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1.
Time-dependent uptake of 35S]SO42? from surface water overlying cores of peat occurred by passive diffusion along a concentration gradient set up by SO42? metabolism in the peat. The limiting rate constant of SO42? uptake was related to concentration according to Michaelis-Menten kinetics. In peat cores taken from an area of mire submerged by surface water biologically-mediated uptake began immediately. But in cores taken from an adjacent area where the water table was about 5 cm below the peat surface, SO42? metabolism was slower and developed after a lag of about 2.3–4.0 days. Only about 2.2% of [35S]SO42? taken up by peat cores remained in the water-soluble pool, while about 11% was associated with acid-volatile H2S. Most of the remainder appeared to be incorporated into organic matter. Less than 0.3% was released as H2S into the gas phase. The experimental results are consistent with a flux into the peat of 3.28–7.71 g S m?2yr?1, comparable with 4.76–6.06 g S m?2yr?1 indicated by measurements of S content and age of the peat. The results suggest that uptake and metabolism of dissolved SO42? may be the major route of S incorporation into peat.  相似文献   

2.
Odors, such as the malodorous and toxic hydrogen sulfide (H2S), are released during leachate collection, storage, and treatment. A full-scale biofilter was applied to treat H2S emitted from a leachate equalization basin in a sanitary landfill site. The inlet concentration of H2S was 26.3?C213.0?mg?m?3. In steady state, total removal efficiency was over 90?% in summer and over 80?% in winter. The maximum elimination capacity achieved 9.1?g?m?3?h?1 at a loading rate of 10.5?g?m?3?h?1. The biofilter was effective at reducing H2S. Factors on the level of H2S inlet concentration and performance of the biofilter were investigated. The H2S inlet load and removal efficiency relied on ambient and biofilter temperature, respectively. The water containing rate and relative humidity presented seasonal variation, according to which the interval period of irrigation could be optimized. The main product of H2S degradation was sulfate, and sulfur also could be observed from the biofilter. Spatial and temporal shifts in bacterial community composition in the biofilter were determined by polymerase chain reaction-denaturing gradient gel electrophoresis followed by DNA sequence analysis. The present study revealed a correlation between biofilter performance and bacterial community structure, especially in a real application case.  相似文献   

3.
About 90% of total S in a peat profile from a valley mire was associated with organic matter, and in the anaerobic zone, most of the remaining S could be distilled as H2S (steam-volatile H2S). [35S]SO2?4 was rapidly incorporated into both organic and steam-volatile H2S pools, with preferential labelling of organic matter at the surface of the peat (? 10 cm depth) and of steam-volatile H2S at greater depth (? 10 cm depth). Less than 2% of the steam-volatile H2S could be accounted for as H2S in solution in the pore water, and evidence suggesting FeS as the source of this fraction is presented. Less than 2% of the total S in the profile was present as FeS2 or S°, and S2O2?3 and S4O2?6 could not be detected. Measurements of total S content of the peat and estimates of the age of the deposit indicate a rate of S accumulation of 4.76–6.06 g S m?2yr?1. The results are discussed in the context of the mechanisms of S transformations and uptake by other mire systems.  相似文献   

4.
A vertically moving biofilm system (VMBS) was developed to treat wastewater. In this system, the biofilm grows on a biofilm module consisting of plastic media that is vertically and repeatedly moved up into the air and down into the water. The objectives of this study were to investigate the oxygen transfer efficiency and industrial wastewater treatment performance of the VMBS. The oxygen transfer coefficient (K L a) depended on the movement frequency (n) of the biofilm module and was proportional to n 1.67. K L a values measured were within the range of 0.0001 to 0.0027 s-1. The VMBS exhibited good carbonaceous removal when treating industrial wastewater produced in a factory manufacturing synthetic fibres. Removal efficiency of filtered chemical oxygen demand (COD) and biological oxygen demand (BOD5) was up to 93.2 and 97.9%, respectively. The volumetric removal rates of filtered COD and BOD5 reached 1320 g COD m-3 day-1 and 700 g BOD5 m-3 day-1. The areal organic removal rates, based on the surface area of the biofilm substrata, were 16 g BOD5 m-2 day-1 and 39 g COD m-2 day-1. No clogging occurred during the experiment. The mean areal biofilm mass increased with increasing the mean areal BOD5 removal rate. The new biofilm process has such advantages as high carbonaceous oxidation, energy saving, simpleconstruction and easy operation for industrial wastewater treatment.  相似文献   

