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PubMedDate not supplied

[The structure of the micromycete complexes of oligotrophic peat deposits in the southern taiga subzone of West Siberia].

The analysis of the micromycete complexes of oligotrophic peat deposits in the Vasyugan Marsh by direct count and culture methods showed that the micromycete carbon comprises no more than 3% of the total peat carbon and that the microscopic fungal biomass varies from 2 to 13 tons/hectare, depending on the season and the peat deposit thickness. Fungal spores were found in all layers of the peat deposits, whereas the mycelium was found only in the active peat layer. The high abundance of eukaryotic cells in the peats was due to the presence of yeastlike cells rather than fungal spores. Analyses by culture methods showed that micromycetes were present in all peat layers and that their abundance tended to decrease with depth, except for yeasts, which were uniformly distributed in a vertical direction. The micromycete complexes of the peat deposits were similar in the diversity and abundance of dominant species but differed in the composition of minor species. Peat yeasts were dominated by ascomycetes.

Ascomycota↗
PubMed2002

Impact of a commercial peat moss operation on water quality and biota in a small tributary of the Richibucto River, Kent County, New Brunswick, Canada.

The St-Charles Plain (Kent County, New Brunswick, Canada) commercial peat moss operation has been ongoing since 1983. To process the peat, a dry extraction method is used that requires extensive drainage of the peat bog. The water is directed toward sedimentation ponds, where it drains into a small brook, which feeds into a river affected by tidal salt water. Water discharge from the bog contains large amounts of peat particles that deposit in the surrounding watershed. As a result, the pH of the freshwater sites that receive the drainage water from the commercial operation, is fairly acidic (pH 3.9-4.7). Water samples from or near the peat moss operation have a higher concentration of total phosphorous and total organic carbon. The peat particles contain relatively high levels of total mercury, as reflected by analysis of peat sediments. However, the water samples contained low levels of dissolved mercury. Indigenous samples of biota-namely, sand shrimps (Crangon septemspinosa) and mummichogs (Fundulus heteroclitus)-did not contain mercury levels higher in the impacted sites than in the reference sites. Introduced blue mussels (Mytilus edulis) did not accumulate significant amounts of mercury during a 62-day exposure in the study area. Overall, the data suggest that although relatively large amounts of mercury-containing peat particles are discharged into the ecosystem, bioaccumulation of mercury in the biota does not occur.

Animals↗
PubMed2006

Effect of clay content and wetting-and-drying on radiocaesium behaviour in a peat and a peaty podzol.

The interaction of radiocaesium with peat under two moisture regimes was studied in laboratory experiments and by growing ryegrass in pot experiments to simulate changing field moisture conditions. A peat untreated and treated with 5% by weight of clay containing 46% illitic minerals, and a peaty podzol naturally containing 4.5% mineral matter on a dry weight basis were contaminated with (134)Cs and incubated. The soils were exposed to 8 wetting-and-drying cycles or kept constantly wet during 40 days. Extraction of the peat with 1 M CH(3)COONH(4) (pH 7) repeated after each wetting-and-drying cycle indicated increasing (134)Cs fixation with time of incubation. The peat treated with clay showed a much higher (134)Cs fixation than that without clay. The pot experiment with the incubated soils showed a (134)Cs transfer to ryegrass of the same order for the peaty podzol as for the peat treated with clay. For the peat untreated with clay the (134)Cs transfer to ryegrass was much greater. Wetting-and-drying the peat, with or without clay, increased the overall yield of grass and the concentration and uptake of (134)Cs over 5 consecutive harvests. K-fertilisation increased the yield of plant material (except for the peat with added clay), decreased the concentration of (134)Cs, but had no significant effect (p=0.05) on the resultant uptake of (134)Cs. Mixing clay with the surface layer of organic soils appears to be an effective means of decreasing radiocaesium transfer to field crops in fallout situations.

