland catchment in N.E. Scotland, the concentration and isotopic composition of Pb were determined in four thinly sectioned monolith cores (25 cm) of peat collected at altitudes of 426--434 m from different faces of Thorter Hill and in a series of 21 10-cm unsectioned cores of peat and organic-rich soil along a transect from near the top (434 m) to the bottom (224 m) of the catchment. Depth profiles of Pb concentration and (206)Pb/(207)Pb ratio were similar for the longer cores. Subsurface Pb maxima (238--489 mg kg(-1)) typically occurred below (206)Pb/(207)Pb minima (1.123-1.134). One core was (210)Pb-dated and had a fairly constant (206)Pb/(207)Pb value of 1.170 from mid-19th century to ca. 1930, followed by a decline (attributable to the increasing influence of Australian Pb of much lower (206)Pb/(207)Pb ratio) to 1.134 by the early 1990s, and then a rapid increase to 1.160 by 2002, after the phased withdrawal of leaded petrol. The fluxes of Pb increased from 15 mg m(-2) year(-1) in the late 19th century to a peak of 60 mg m(-2) year(-1) ca. 1960, before declining steadily to 3.6 mg m(-2) year(-1) by the beginning of the 21st century. Some 40% of the anthropogenic Pb in the core had been deposited prior to 1900. The mean anthropogenic Pb inventory of the four longer cores was 7.4+/-1.5 g m(-2), of which approximately 70% occurred in the top 10 cm, in good agreement with the inventories of the shorter cores collected above 400 m. These inventories are higher than those of the industrial central belt of Scotland, probably because of enhanced deposition at altitude. This is consistent with the derived average (210)Pb flux of 198+/-11 Bq m(-2) year(-1), which is twice that of typical UK (210)Pb deposition and the rainfall for the site. The past deposition of Pb at Glensaugh, including that from sources (e.g., smelting, coal combustion) other than leaded petrol, has clearly been considerable. Even since the introduction of leaded petrol ca. 1930, car-exhaust emissions may have accounted for no more than 35% of the Pb deposited.

Journal Article↗

Mobilization of arsenic by dissolved organic matter from iron oxides, soils and sediments.

The arsenic contamination of aquifers has been linked to the input of dissolved organic matter (DOM). In light of this suggestion, the aim of this study was to quantify chemical effects of DOM on desorption and redox transformations of arsenic bound to synthetic iron oxide and natural samples from different geochemical environments (soils, shallow aquifer, lake sediment). In batch experiments, solutions containing 25-50 mg/L of two different types of DOM (purified peat humic acid and DOM from a peat drainage) were used as extractants in comparison to inorganic solutions. DOM solution was able to mobilize arsenic from all solid phases. Mobilization from iron oxides (maximum: 53.3%) was larger than from natural samples (maximum: 2.9%). The mobilization effect of extractants decreased in the order HCl>NaH2PO4>DOM>NaNO3. DOM solutions, therefore, mainly targeted weakly sorbed arsenic. Mobilization was complete within 24-36 h and DOM was sorbed during incubation indicating competition for sorption sites. The same patterns were observed for different DOM types and concentrations. Addition of DOM lead to (a) enhanced reduction (maximum 7.8%) and oxidation (6.4%) of arsenic in aqueous solution and (b) the appearance of arsenite in aqueous phase of soil samples (5.5%). As the primary mechanism for the arsenic release from solid phases we identified the competition between arsenic and organic anions for sorption sites, whereas redox reactions were probably of minor importance. The results of this study demonstrate that sorption of DOM has a strong potential to mobilize arsenic from soils and sediments.

Adsorption↗

The fate of experimentally deposited nitrogen in mesocosms from two Canadian peatlands.