5.
The biofilter system containing tire-derived rubber particle (TDRP) filter media was utilized to treat the odorous gas contaminant, hydrogen sulfide, in consideration of the economic advantage of reusing discarded tire materials and the high potential of TDRP media for biofilm attachment. The pilot-scale system having 0.38 m3 of bed volume operated with synthetic hydrogen sulfide gas on continuous basis from a range of 0.34 to 1.15 m3/min. This bioreactor system achieved over 94% removal efficiency at 20?C90 ppm of inlet H2S concentration while operating in 20?C67 s of empty bed retention time, indicating that overall effective operation was performed at mass loading rates of H2S ranging from 19.6 to 28.5 g H2S/(m3?h). It was apparent by the effectiveness of the system??s performance that this system had the capability to effectively remove hydrogen sulfide with high efficiency over a range of concentrations. A maximum elimination capacity was not found for the biofilter during this study, which tested loading rates between 0 and 30 g H2S/(m3?h).  相似文献   

6.
 Rates of methane uptake were measured in incubation studies with intact cores from adjacent fenland peats that have been under arable management and woodland management for at least the past 30 years. On two separate occasions the woodland peat showed greater rates of uptake than the arable peat. These rates ranged from 23.1 to 223.3 μg CH4 m–2 day–1 for the woodland peat and from 29.6 to 157.6 μg CH4 m–2 day–1 for the arable peat. When the peats were artificially flooded there was a decrease in the rate of methane oxidation, but neither site showed any net efflux of methane. 15N isotopic dilution was used to characterise nitrogen cycling within the two peats. Both showed similar rates of gross nitrogen mineralisation (3.58 mg N kg–1 day–1, arable peat; 3.54 N kg–1 day–1, woodland peat) and ammonium consumption (4.19 arable peat and 4.70 mg N kg–1 day–1 woodland peat). There were significant differences in their inorganic ammonium and nitrate pool sizes, and the rate of gross nitrification was significantly higher in the woodland peat (4.90 mg N kg–1 day–1) compared to the arable peat (1.90 mg N kg–1 day–1). These results are discussed in the light of high atmospheric nitrogen deposition. Received: 1 December 1997  相似文献   

7.
The gaseous streams containing hydrogen sulphide (H2S) mixed with nitrogen gas (N2) (H2S, 0.00145 mol L-1), H2S mixed with liquefied petroleum gas (LPG) and refinery fuel gas were evaluated, in batch operation, in a bubbled column reactor for desulphurization using ferric sulphate as an oxidant. Further, the ferrous sulphate produced in the process of oxidation is biologically oxidized to ferric sulphate using biomass enriched with Thiobacillus ferrooxidans-JSPR1 in flask culture experiments. In all the cases, the gases were bubbled into the biologically generated ferric sulphate (from ferrous sulphate solution) for the oxidation of H2S. The results indicate that0.00426 mol L-1 of ferric ions are required for reacting with0.00145 mol L-1 of H2S in a gaseous stream containing mixture of N2 and H2S. A concentration of 0.00447 mol L-1 of ferric ions is needed for oxidation of 0.00145 mol L-1 of H2S mixed with LPG. Similarly, the refinery fuel gas containing 0.0031 mol L-1 of H2S requires 0.00428 mol L-1 of ferric ion for effective desulphurization. The ratio of moles of H2S reacted to moles of Fe2+ produced at optimal condition was 0.533, 0.516, 0.510, respectively, for nitrogen mixed H2S, LPG mixed H2S and refinery fuel gas containing H2S. The removal of H2S from these gaseous streams was more than 98%sulphate produced in the process could be biologically oxidized to ferric sulphate with an efficiency of 98%, using shake flask culture experiments. Based on flask culture experiments for biooxidation of commercial ferrous sulphate to generate ferric sulphate, the biokinetic constants viz. yield coefficient y, maximum specific growth rate constant μmax and half saturation rate constant K s were evaluated. The yield coefficient was found to be 0.112 while μmax and K s were observed to be 0.1686 hr-1 and 187.9 mg L-1, respectively. The evaluation of biokinetic constants for bio-oxidation of ferrous sulphate generated during the scrubbing of refinery fuel gas containing H2S indicated the value of μmax and K s as 0.1426 hr-1 and 205 mg L-1, respectively. The value of yield coefficient in this real system was found to be 0.102.  相似文献   