Aluminum Silicates↗
PubMed2001

Influence of peat on Fenton oxidation.

A diagnostic probe was used to estimate the activity of Fenton-derived hydroxyl radicals (.OH), reaction kinetics, and oxidation efficiency in batch suspensions comprised of silica sand, crushed goethite (alpha-FeOOH) ore, peat, and H2O2 (0.13 mM). A simple method of kinetic analysis is presented and used to estimate the rate of .OH production (POH) and scavenging term (ks), which were used to establish the influence of organic matter (Pahokee peat) in Fenton systems. POH was greater in the peat-amended systems than in the unamended control, and ks was approximately the same. Any increase in scavenging of .OH that resulted from the addition of peat was insignificant in comparison to radical scavenging by reaction with H2O2. Also, treatment efficiency, defined as the ratio of probe conversion to H2O2 consumption over the same period was greater in the peat-amended system. Results suggest that .OH production is enhanced in the presence of peat by one or more peat-dependent mechanisms. Fe concentration and availability in the peat, reduction of Fe(III) to Fe(II) by the organic matter, and reduction of organic-complexed Fe(III) to Fe(II) are discussed in the context of the Fenton mechanism.

Hydroxyl Radical↗
PubMed1999

Sorption of pentachlorophenol on peat-bentonite mixtures.

Batch kinetic and isotherm studies were carried out to determine the adsorptive characteristics of peat and bentonite mixtures for pentachlorophenol, and to examine the hydraulic conductivity of peat-bentonite mixtures to determine if they are applicable for use as cutoff barriers. Batch kinetic studies showed that over 90% of PCP was removed from water spiked with approximately 1 mg/l of PCP using a peat-bentonite (5%) mixture. The equilibrium time was 8 hours. The optimum pH range for adsorption of PCP by the peat-bentonite mixture was found to be 3-3.5. Batch isotherm studies showed that the adsorption of PCP by the peat-bentonite mixture from aqueous solution was best described by the Freundlich isotherm equation. Batch adsorption studies using various ratios of bentonite in the mixture showed that the adsorption of PCP decreased linearly with increased amount of bentonite in the mixture, indicating that adsorption of PCP by the peat moss portion of the mixture was the dominant process. The inverse of the hydraulic conductivity was found to increase exponentially with an increase in the bentonite content of the mixture over the range studied. The minimum hydraulic conductivity observed was 3.3 x 10(-7) cm/s for a 50% peat-50% bentonite mixture. Peat-bentonite mixtures can be used to successfully remove PCP from aqueous media and can be used effectively as a barrier to attenuate the migration of PCP through soil and groundwater systems.

Adsorption↗
PubMed2002

Enrichment of Cu, Ni, Zn, Pb and As in an ombrotrophic peat bog near a Cu-Ni smelter in southwest Finland.

The accumulation of selected trace elements (Cu, Ni, Zn, Pb, As) in the surface peat layer of an ombrotrophic bog 2.4 km from a Cu-Ni smelter at Harjavalta, Finland was studied using a peat core. A reference core was taken from an ombrotrophic bog at a background site, Hietajärvi, in eastern Finland. Element concentrations were analysed from 1-cm slices and enrichment factors (EF) were calculated. The enrichment factors of both Cu and Ni in the Harjavalta peat bog are extremely high compared to the Hietajärvi site. However, only the 6-cm surface peat Pb values are higher in Harjavalta compared to Hietajärvi. Precipitation was collected during 1992-1996, in the vicinity of the Harjavalta smelter, in order to estimate the current atmospheric deposition load. Comparison between the precipitation and peat data reveals that at Harjavalta the surface peat is relatively much more polluted than the current precipitation. The variation in EF of the Harjavalta peat core with respect to depth shows two patterns: Cu and Pb are similar, as are Ni, Zn and As. The vertical gradient in Harjavalta Cu EF suggests that Cu supplied to the peat by atmospheric deposition is very well preserved by the bog.

