Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PEAT”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2006

The performance of fibrous peat biofilters in treating domestic strength wastewater.

Peat is an abundant resource in Ireland and has the capacity to be used in low-cost, low-maintenance wastewater treatment systems for single houses. In this study four fibrous peat columns, of varying depths were constructed and tested in the laboratory for their capacity to remove contaminants from domestic-strength synthetic wastewater. The four filters had peat depths of 0.3 m, 0.6 m, 0.9 m and 1.2 m. During the 360 day study the filters were intermittently loaded with domestic strength synthetic wastewater at a hydraulic loading rate of 180 l/m2cd. Hydrographs and residence times for each filter were examined as was their ability to remove impurities from the wastewater. Removal of 5-day biochemical oxygen demand (BOD5) and total chemical oxygen demand (CODt) were > or =96% and 84%, respectively, in all filters with almost complete nitrification (> or =99%) being recorded for each filter. The removal of total suspended solids (TSS) was excellent at > or =94% and no clogging was recorded on any filter during the study. For the 0.6 m, 0.9 m and 1.2 m deep filters, total viable counts (TVC) were less than EU surface water directive limits for Class A2 potable water sources. The systems were cheap to construct and very easy to maintain.

Adsorption↗
PubMed1983

Technetium and uranium: sorption by and plant uptake from peat and sand.

The objectives of this study were to compare the effects of technetium and uranium on the yield and uptake, and to identify the organ of accumulation, of an edible leafy vegetable growing in sandy and peaty soils. In sand, where the soil's sorption capacity is negligible, technetium uptake is four orders of magnitude higher than from peat, suggesting no plant mediation of uptake and thus a constant concentration factor (greater than 50) in an oxidizing environment where technetium is continuously supplied. The technetium is predominantly translocated to the shoots. When soil fixation occurs, as in peat, this becomes the controlling factor in the plant uptake of technetium. In the case of uranium, plant mediation is more significant. Uranium uptake by Swiss chard is up to 80 times higher from sand than from peat. The uranium is restricted to the root system and may only be precipitated on the outer root membrane and may not accumulate in the roots.

Plants, Edible↗
PubMed2005

Applied K fertilizer use efficiency in pineapples grown on a tropical peat soil under residues removal.

In Malaysia, pineapples are grown on peat soils, but most K fertilizer recommendations do not take into account K loss through leaching. The objective of this study was to determine applied K use efficiency under a conventionally recommended fertilization regime in pineapple cultivation with residues removal. Results showed that K recovery from applied K fertilizer in pineapple cultivation on tropical peat soil was low, estimated at 28%. At a depth of 0-10 cm, there was a sharp decrease of soil total K, exchangeable K, and soil solution K days after planting (DAP) for plots with K fertilizer. This decline continued until the end of the study. Soil total, exchangeable, and solution K at the end of the study were generally lower than prior values before the study. There was no significant accumulation of K at depths of 10-25 and 25-45 cm. However, K concentrations throughout the study period were generally lower or equal to their initial status in the soil indicating leaching of the applied K and partly explained the low K recovery. Potassium losses through leaching in pineapple cultivation on tropical peat soils need to be considered in fertilizer recommendations for efficient recovery of applied K.

Agriculture↗
PubMed2006

Characterization of acid-tolerant H/CO-utilizing methanogenic enrichment cultures from an acidic peat bog in New York State.

Two methanogenic cultures were enriched from acidic peat soil using a growth medium buffered to c. pH 5. One culture, 6A, was obtained from peat after incubation with H(2)/CO(2), whereas culture NTA was derived from a 10(-4) dilution of untreated peat into a modified medium. 16S rRNA gene clone libraries from each culture contained one methanogen and two bacterial sequences. The methanogen 16S rRNA gene sequences were 99% identical with each other and belonged to the novel "R-10/Fen cluster" family of the Methanomicrobiales, whereas their mcrA sequences were 96% identical. One bacterial 16S rRNA gene sequence from culture 6A belonged to the Bacteroidetes and showed 99% identity with sequences from methanogenic enrichments from German and Russian bogs. The other sequence belonged to the Firmicutes and was identical to a thick rod-shaped citrate-utilizing organism isolated from culture 6A, the numbers of which decreased when the Ti (III) chelator was switched from citrate to nitrilotriacetate. Bacterial clones from the NTA culture clustered in the Delta- and Betaproteobacteria. Both cultures contained thin rods, presumably the methanogens, as the predominant morphotype, and represent a significant advance in characterization of the novel acidiphilic R-10 family methanogens.