8.
Kang  H.  Freeman  C. 《Water, air, and soil pollution》2002,141(1-4):263-272
Methane emissions from an acidic bog and a forested swamp in north Wales, U.K., were measured over a 12 month period. Along with the emission, hydrochemistry (DOC, SO4 2- and NO3 -) and physical factors (temperature, water table level) were determined. At the bog site, the methane emission ranged from 0.15 mg m-2 day-1 to 6.39 mg m-2 day-1, having two peaks in spring and late summer. In contrast, high emission was observed in October (38.95 mg m-2 day-1) and November (75.37 mg m-2 day-1)at the swamp site, which is concurrent with leaf litter production and high DOC concentrations. During the remaining months, the flux varied between –1.33 mg m-2 day-1 and 3.05 mg m-2 day-1. Correlation analyses showed that the methane emission from the acidic bog had a positive correlation with soil temperature, and negative correlations with sulfate and nitrate concentrations in the pore-water. However, a correlation with water table level was absent. Methane emission from the swamp exhibited a negative correlation with sulfate concentration. Our results confirm that methane emissions vary substantially between different types of wetlands, and suggest that under certain conditions, hydrochemistry may be a more critical controlling variable for methane emissions than temperature and water table level.  相似文献   

9.
To improve domestic wastewater treatment for total nitrogen (TN) removal, a full-scale constructed wetlands combining an artificially aerated vertical- (AVCW) and a horizontal-flow constructed wetland (HCW) was completed in July 2007. The system covered a total area of 7,610?m2. From 2 July 2007 to 7 August 2008, the treatment capacity was 2,076?m3?day?1 with an aeration quantity of 7,400?m3?day?1. The system effectively reduced the average annual output of BOD5 (52.0?%), NH4?CN (58.41?%), and TP (41.61?%), although the percentage reductions of other pollutants, including chemical oxygen demand (34.1?%), suspended solid (38.9?%), and TN (31.05?%) were lower. The purpose of the HCW was for denitrification of the effluent from the AVCW, and annual average of 34.27?% of NO3?CN was removed compared with the reading at the AVCW outlet. With hydraulic loading increased to 4,152?m3?day?1 from 9 September to 23 November 2007, the removal rate for NO3?CN from the HCW decreased substantially from 48.80 to 18.86?%. The total removal rates of NH4?CN showed significant positive correlation with DO content in the AVCW and with total TN removal rates for the combined system (P?<?0.05). The study indicated that, even with limited artificial aeration, nitrification was very effective for NH4?CN removal.  相似文献   

10.
The present work discusses the startup and operation of different biotrickling filters during the simultaneous removal of NH3, H2S, and ethyl mercaptan (EM) for odor control, focusing on (a) the impact of pH control in the stability of the nitrification processes during reactor startup and (b) the crossed effects among selected pollutants and their by-products. Two biotrickling filters were packed with poplar wood chips (R1 and R2A), while a third reactor was packed with polyurethane foam (R2B). R2A and R2B presented a pH control system, whereas R1 did not. Loads of 2?C10?g N?CNH3 m?3?h?1, 5?C16?g S?CH2S m?3?h?1, and 1?C6?g EM m?3?h?1 were supplied to the bioreactors. The presence of a pH control loop in R2A and R2B proved to be crucial to avoid long startup periods and bioreactors malfunctioning due to biological activity inhibition. In addition, the impact of the presence of different concentrations of a series of N species (NH 4 + , NO 2 ? , and NO 3 ? ) and S species (SO 4 2? and S2?) on the performance of the two biotrickling filters was studied by increasing their load to the reactors. Sulfide oxidation proved to be the most resilient process, since it was not affected in any of the experiments, while nitrification and EM removal were severely affected. In particular, the latter was affected by SO 4 2? and NO 2 ? , while nitrification was significantly affected by NH 4 + . The biotrickling filter packed with polyurethane foam was more sensitive to crossed effects than the biotrickling filter packed with poplar wood chips.  相似文献   