Environmental Monitoring↗
PubMed2002

In situ fluidization for peat bed rupture, and preliminary economic analysis.

This study concerns in situ fluidization (ISF), a new remediation method with potential application to the remediation of NAPL and heavy metal contaminants, by their release from the fluidized zone generated by a water jet. The present study examines the effect of ISF on layers of peat, of significance owing to its role as an important NAPL and metal contaminant trap. Once trapped, such contaminants are not readily accessible by most remedial methods, due to the low permeability and diffusivity of the peat. A simple tank experiment is used to demonstrate rupture of a peat layer by ISF, with removal of the peat as elutriated fines and segregated peat chunks. The application of ISF in the field is then examined by three field trials in uncontaminated sands, in both saturated and unsaturated conditions. Fluidized depths of up to 1.9 m in the saturated zone (with refusal on a peat layer) and 2.5 m in the unsaturated zone (no refusal) were attained, using a 1.9-m-long, 50 mm diameter jet operated at 5-13 1 s(-1). Pulses of dark turbidity and shell fragments in the effluent indicated the rupture of peat and shelly layers. The experiments demonstrate the hydraulic viability of ISF in the field, and its ability to remove peat-based contaminants. The issues of appropriate jet design and water generation during ISF are discussed, followed by a preliminary economic analysis of ISF relative to existing remediation methods.

Costs and Cost Analysis↗
PubMed2001

Storage and distribution of trace metals and spheroidal carbonaceous particles (SCPs) from atmospheric deposition in the catchment peats of Lochnagar, Scotland.

Lochnagar is a remote mountain lake to the south-east of the Cairngorm region in Scotland. Its catchment receives anthropogenic trace metals solely from atmospheric deposition. Ten peat cores were taken from the catchment and analysis confirmed that they have been contaminated by trace metals. The peats have an high affinity for trace metals and this results in metal accumulation in the surface peat layers. The formation of trace metal sulphides may also reduce remobilisation. In this way, trace metals derived from atmospheric deposition have been scavenged and accumulated. In contaminated peat layers, 77.4% Hg, 89.6% Pb, 93.4% Cu, 72.4% Zn and 86.5% Cd of the total stored are from anthropogenic sources. The accumulated trace metals in the peats can potentially influence the lake system through erosion. Spheroidal carbonaceous particle (SCP) profiles were used to date the peat cores. By referring to the SCP profiles in the peats and comparing these with the trace metal profiles in the lake sediments, the mobility of trace metals in the catchment peats is confirmed.

Air Pollutants↗
PubMed2004

Halogen retention, organohalogens, and the role of organic matter decomposition on halogen enrichment in two Chilean peat bogs.

Natural formation of organohalogen compounds can be shown to occur in all natural environments. Peat bogs, which are built up exclusively of organic matter and cover approximately 3% of the total continental world area, are potentially significant reservoirs for organohalogen formation. Up to now, fluxes and retention rates of halogens and organohalogen formation in peat bogs were mostly unquantified. In our study, we investigated the retention of atmospheric derived halogens and the natural formation of organohalogens by differential halogen analysis in two peat bogs in southernmost Chile. Atmospheric wet deposition rates of chlorine, bromine, and iodine range between 600 and 36000, 6 and 160, and 1 and 3 mg m(-2) yr(-1), respectively. Mean annual net accumulation rates of these halogens in peat are calculated to be 12-72 mg of Cl m(-2), 1.7-12 mg of Br m(-2), and 0.4-1.2 mg of l m(-2). Retention rates are similarly high for iodine (36-46%) and bromine (7.5-50%), and substantially lower for chlorine (0.2-2%). To evaluate influences of peat decomposition processes on halogen enrichment, halogen concentrations were compared to carbon/nitrogen ratios (C/N). Our results indicate that up to 95% of chlorine, 91% of bromine, and 81% of iodine in peat exist in an organically bound form. The results also indicate that the concentrations of halogens, especially of bromine and iodine, in peat are largely determined by peat decomposition processes and that halogens are not conservative in bogs.