Acids↗
PubMed2000

Combined molecular ecological and confocal laser scanning microscopic analysis of peat bog methanogen populations.

Confocal laser scanning microscopy, using fluorescently labelled oligonucleotide probes targeting the 16S rRNA of different physiological groups of methanogens, was used to identify which methanogenic genera were present and to describe their in situ spatial locations in samples taken at different depths from blanket peat bog cores. Total bacterial DNA was also extracted and purified from the samples and used as template for amplification of 16S rRNA and regions of methyl CoM reductase-encoding genes using the polymerase chain reaction, as well as for oligonucleotide hybridisation experiments. These techniques, used in concert, demonstrated that methanogens of several physiological groups were present in highest numbers in the mid regions of 25 cm deep peat cores. Some discrepancies were apparent in the findings of the microscopic and molecular methods, though these may be partially accounted for by the different sensitivities of the techniques employed. The combined approaches used in this study gave an insight into the diversity and distribution of methanogens in peat environments not possible using molecular ecological methods alone.

DNA, Archaeal↗
PubMed1995

Identification of Rhizobium spp. in peat-based inoculants by DNA hybridization and PCR and its application in inoculant quality control.

Procedures based on DNA hybridization and PCR were developed for quality control of Rhizobium inoculants. Inoculants for pea and goat's rue were produced by Elomestari Ltd., Juva, Finland, in sterile dry fine peat by the standard procedure used by the company. The inoculants contained Rhizobium galegae HAMBI 1174 and HAMBI 1207 and an R. leguminosarum biovar vicia strain, 16HSA, either solely or in combinations of two or three strains. DNA was isolated from 1-g samples of each peat inoculant and analyzed by nonradioactive DNA-DNA hybridization and by PCR. The hybridization probes were total DNAs from pure cultures of R. galegae HAMBI 1207 and R. leguminosarum biovar viciae 16HSA and a 264-bp strain-specific fragment from the genome of R. galegae HAMBI 1174. The total DNA probes distinguished inoculants containing R. galegae or R. leguminosarum, and the strain-specific probe distinguished inoculants containing R. galegae HAMBI 1174. The hybridization results for R. galegae were verified in a PCR experiment by amplifying an R. galegae species-specific fragment and an R. galegae HAMBI 1174 strain-specific fragment in the same reaction. When suitable probes and primers are available, the methods described here offer promising alternatives for the quality control of peat-based inoculants.

Base Sequence↗
PubMed1998

Acidophilic methanotrophic communities from Sphagnum peat bogs.

Highly enriched methanotrophic communities (> 25 serial transfers) were obtained from acidic ombrotrophic peat bogs from four boreal forest sites. The enrichment strategy involved using media conditions that were associated with the highest rates of methane uptake by the original peat samples, namely, the use of diluted mineral medium of low buffering capacity, moderate incubation temperature (20 degrees C), and pH values of 3 to 6. Enriched communities contained a mixture of rod-shaped bacteria arranged in aggregates with a minor contribution of Hyphomicrobium-like cells. The growth stoichiometry of isolates was characteristic of methanotrophic bacteria (CH4/O2/CO2 = 1:1.1:0.59), with an average apparent yield of 0.41 +/- 0.03 g of biomass C/g of CH4-C. DNA from each enrichment yielded a PCR product of the expected size with primers for both mmoX and mmoY genes of soluble methane monooxygenase. Two types of sequences were obtained for PCR-amplified fragments of mmoX. One of them exhibited high identity to the mmoX protein of the Methylocystis-Methylosinus group, whereas the other showed an equal level of divergence from both the Methylosinus-Methylocystis group and Methylococcus capsulatus (Bath) and formed a distinct branch. The pH optimum for growth and for CH4 uptake was 4.5 to 5.5, which is very similar to that for the optimum CH4 uptake observed in the original peat samples. These methanotrophs are moderate acidophiles rather than acidotolerant organisms, since their growth rate and methane uptake were much lower at neutral pH. The growth of the methanotrophic community was enhanced by using media with a very low salt content (20 to 200 mg/liter), more typical of their natural environment. All four enriched communities grew on N-free medium.