11.
Zou  Juan  Guo  Xuesong  Han  Yunping  Liu  Junxin  Liang  Hanwen 《Water, air, and soil pollution》2012,223(2):889-900
Constructed wetlands are recognized as a reliable technology for rural wastewater treatment. However, conventional constructed wetlands face problems with low pollutant removal efficiency and limited oxygen transfer capability. Therefore, a novel vertical flow constructed wetland (VFCW) system with drop aeration was developed in this study. Two pilot-scale vertical flow constructed wetlands of 0.75 m2 each were constructed with the same dimensions and configuration but different media, one of which (named as CW1) was filled with a 1:1 mixture (by weight) of zeolite and dolomite and the other (named as CW2) with the same zeolite only. The oxygen transfer capability of a multilevel two-layer drop aeration device, organics and nitrogen removal of CW1 and CW2, and pollutant distribution along the depths of CW1 and CW2 in different operational phases were studied. The results demonstrated that compared with the direct drop aeration process, the multilevel, two-layer drop aeration device supplied 2–6 mg/L higher dissolved oxygen per meter of drop height, and after installation of the six-level, two-layer drop aeration devices, the 5-day biochemical oxygen demand removal load was improved from 8.1 to 14.2 g m−2 day−1 for CW1. With regard to the different filter media, nitrogen removal was improved by the adsorption of zeolite in the first year, with 5–36% higher NH4+–N removal efficiency of CW2 compared with that in CW1. Since it did not have a significant positive effect on phosphate removal, dolomite can be replaced by zeolite. The chemical oxygen demand removal mainly took place in the upper 15-cm filter layer in different operational phases, while nitrogen distribution along the depths of the VFCWs was different in different operational phases. In addition, as no operational problems occurred, the vertical flow constructed wetland system with drop aeration is an appropriate alternative for rural wastewater treatment, with numerous advantages of low capital and operation costs, no energy consumption, easy maintenance, high hydraulic loading rate, high pollutant removal efficiency, and no clogging.  相似文献   

12.
Abundant production of organic matter that decomposes slowly under anaerobic conditions can result in substantial accumulation of soil organic matter in wetlands. Tedious means for estimating production and decomposition of plant material, especially roots, hampers our understanding of organic matter dynamics in such systems. In this paper, I describe a study that amended typical estimates for both production and decomposition of organic matter by measuring net flux of carbon dioxide (CO2) over the peat surface within a conifer swamp, a sedge-dominated marsh, and a bog in the Appalachian Mountain region of West Virginia and western Maryland, USA. The sites are relatively productive, with net primary production (NPP) of 30 to 82.5 mol C m?2 yr?1, but peat deposits are shallow with an average depth of about 1 m. In summer, all three sites showed net CO2 flux from the atmosphere to the peat during the daytime (?20.0 to ?30.5 mmol m?2 d?1), supported by net photosynthesis, which was less than net CO2 flux from the peat into the atmosphere at nighttime (39.2 to 84.5 mmol m?2 d?1), supported by ecosystem respiration. The imbalance between these estimates suggests a net loss of carbon (C) from these ecosystems. The positive net CO2 flux seems to be so high because organic matter decomposition occurs throughout the peat deposit — and as a result concentrations of dissolved inorganic carbon (DIC) in peat pore waters reached 4,000 Μmol L?1 by late November, and concentrations of dissolved organic carbon (DOC) in peat pore waters reached 12,000 Μmol L?1. Comparing different approaches revealed several features of organic matter dynamics: (i) peat accretion in the top 30 cm of the peat deposit results in a C accumulation rate of about 15 mmol m?2 d?1; however, (ii) the entire peat deposit has a negative C balance losing about 20 mmol m?2 d?1.  相似文献   

13.
Abstract

A laboratory study was conducted to investigate whether the Zn‐Na acetate solution, used for trapping H2S in the Johnson‐Nishita method (1952), could be used to quantitatively determine 35S and 32S in the same trapping solution, as the Zn‐Na acetate solution allows more sensitive S determination using methylene blue than does the bismuth sulphide colour development of H2S trapped in NaOH solution. Results obtained using the Zn‐Na acetate solution were variable compared with those obtained from the normal procedure of using NaOH as the H2S trapping solution, indicating that the Zn‐Na acetate solution was unsuitable, probably because of the rapid transformation of H2S to water‐insoluble ZnS.

The applicability of methylene blue development for H2S trapped in NaOH solution was also investigated. Results showed that 32S could be determined quantitatively provided methylene blue colour development was conducted less than 30 minutes after the removal of H2S‐trapping NaOH solution from the Johnson‐Nishita digestion‐distillation unit. A delay of more than 30 minutes caused a significant linear reduction (R2 = 0.86 ‐ 0.92***) in methylene blue colour, indicating that H2S in NaOH solution was readity: oxidized to other S forms which did not undergo methylene blue development.