Biodegradation, Environmental↗
PubMedDate not supplied

The adsorption of lead and copper from aqueous solution on modified peat-resin particles.

Raw peat was modified with sulfuric acid, then mixed modified with resin to prepare the modified peat-resin particles. Using the batch experimental systems, the removal of heavy metals (copper and lead) on the modified peat-resin particles was investigated. The data of the adsorption isotherm could be fitted by the Langmuir equation well. The adsorption rate of heavy metals on modified peat-resin particles was very swift. The removal processes of heavy metals on modified peat-resin particles could be well described by pseudo-second order model. The adsorption rate of lead was affected by the initial heavy metal concentration, initial pH, particle size, agitation speed and particle mass. In the adsorption of heavy metals (lead and copper) on the modified peat-resin particles, ion exchange was the major reaction mechanism. Desorption data showed that the lead adsorbed by modified peat-resin particle could be desorbed by 0.5 N or 1.0 N HNO3. The desorption rate was swift. The experiments indicated that the modified peat-resin particles have great potential for the removal of heavy metals from wastewater.

Adsorption↗
PubMed2002

Morphological changes of rhizobia in peat cultures.

Morphological changes that take place in peat cultures of several species of rhizobia were examined. These changes seemed to be associated with enhanced survival of cells in peat and after inoculation onto plastic beads, which were used as a model system for seeds. Cell wall changes, in which the periplasmic space appeared to be occluded with electron-dense material, were observed in Rhizobium sp. strain SU343 and Bradyrhizobium lupini WU425 cells after 7 and 14 days in peat, respectively. Nutrient limitation and low O(2) concentration in peat are suggested to be factors involved in the induction of the morphological changes. Polyhydroxybutyrate reserves, which were present in broth-cultured cells of both species of rhizobia, were mobilized after transfer into peat but did not appear to influence survival after inoculation onto beads. Enhanced expression of an iron-manganese superoxide dismutase was also observed after the cells were transferred into peat. We conclude that cell wall thickening in rhizobia after transfer from broth cultures into peat is an adaptive response for long-term survival under nutrient-limited conditions in peat. Cells with thickened walls may also be more resistant to other types of stress, such as that encountered on a seed surface.

Colony Count, Microbial↗
PubMed2003

Use of phospholipid fatty acids to detect previous self-heating events in stored peat.

The use of the phospholipid fatty acid (PLFA) composition of microorganisms to detect previous self-heating events was studied in naturally self-heated peat and in peat incubated under temperature-controlled conditions. An increased content of total PLFAs was found in self-heated peat compared to that in unheated peat. Two PLFAs, denoted T1 and T2, were detected only in the self-heated peat. Incubation of peat samples at 25 to 55 degrees C for 4 days indicated that T1 and T2 were produced from microorganisms with different optimum temperatures. This was confirmed by isolation of bacteria at 55 degrees C, which produced T2 but not T1. These bacteria produced another PLFA (denoted T3) which coeluted with 18:1omega7. T2 and T3 were identified as omega-cyclohexyltridecanoic acid and omega-cyclohexylundecanoic acid, respectively, indicating that the bacteria belonged to the genus Alicyclobacillus: T1 was tentatively identified as omega-cycloheptylundecanoic acid. T2 was detected 8 h after the peat incubation temperature was increased to 55 degrees C, and maximum levels were found within 5 days of incubation. The PLFA 18:1omega7-T3 increased in proportion to T2. T1 was detected after 96 h at 55 degrees C, and its level increased throughout the incubation period, so that it eventually became one of the dominant PLFAs after 80 days. In peat samples incubated at 55 degrees C and then at 25 degrees C, T1 and T2 disappeared slowly. After 3 months, detectable levels were still found. Incubation at 25 degrees C after heating for 3 days at 55 degrees C decreased the amounts of T2 and 18:1omega7-T3 faster than did incubation at 5 degrees C. Thus, not only the duration and temperature during the heating event but also the storage temperature following heating are important for the detection of PLFAs indicating previous self-heating.