Culture Media↗
PubMed2006

Phylogenetic analysis and in situ identification of bacteria community composition in an acidic Sphagnum peat bog.

The Bacteria community composition in an acidic Sphagnum peat bog (pH 3.9 to 4.5) was characterized by a combination of 16S rRNA gene clone library analysis, rRNA-targeted fluorescence in situ hybridization (FISH), and cultivation. Among 84 environmental 16S rRNA gene clones, a set of only 16 cloned sequences was closely related (>or=95% similarity) to taxonomically described organisms. Main groups of clones were affiliated with the Acidobacteria (24 clones), Alphaproteobacteria (20), Verrucomicrobia (13), Actinobacteria (8), Deltaproteobacteria (4), Chloroflexi (3), and Planctomycetes (3). The proportion of cells that hybridized with oligonucleotide probes specific for members of the domains Bacteria (EUB338-mix) and Archaea (ARCH915 and ARC344) accounted for only 12 to 22% of the total cell counts. Up to 24% of the EUB338-positive cells could be assigned by FISH to specific bacterial phyla. Alphaproteobacteria and Planctomycetes were the most numerous bacterial groups (up to 1.3x10(7) and 1.1x10(7) cells g-1 peat, respectively). In contrast to conventional plating techniques, a novel biofilm-mediated enrichment approach allowed us to isolate some representatives of predominant Bacteria groups, such as Acidobacteria and Planctomycetes. This novel strategy has great potential to enable the isolation of a significant proportion of the peat bog bacterial diversity.

Bacteria↗
PubMedDate not supplied

Dissolved organic carbon and disinfection by-product precursor release from managed peat soils.

A wetland restoration demonstration project examined the effects of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacramento-San Joaquin Delta of California. Conversion of agricultural land to a wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) release from the peat soils, relative to the previous land use. Dissolved organic C in delta waters is a concern because it reacts with chlorine, added as a disinfectant in municipal drinking waters, to form carcinogenic disinfection byproducts (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs). This study explores the effects of peat soil biogeochemistry on DOC and DBP release under agricultural and wetland management. Results indicate that organic matter source, extent of soil organic matter decomposition, and decomposition pathways all are factors in THM formation. The results show that historical management practices dominate the release of DOC and THM precursors. However, within-site differences indicate that recent management decisions can contribute to changes in DOC quality and THM precursor formation. Not all aromatic forms of carbon are highly reactive and certain environmental conditions produce the specific carbon structures that form THMs. Both HAA and THM precursors are elevated in the DOC released under wetland conditions. The findings of this study emphasize the need to further investigate the roles of organic matter sources, microbial decomposition pathways, and decomposition status of soil organic matter in the release of DOC and DBP precursors from delta soils under varying land-use practices.

Agriculture↗
PubMed2006

Peat fire effects on some properties of an artificially drained peatland.

The management of artificially drained organic soils is a very important issue, since the accelerated mineralization and sometimes peat fires alter physical and chemical properties of soils and the availability of plant nutrients. This study was performed to determine relatively short- and long-term effects of peat fires on some physical and chemical properties of soils in the artificially drained Gavur Lake Peatland of Turkey. To achieve this objective, measured properties of soils burned in 2001, burned in 1965, and unburned were compared. The results indicated that soil bulk density, pH, amounts of soluble salts, CaCO3, and concentrations of ammonium acetate-extractable (AAE) Ca, Mg, K, and Na were significantly higher for both sampling depths in the burned areas. The areas burned in 2001 had higher pH, soluble salts, and the concentrations of AAE Ca, Mg, and K compared with sites burned in 1965, and this was reasoned with leaching losses and plant uptake of these basic cations for four decades in the latter. Percent saturation and organic carbon contents of soils, however, were significantly lower in the burned areas for both sampling depths. Olsen P levels were not significantly different between the sites. This work clearly shows that alterations in soils properties with peat fires do not recover in the long term.