In large regions of Europe and North America, peatlands have been exposed to elevated rates of atmospheric nitrogen (N) deposition. We investigated the fate of experimentally added N (NH(4)(15)NO3) at two different N loads (1.2 and 4.7 g N m(-2) yr(-1)) and water tables (1 and 32 cm) in intact cores from two peatlands, located in Central and Eastern Canada. The sites receive an estimated total N load of 0.6 g m(-2) a(-1) and 1.5 g m(-2) yr(-1), excluding nitrogen fixation. In all treatments, experimentally added nitrate (NO(3-)) was fully (96-99%) and ammonium (NH(4+)) mostly (81-97%) retained by the plant cover, mainly consisting of Sphagnum mosses, or in the unsaturated zone below. However, on average only 48% of the (15)N were recovered from the plant cover, and substantial amounts were found in depth layers of 2-6 cm (21-46%) and 8-12 cm (1.4-10.8%) below the moss surface. The amount of (15)N retained also significantly decreased with a lower water table from 56+/-9% to 40+/-10%. These findings document a substantial mobility of N, particularly during water table drawdown. Analysis of (15)N by a sequential diffusion procedure revealed a transfer of (15)N from NO(3-) into NH(4+) and dissolved organic N (DON), but the contents of (15)N in these pools accounted for less than 1% of the total N, natural background subtracted. The mass flux of dissolved (15)N into the peat was small compared to the total mass flux of (15)N. The accumulation of (15)N in the bulk peat must have been caused by a mechanism that was not investigated, possibly by transport of particulate organic N.

Air Pollutants↗

Impact of filter media on the performance of full-scale recirculating biofilters for treating multi-residential wastewater.

The main objective of this paper was to evaluate the effectiveness of silica sand, crushed glass, peat, and geotextile as a medium in RBFs in the removal for organic matter, nutrients and bacteria from domestic wastewater based on a field-scale study. In particular, this field-scale study was conducted to treat domestic wastewater from a small community of 10 households from the Municipality of Lunenburg, Nova Scotia, Canada. The average influent 5d biochemical oxygen demand (BOD(5)) and total suspended solids (TSS) concentrations into the field filter system were 381+/-64 (mean+/-standard deviation) and 46+/-21 mg/L, respectively. The results showed that crushed glass could be an effective medium in RBFs since the crushed glass filter produced stable effluent BOD(5) and TSS concentrations of less than 20mg/L. Geotextile was found to be another successful alternative filter medium with the effluent BOD(5) and TSS of 18+/-11 and 11+/-7 mg/L, respectively, even though the porosity of geotexitle filter was as high as 0.90. Peat was not able to provide efficient performance due to its poor BOD(5) and NH(4)(+)-N removals. This study measured the water quality variation at different components of the RBFs. The results of this study showed that the recirculation tank was the main facilitator of the denitrification process. In addition, this study found that RBFs could efficiently treat domestic wastewater for BOD(5) removal under the organic loading rates as high as 0.070 kg/m(2)/d.

Bioreactors↗

Charcoal suspension for tumor labelling modifies macrophage activity in mice.

We have previously developed a charcoal suspension for injection into human breast cancers in order to facilitate their location during surgery. We observed that charcoal particles were ingested by intra and peritumoral macrophages, some of which carried the particles at some distance from the injection site. We studied the influence of the formulation parameters of the charcoal suspension for intratumoral injection on in vitro and in vivo activation and in vivo mobilization of mouse peritoneal macrophages after intra-peritoneal injection of 2 mL of each preparation. The influence of the charcoal origin (peat vs wood), granulometry, suspension vehicle (water for parenteral injection, vs saline), concentration and excipients were studied. Micronized peat charcoal in water for injection at the highest studied concentration reduced macrophage activation in vitro and in vivo. However, macrophage mobilization was weaker than after thioglycolate injection and did not seem to be charcoal dose-dependent. The additives incorporated in the charcoal suspension led in vivo to increased peritoneal macrophage activation and mobilization (mannitol, and glucose), only increased activation (polysorbate 80 and pluronic F68) or mobilization (dextran 40, egg lecithin, and cabosil), or inhibited both activation and mobilization (cremophor EL).

Animals↗

Comparing Early to Middle Miocene floras and probable vegetation types of Oberdorf N Voitsberg (Austria), Bohemia (Czech Republic), and Wackersdorf (Germany).