Bacteria↗
PubMed2000

[Mechanism of the effect of aqueous peat extract on spontaneous contractile activity of smooth muscles].

BACKGROUND: There are reports in the literature about the effects of peat and its products on spontaneous contractile activity (SCA) of smooth muscles. In our earlier work we showed that the aqueous peat extract is a stimulus for SCA of smooth muscle fibres. After longstanding (4-5 h) influence from aqueous peat extract, a self-blocking effect of these influences can be observed. The mechanism of action could not be determined up to now. PURPOSE: The purpose of this study is to elucidate the peat mechanism of action. MATERIAL AND METHODS: In organ baths, the effects of aqueous peat extract on the SCA from smooth muscles have been studied under normal conditions and with presence of different receptor blocking substances. RESULTS: Our investigations show that only with simultaneous blocking of alpha(2) and D(2) receptors the stimulating activity of aqueous peat extract on the SCA of smooth muscle fibres can be suppressed. The self-blocking actions of the stimulating activity of aqueous peat extract on the SCA of smooth muscles are interconnected with blocking of alpha(2 ) adreno and D(2) receptors. CONCLUSION: The aqueous peat extract contains biologically active substances, which have a partial agonistic effect on alpha(2 ) and D(2) dopamine receptors. Corresponding to the results we start out at pharmacological effects as they are known from the mentioned receptors. The clinical efficacy have to be shown by clinical trials.

Animals↗
PubMedDate not supplied

[The saprotrophic bacterial complex in the raised peat bogs of Western Siberia].

The population density of bacteria in peat deposits along the landscape profile of the Vasyugan Marsh has been found to be as high as tens of millions of CFU/g peat. The abundance and diversity of bacteria increased with depth within the peat deposit, correlating with an increasing level of peat degradation. Variations in these parameters with depth and season were greater in peat deposits located in transaccumulative and transitional positions than in the sedge-sphagnum bogs located at the eluvial region of the profile. In the upper 1-m-thick layer of the peat deposits studied, bacilli, represented by five species, dominated, whereas, in the deeper layers, spirilla and myxobacteria prevailed. These bacteria were major degraders of plant polymers. Unlike the bacterial communities found in the peat deposits of European Russia, the dominant taxa in the studied peat deposits of Western Siberia are represented by bacteria resistant to extreme conditions.

Bacteria↗
PubMed1991

[Successful prevention of adhesions using peat and humic acids].

In order to verify the adhesion preventing capability of peat and peat components, 180 female rats were subjected to therapeutic bathing after standardised lesions had been placed on both uterine horns and the peritoneum of the anterior abdominal wall. From the 3rd and 7th day after surgery, respectively, randomized groups of animals consisting of 20 animals each were bathed in tap water, pure fresh peat, peat solution after pressing, centrifugation and filtration, and a solution of humic acids extracted from peat, all at the same temperature. One week after bathing for three weeks, the rats were relaparotomized, and quality and degree of the adhesions found were documented. Significant less and minor (p less than 0.001) adhesions were found in animals bathed in humic acid solution compared to the animals which had not been bathed at all. Peat solution and fresh peat reduced the formation of adhesions significantly, too, while warm water baths did not show any antiadhesive effect. Our results suggest humic acids to be the most effective component of peat with regard to the prevention of adhesions.

Animals↗
PubMed2001

Metal distribution and binding in balneological peats and their aqueous extracts.