Fresh Water↗
PubMed2001

Odor control of an anaerobic lagoon with a biological cover: floating peat beds.

The use of a biological cover for in situ control of gaseous sulfide emission from an anaerobic pond was investigated by a laboratory-scale experiment. The biological cover, constituting by a peat bed floating on the wastewater, caused a reduction of the H2S emission rate by 84.6%. The addition of Fe3+ (with FeCl3) and plants (Juncus effusus L.) to the peat bed significantly improved the performance to reach a H2S removal of 95.5%. Despite the fluctuations in the sulfide concentration in the wastewater, the performance of the biological covers remained constant during the entire period of the study. The analysis of the different forms of sulfur accumulated in the peat beds allowed the understanding of the mechanisms involved in H2S removal. The high amount of sulfate demonstrated that the conditions were favorable to the biological oxidation of H2S. The addition of Fe3+ increased the formation of insoluble ferrous monosulfide (FeS) and pyrite (FeS2). The plants seemed to convert sulfate into elemental and organic sulfur.

Air Pollution↗
PubMed1992

The influence of peat extract on the seminiferous epithelium of mouse testes.

Because of the interest in the peat extract as a potential therapeutic agent, its effect on the seminiferous epithelium cells was studied. Adult male mice were intraperitoneally injected with peat extract during 34 days. At intervals equal to the duration of the cycle of the seminiferous epithelium (every 8.5 days), gametogenic cells were quantitatively analysed. It was revealed that the peat extract causes a decrease in the production of the A1 spermatogonia, and as a result a decrease in the intensity of spermatogenesis. Besides, in some individuals disturbances of meiosis took place, leading to an increased degeneration of pachytene spermatocytes and formation of diploid spermatids.

Animals↗
PubMed2004

[Vertical distribution character of nutrient elements in peat of Sanjiang Plain].

Based on the methods of sampling in winter and dividing soil layer on the site, the vertical distribution character of normal amount nutrient elements N, P, Mg, Ca, Fe and nutrient trace elements Cu, Zn, Mn, B in peat of river bed-flood land and valley depression land in the Sanjiang Plain was studied systematically. The results showed that TN was accumulated in surface layer of peat, and TP was accumulated in root layer. The contents of TN and TP were decreased with the section depth increasing. Zn, Mn, B, Mg and Fe were gathered in root layer and accumulated sharply in gley horizon of silt sub-clay, and the content of Ca was regular relatively in each layer of section. There were close correlations among some nutrient elements in peat section.

Calcium↗
PubMed2006

Bionomics studies of Mansonia mosquitoes inhabiting the peat swamp forest.

The present study was conducted in the years 2000-2002 to determine the bionomics of Mansonia mosquitoes, vectors of nocturnally subperiodic Brugia malayi, inhabiting the peat swamp forest, "Phru Toh Daeng", Narathiwat Province, Thailand. Fifty-four species of mosquitoes belonging to 12 genera were added, for the first time, to the list of animal fauna in the peat swamp forest. Mansonia mosquitoes were the most abundant (60-70%) by all collection methods and occurred throughout the year with a high biting density (10.5-57.8 bites per person-hour). Ma. bonneae was most prevalent (47.5%) and fed on a variety of animal hosts, including domestic cats, cows, monkeys, and man with a maximum biting density of 24.3 bites per person-hour in October. The infective bites were found for the first time in Ma. annulata collected at Ban Toh Daeng (13 00-14 00 hours) and also Ma. bonneae at forest shade (16 00-17 00 hours) and in a village (20 00-21 00 hours) with rates of 0.6, 1.1 and 1.0%, respectively. The biting activities of these two species occurred in both the day and night time, with two lower peaks at 10 00 hours (18.5 bites per person-hour) and 13 00-15 00 (8.5-10.0 bites per person-hour) hours, but the highest peak was 19 00-21 00 hours (31.5-33.0 bites per person-hour) The biting activity patterns corresponded with the periodicity found in man and domestic cats and may play an important role in either transmission or maintenance of the filarial parasites in the peat swamp forest. The relative role of Ma. bonneae and Ma. uniformis in different environmental settings (primary swamp forest and open swamp) on the transmission of nocturnally subperiodic B. malayi merits further study.