Toluene and dioxane were compared as liquid scintillants for assaying 35S activity trapped as H2S in either NaOH or Zn‐Na acetate solution before and after methylene blue development. Before colour development, toluene improved the counting efficiency of 35S in NaOH solution by 23 to 27%. After colour development, toluene improved the counting efficiency of both NaOH and Zn‐Na acetate solutions.  相似文献   

14.
Anthropogenic and biogenic high molecular weight (C12–C32) hydrocarbons (HC) were deposited from the atmosphere in association with both wet and dry deposition. Wet deposition generally removes HC at a faster rate (22 to 670 μg m?2 day?1) than dry deposition (4 to 189 μg m?2 day?1). However, due to longer periods during which dry deposition occurred, the removal of atmospheric HC by wet and dry deposition is almost equal during this sampling period. Atmospheric HC concentrations ranged from 0.8 to 4.1 μg m?3 and show no simple relationship to wet or dry deposition rates. Large variabilities in deposition rates for individual events were found, but long-term average deposition was relatively constant.  相似文献   

15.
Depth profiles of total S, organic S, soluble SO 4 2? -S, FeS, and FeS2 were characterized for Sphagnum-derived peat cores collected from 9 sites. Marcell S-2 Bog (MN), Tamarack Swamp (PA), Cranesville Swamp (MD/WV), and Big Run Bog (WV) receive water from precipitation and upland runoff; atmospheric S deposition is 13, 47, 54, and 114 mmol m?2, yr?1, respectively. McDonald's Branch Swamp (NJ) is predominantly groundwater fed. Tub Run Bog (WV) and Allegheny Mining Bog (MD) receive augmented SO 4 2? inputs through acid coal mine drainage. Jezerní slat' and Bo?í Dar Bog in Czechoslovakia receive atmospheric S inputs of 33 and 243 mmol m?2 yr?1, respectively. In the peat from all sites except Allegheny Mining Bog, where the substantially augmented SO 4 2? input was reflected in an unusually high dissolved SO 4 2? pool in the surface peat, organic S (probably mostly carbon bonded S) was the dominant S fraction; FeS2 was generally the dominant inorganic S fraction. Subsurface peaks in total S, organic S and FeS2-S in peat from the runoff water fed sites were interpreted as indicative of depth-dependent patterns in S reduction/oxidation and in S immobilization/mineralization. Unless SO 4 2? inputs to a site are tremendously augmented (e.g., Allegheny Mining Bog), the rapid turnover of the dissolved SO 4 2? pool combined with the relative stability of the other inorganic and organic S pools, apparently functions as an effective buffer against site differences in S inputs, leading to a general similarity in vertical S profiles in the peat deposits.  相似文献   

16.
While developing a low-sulphate system combining indirect chromate-reduction by biologically-produced hydrogen sulphide and direct biological chromate-reduction to treat chromate-bearing waters, the aim of the present work was to evaluate the influence of sulphate and H2 starvation on chromate reduction. Chromate-reduction was performed under continuous-feed conditions in a fixed-film column bioreactor originally inoculated with a bacterial consortium containing Desulfomicrobium norvegicum, and fed with H2. With 500 mg l?1 of sulphate in the feed solution, total chromate-reduction was observed in the effluent whereas sulphate-reduction was strongly decreased, as also confirmed by measurements of isotopic ratios for sulphur. In the absence of sulphate, a chromate-reduction activity was still observed but was lower than in the presence of sulphate, and chromate-reduction was H2-dependent. Molecular biology techniques revealed the composition of the bacterial population in the effluent. D. norvegicum together with other micro-organisms of the Bacteria domain were detected. They include members related to the genera Acinetobacter, Acetobacterium and Rhodocyclus. Even when sulphate-reduction was strongly decreased, the presence of sulphate enhances the efficiency of the H2-dependent chromate-reduction. A H2- and CO2-consuming bacterial population may be used in a globally autotrophic process to reduce chromate at low sulphate concentration, thus avoiding excess sulphide production.  相似文献   

17.