Binding of metals in typical bath peat samples ("Grosses Gifhomer Moor", Sassenburg/North Germany) and their aqueous extracts was characterized by means of a multi-method approach. For that purpose a sequential extraction procedure based on peat-filled chromatography columns was developed. Water-soluble metal and DOM (dissolved organic matter) fractions were subdivided by use of a stepwise increased pH gradient (pH 3.8-5), finally by the chelator EDTA and 0.1 mol L(-1) hydrochloric acid. Metal fractions very strongly bound to peat were assessed by an aqua regia extraction. Metal determinations required were performed by atomic spectrometry methods (AAS, ICP-OES, and TXRF). The metal and DOM concentrations in the peat extracts varied significantly, depending on the natural variety of the peat matter under study (e.g., Al: 25-674, Cd: 0.05-0.2, Cu: 5-15.4, Fe: 77-1785, Mn: 21-505, Ni: 2-33, Pb: < 1, Zn: 9-715 (microg L(-1)); Na: 8-45, K: 1.3-14.9, Ca: 2-51, Mg: 1.1-7.9 (mg L(-1)); 26-73 mg L(-1) DOC). An increase of the pH increased the DOC (dissolved organic carbon) of the peat extracts, but hardly the concentration of heavy metals. The latter could only be re-mobilized by EDTA and dilute hydrochloric acid. Additional investigations of the peat extracts using tangential-flow ultrafiltration revealed that the heavy metals extracted at pH < 4 were predominantly dissociated. At higher pH (pH > 4.5) they were preferentially bound to macromolecular DOM. Moreover, using multistage ultrafiltration the size distribution of the DOM and their metal species was assessed.

Algorithms↗
PubMed2005

Practical and mechanistic aspects of the removal of cadmium from aqueous systems using peat.

A sphagnum peat moss removed Cd from aqueous solutions very efficiently, and its effectiveness in taking up the metal was significantly enhanced by exposure to a 1N NaOH solution. The capacity of the untreated peat for Cd reached 300 g/kg and that of the NaOH-activated peat was over 400 g/kg. Although saturation was rarely reached, the Cd uptake from concentrated solutions often exceeded 200 g/kg. In column experiments, 1g of the NaOH-activated peat completely removed the metal from over 0.2L of a 200-mg/L Cd solution (final Cd concentration<0.1mg/L), while 1g of non-activated peat cleared Cd from less than 25% of that volume. The cation exchange capacity measured for the peat depended on the time of contact with the exchanging solution. After 72 h contact, the value for the NaOH-activated peat was 135 cmol(c)/kg. In addition to uptake by exchange, a significant amount of Cd was sorbed by non-exchange mechanisms. FTIR spectroscopy revealed the importance of carboxyl groups in the uptake.

Cadmium↗
PubMed2004

A simple method for differential isolation of freely dispersed and particle-associated peat microorganisms.

Differential isolation of physiologically and ecologically diverse microbial groups facilitates evaluation of their activities in the environment. Here we describe a new method for differential isolation of freely dispersed and particle-associated peat microorganisms. The method is based on sequential elution of peat. Two types of natural peat, "young" sphagnum peat and "old" reed-based peat that have significantly different molecular composition as revealed by solid-state 13C NMR, were used for the method development. Various combinations of elution parameters (pH values, surfactant concentration, and sonication) were tested. Protein yield, CFU counts, 16S rDNA gene sequence, and T-RFLP analyses were used as criteria for evaluating the effectiveness of the elution protocols. The optimal method consisted of sequential elutions with (i) pH 6.2, 0.1 M potassium phosphate buffer, (ii) the same buffer amended with 0.01% of Tween 80, and (iii) treatment (ii) amended with sonication for 2 min. This method allowed differential isolation of freely dispersed and particle-associated microorganisms with (i) highest yield, (ii) highest diversity within the each microbial fraction, and (iii) best discrimination between the freely dispersed and particle-associated microbial communities. The method was applied for characterization of peat microbial communities and revealed different taxonomic composition and similar spatial organization of sphagnum and reed-sage peat microorganisms.

Arthrobacter↗