Animals↗
PubMedDate not supplied

[High abundance of planctomycetes in anoxic layers of a Sphagnum peat bog].

The depth distribution of planctomycete abundance has been examined in six different sites of the Sphagnum peat bog in Bakchar, Tomsk oblast, Russia. In situ hybridization of peat with the fluorescently labeled oligonucleotide probes PLA46 and PLA886, reported to be group-specific for representatives of the phylum Planctomycetes, revealed two distinct population maxima of these bacteria in all of the profiles examined. The first population maximum was detected in the uppermost, oxic layer of the bog profile, while the second maximum was located at a depth of 30 cm below the water table level. The population sizes of planctomycetes in the uppermost layer and at a depth of 30 cm were of the same order of magnitude and comprised 0.5-1.5 x 10(7) and 0.4-0.7 x 10(7) cells per g of wet peat, respectively. Only 25-30% of the total number of planctomycete cells in the anoxic layer could be detected if the probe PLA886, whose target specificity is restricted to taxonomically characterized aerobic planctomycetes of the genera Gemmata, Planctomyces, Pirellula, and Isosphaera, was used alone. Other planctomycete cells in this layer were detected only with the probe PLA46, which possesses a much wider scope. This suggests the affiliation of these organisms with a yet undescribed phylogenetic subgroup within the Planctomycetes.

Anaerobiosis↗
PubMed1989

[Peat poultices in the treatment of parodontal diseases].

For an assessment of the therapeutic effectiveness of peat poultices in parodontal diseases in 156 patients of either sex aged 24-68 years the authors used the gingival index, Suleus Fluid Rate, selective cytometric examination of salivary sediment and electrothermometric testing of the gingiva before and after this treatment. Moreover, after the treatment the patients answered an inquiry for expressing their opinion on the course and effectiveness of peat treatment. The difference test used in the calculations demonstrated statistically significant differences before and after the treatment with respect to the gingival index and Suleus Fluid Rate. Statistically significant differences were found also between the values of the leucocyte index and the keratinization index before and after peat treatment. The opinions of the patients were mostly positive.

Adult↗
PubMedDate not supplied

[Production of soy bean inoculants. Behavior of supports based on peat from Tierra del Fuego sterilized by vapor and ethylene oxide].

The survival of Rhizobium japonicum was studied in neutralized and sterilized peats from Ushuaia and Rio Grande. The carriers were sterilized by ethylene oxide and by autoclaving. Similar counts for Rhizobium (5 x 10(8) cel/g) were obtained in peat-cultures sterilized by both methods, after eight months. A good nodulation and nitrogen fixation capacity was observed with inoculated soybean plants. Using the strain Rhizobium japonicum E-45, no appreciable difference in symbiotic effectiveness was found between the inoculants prepared with the two peats.

Argentina↗
PubMed1995

The effect of feeding piglets up to the 100th day of their life with peat preparation on their growth and physiological and biochemical indices.

The experiment was carried out on a group of 300 piglets. During experiment the effect of supplementation with peat preparation coming from different charges on productivity, selected productive and biochemical indices was examined. All these indices were compared with a negative and positive control. A positive effect of supplementation with peat preparation in amount of 300 mg/kg of mixture on body weight increase and physiological and biochemical indices was found. The examined peat preparation coming from different charges demonstrated different effect which shows that it was not an entirely homogeneous material.

Aging↗