The Early Miocene vegetation of western Styria, Austria, is reconstructed on the basis of detailed investigations of leaves and diaspores from the mining area Oberdorf N Voitsberg. In this paper, the flora and probable vegetation are compared with other assemblages of similar age from the Czech Republic and Germany to elucidate the diversity of wetland and mesophytic plant communities. The floristic composition and the vegetational units represented in Oberdorf are compared to the middle part of the Most Formation (M Most Fm), Cypris Shale, Mydlovary Formation (Mydlovary Fm) of Bohemia, and the Wackersdorf mining area of Bavaria. Among these sites, Oberdorf is extremely poor in hydrophytes and reed-like monocotyledons, indicating rare pond-like habitats as well as possibly more closed swamp forest conditions than, e.g. in the M Most Fm. In Oberdorf, relatively high pH-values in the lignite-forming swamps and the possible scarcity of acidic, nutrient-poor (sandy) soils have probably influenced the floristic composition of the azonal communities. The peat-forming associations in all regions share the abundance of Glyptostrobus europaeus. However, distinct differences in the accompanying elements, such as Taxodium dubium (present and abundant only in the M Most Fm) indicate even stronger floristic variability of Early(/Middle) Miocene peat-forming and riparian plant communities than previously expected. The virtual absence of Pinus, Engelhardia, Comptonia, and probably also of Quercus kubinyii/Quercus drymeja in the megafossil record of Oberdorf can possibly be explained by the edaphic conditions. The abundance of Sequoia abietina (absent in all the other compared sites), which we assign to riparian (and mesophytic) forests in Oberdorf, may have been favoured by rich alluvial soils.In the mesophytic associations, thermophilous elements of the Lauraceae, Mastixiaceae, Symplocaceae, and Rutaceae are diverse. Usually they include Trigonobalanopsis rhamnoides/Trigonobalanopsis exacantha, an evergreen Fagaceae. This assemblage type corresponds with the Younger Mastixioid Flora sensu Mai. The Younger Mastixioid Flora is best developed in Wackersdorf, less distinct in Oberdorf, and likely in the Cypris Shale and Mydlovary Fm. It is not traceable in the M Most Fm.

Journal Article↗

Pollen diagrams and prehistoric fields: the case of Bronze Age Haarlem, the Netherlands.

The excavation of a Bronze Age field surrounded by peat in the vicinity of the Dutch town of Haarlem afforded a good opportunity to study the pollen rain released by such prehistoric fields. Pollen analysis of a core obtained from a peat deposit at a distance of 10m from the field's border revealed only a weak signal of a possible field. The conclusion is that the presence of prehistoric fields is difficult to detect by means of pollen analysis alone.

Journal Article↗

Mobility of atrazine from alginate-bentonite controlled release formulations in layered soil.

The mobility of atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine] from alginate-bentonite-based controlled release (CR) formulations was investigated by using soil columns. Two CR formulations based on sodium alginate (14.0 g kg(-1), atrazine (6.0 g kg(-1), natural or acid-treated bentonite (50 g kg(-1), and water (924 g kg(-1) were compared to technical grade product and commercial liquid (CL) formulation (Gesaprim 500FW). All herbicide treatments were applied to duplicate layered bed systems simulating the typical arrangement under a plastic greenhouse, which is composed of sand (10 cm), peat (2 cm), amended soil (20 cm) and native soil (20 cm). The columns were leached with 39 cm (1500 ml) and 156 cm (6000 ml) of 0.02 M CaCl2 solution to evaluate the effect of water volume applied on herbicide movement. When 39 cm of 0.02 M CaCl2 solution was applied, there was no presence of herbicide in the leachate for the alginate-bentonite CR treatments. However, 0.11% and 0.14% of atrazine appeared in the leachate when the treatment was carried out with technical grade and CL formulations, respectively. When 156 cm of 0.02 M CaCl2 solution was applied, the use of the alginate-acid treated bentonite CR formulation retards and reduces the presence of atrazine in the leachate as compared to technical product. Analysis of the soil columns showed the highest atrazine concentration in the peat layer. Alginate-bentonite CR formulations might be an efficient system for reducing atrazine leaching in layered soil and thus, it could reduce the risks of pollution of groundwater.

Alginates↗