The performance of lab-scale compostbiofilters for the purification of waste gasescontaining high (>70 mg m-3) ammoniaconcentrations was studied. When using fresh compostmaterial, no effect of inoculating the compostmaterial with a nitrifying culture was observed sincehigh elimination capacities (up to 350 gNH3 m-3 d-1) were obtained in both theinoculated and the non-inoculated biofilter. Due tothe physico-chemical interaction of NH3 with thecompost material at the start of the experiment, nomicrobiological start-up period was observed and highremoval efficiencies were obtained from the first dayon. Next to this, no NH3-toxicity was observedeven at concentrations up to 550 mg NH3 m-3.About 50% of the NH3-removal was found to benitrified, while the other 50% remained in thebiofilter as NH +4 . As a result of this, noacidification of the carrier material was observed andNH4NO3 accumulated in the biofilter. Due toosmotic effects, however, a complete inhibition innitrification and NH3-removal was obtained at ameasured NH4NO3-concentration in the compostmaterial of 6–7 g N kg-1, corresponding to acumulative NH3-removal in the biofilter of ±6000 g m-3. Finally, it was illustrated that theremoval of the odorant dimethyl sulfide (Me2S) ina Hyphomicrobium MS3-inoculated compostbiofilter is completely inhibited due toNH3-toxicity at a waste gas concentration of 100 mg NH3 m-3. Next to this, theNH +4 - and NO ?3 -concentrations inthe compost material that were shown to inhibit thenitrification, also strongly affected theMe2S-degrading activity of Hyphomicrobium MS3.

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18.
A mixed provenance Sitka spruce plantation, planted in 1986 on a drained deep peat, has been exposed to 6 different simulated mist treatments in 4 replicated blocks since 1996. Treatments provided N and/or S at a concentration of 1.6 mol m?3, supplying ca. 50 kg S and/or N ha?1 yr?1 as N (NH4NO3), S (Na2SO4), NS Acid (NH4NO3 + H2SO4 at pH 2.5), 2NS Acid (double dose by application at twice frequency), a control treatment supplied with additional rainwater only and a 'no treatment' set of plots. Throughfall, preserved with thymol in the field, was collected using gutters with a surface area of 1 m2 in all the replicate plots, and was analysed for all major ions. Prior to treatment in 1999, S deposition in throughfall exceeded that in rain because of dry deposition of SO2 and SO4 2? to the canopy; NH4 + and NO3 ? ions were both retained in the canopy. During treatment, only 20–40% of the applied N in the high-N treatments was retained in the canopy. Acidity in the applied mist was partly neutralised by the canopy, but not primarily through exchange of base cations, leading to the conclusion that weak organic acids, in solution or in situ in the canopy, contributed to the buffering of the H+ ion deposition in the acid treatments.  相似文献   

19.
Summary Lumbricus terrestris L. juveniles confined in nylon mesh bags grew at mean rates of 6–12 mg ind–1 day–1 in reclaimed peat grassland soil, while the growth rates of Aporrectodea caliginosa (Sav.) juveniles were 1.5–2.1 mg ind–1 day–1. Earthworm population densities exceeding 700 m2 had become established within 1 year adjacent to sods transplanted from an old pasture, while microplots enclosed in nylon mesh cages had mean population densities of 318–408 earthworms m–2 and biomass of 89–111 g m–2 3–4 1/2 years after inoculation. Herbage yields were 25% greater in the 2nd year and 49% greater in the 3rd year in earthworm-inoculated microplots which received an annual application of cattle slurry compared with similarly fertilized, non-inoculated cages.Dedicated to the late Prof. Dr. M.S. Ghilarov  相似文献   

20.
Rates of organic carbon mineralization (to CO2 and CH4) vary widely in peat soil. We transplanted four peat soils with different chemical composition into six sites with different environmental conditions to help resolve the debate about control of organic carbon mineralization by resource availability (e.g. carbon and nutrient chemistry) versus environmental conditions (e.g. temperature, moisture, pH). The four peat soils were derived from Sphagnum (bog moss). Two transplant sites were in mid‐boreal Alberta, Canada, two were in low‐boreal Ontario, Canada, and two were in the temperate United States. After 3 years in the field, CH4 production varied significantly as a function of peat type, transplant site, and the type–site interaction. All four peat soils had very small rates of CH4 production (< 20 nmol g?1 day?1) after transplant into two sites, presumably caused by acid site conditions (pH < 4.0). One peat soil had small CH4 production rates regardless of transplant site. A canonical discriminant analysis revealed that large rates of CH4 production (4000 nmol g?1 day?1) correlated with large holocellulose content, a large concentration of p‐hydroxyl phenolic compounds in the Klason lignin, and small concentrations of N, Ca and Mn in peat. Significant variation in rates of CO2 production correlated positively with holocellulose content and negatively with N concentrations, regardless of transplant site. The temperature response for CO2 production varied as a function of climate, being greater for peat formed in a cold climate, but did not apply to transplanted peat. Although we succeeded in elucidating some aspects of peat chemistry controlling production of CH4 and CO2 in Sphagnum‐derived peat soils, we also revealed idiosyncratic combinations of peat chemistry and site conditions that will complicate forecasting rates of peat carbon mineralization into the future.  相似文献   

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