Sulfate reduction and diffusion in sediments of Little Rock Lake, Wisconsin

Urban, Noel R.; Brezonik, Patrick L.; Baker, Lawrence A.; Sherman, Leslie A.

doi:10.4319/lo.1994.39.4.0797

Cited by 105 publications

(61 citation statements)

References 67 publications

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“…The observation that SO 4 2 -diffusion accounted for <10% of the SO 4 2 -demand at MB during the springsummer transition (May to July), and a larger proportion (30 to 50%) during early spring and late fall (Fig. 7), was similar to an earlier report in which depth-integrated benthic SR exceeded modeled diffusive influx of SO 4 2 - (Urban et al 1994). The balance of the SO 4 2 -needed to fuel SR can only be supplied by advective transport and/or by S-recycling.…”

Section: Sulfate Concentrationsupporting

confidence: 77%

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Marvin-DiPasquale

Boynton²,

Capone³

2003

Mar. Ecol. Prog. Ser.

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Seasonal and interannual controls of benthic sulfate reduction (SR) were examined at 3 sites (upper [UB], mid- [MB] and lower [LB] bay) along the Chesapeake Bay central channel, from early spring through fall, for 6 yr (1989 to 1994). The combined influences of temperature, sulfate, organic loading and bioturbation affected seasonal SR rates differently in the 3 regions. Consistently low SR rates at UB resulted from low overlying-water sulfate concentrations and the dominance of refractory organic terrestrial material. Combined seasonal variation in temperature and sulfate accounted for 50% of the annual variability in 0 to 2 cm depth interval SR rates, while sediment organic content had no significant seasonal influence. In contrast, MB and LB sites had high rates of SR fostered by high levels of overlying water SO 4 2 -and organic input dominated by labile phytoplankton detritus. New organic loading (measured as chl a) stimulated 0 to 2 cm SR during spring at both sites. Combined organic quantity (as particulate C and/or N) and temperature accounted for >75% of the variability in 0 to 2 cm SR at MB during spring and fall. Molecular diffusion supplied 25 to 45% of the SO 4 2 -needed to fuel 0 to 12 cm depth interval SR at MB, with the balance presumably supplied by S-recycling. Interannual differences in summertime SR rates were linked to the extent of freshwater flow during spring, with high-flow years associated with high SR rates at UB and MB, and low rates at LB. The negative trend between benthic SR and river flow at LB may result from the upestuary transport of senescing organic matter in bottom water, which increases in the lower reach of the estuary with increasing freshwater inflow.

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Section: Sulfate Concentrationsupporting

confidence: 77%

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Marvin-DiPasquale

Boynton²,

Capone³

2003

Mar. Ecol. Prog. Ser.

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“…Although other factors may contribute to this difference, as discussed for the offset in modeled and measured AOM rates above, the difference was much larger than for AOM. Indeed, it seems typical for freshwater sediments that directly measured rates of SR substantially exceed those supported by diffusion, and this has been attributed to rapid reoxidation of sulfide (Urban et al 1994). The mechanisms of reoxidation could involve cycles of abiotic oxidation of sulfide to elemental sulfur with Fe(III) oxide coupled to disproportionation of sulfur to sulfide and SO 2{ 4 (Thamdrup et al 1993).…”

Section: Discussionmentioning

confidence: 99%

Anaerobic oxidation of methane in an iron‐rich Danish freshwater lake sediment

Nordi

Thamdrup

Schubert

2013

Limnology & Oceanography

146

123

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Freshwater systems are identified as one of the main natural methane sources, but little is known about the importance of anaerobic oxidation of methane (AOM) in these systems. We investigated AOM in a lake sediment characterized by a high reactive iron content, normal sulfate concentrations in the bottom water (, 250 mmol L 21 ), and a relatively deep sulfate penetration of , 14 cm, which facilitated the spatial resolution of the zones of methane production and consumption. Methane concentrations, d 13 C methane profiles, and directly measured and modeled AOM rates all consistently demonstrated methane consumption throughout the anoxic, nitrate-free, Fe(III)-and sulfate-containing zone, oxidizing , 90% of the diffusive methane flux. Thus, the concentration gradient of methane was steepest at the base of the Fe(III) and sulfate zone and decreased strongly toward the sediment surface; while d 13 CH 4 increased from , 280% in the methanogenic zone to 248% in the surface sediment. Direct measurements demonstrated AOM activity throughout the Fe(III) and sulfate zone. AOM rates peaked at sulfate concentrations below 3 mmol L 21 , which suggests a possible coupling of AOM to the reduction of more crystalline Fe(III) oxides. Alternatively, AOM could be coupled to sulfate reduction, which was in turn supported by a cryptic sulfur cycle coupled to Fe(III) reduction. Our results show that AOM can substantially reduce methane emission from freshwater sediments, and the finding of AOM at sulfate concentrations , 3 mmol L 21 suggests that AOM could be of greater importance in freshwater systems, and in ancient low-sulfate oceans, than was previously appreciated.

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“…Increasing diffusive fluxes of nutrients and inorganic carbon with increasing water depth have been reported previously by Carignan and Lean (1991) for a mesotrophic lake, but 13 Porewater profiles from dialysis samplers Sherman et al (1994) did not observe such a phenomenon in an oligotrophic lake. In L. Vechten oxygen consumption rates are higher in pelagic than in littoral sediments (Sweerts et al, 1991), but diffusive fluxes of sulfate and nitrate have been reported to be similar in littoral and pelagic sediments (Cook et al, 1986Urban et al, 1994).…”

Section: Spatial Variationmentioning

confidence: 98%

Solute transfer across the sediment surface of a eutrophic lake: I. Porewater profiles from dialysis samplers

1997

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Porewater profiles often are used to identify and quantify important biogeochemical processes occurring in lake sediments. In this study, multiple porewater profiles were obtained from two eutrophic Swiss lakes using porewater equilibrators (peepers) in order to examine spatial and seasonal trends in biogeochemical processes. Variability in profile shapes and concentrations was small on spatial scales of a few meters, but the uncertainty in calculated diffusive fluxes across the sediment surface was, on average, 35%. Focusing of Fe and Mn oxides toward the lake center resulted in systematic increases in porewater concentrations and diffusive fluxes of Fe 2+ and Mn 2+with increasing water depth; these fluxes are postulated to be regulated by the pH-dependent dissolution of reduced-metal phases. Despite higher concentrations of inorganic carbon, NH 4 + , Si and P in pelagic compared to littoral sites, diffusive fluxes of these substances across the sediment surface increased only slightly or not at all with increasing water depth. Porewater profiles did reveal temporal changes in Fe 2+ , Mn 2+ , Ca 2+ and Mg 2+ that were an indirect result of the large, seasonal changes in seston deposition, but no clear seasonal variations were found in diffusive fluxes of nutrients across the sediment surface. The intense mineralization occurring at the sediment surface was not reflected in the porewater profiles nor in the calculated diffusive fluxes. Calculated diffusive fluxes across the sediment surface resulted from decomposition occurring primarily in the top 5-7 cm of sediment. Diffusive fluxes from this subsurface mineralization were equal to the solute release from mineralization occurring at the sediment-water interface. Buried organic matter acts as a memory of previous lake conditons; it will require at least a decade before reductions in nutrient inputs to lakes fully reduce the diffusive fluxes into the lake from the buried reservoir of organic matter.

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Sulfate reduction and diffusion in sediments of Little Rock Lake, Wisconsin

Cited by 105 publications

References 67 publications

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Benthic sulfate reduction along the Chesapeake Bay central channel. II. Temporal controls

Anaerobic oxidation of methane in an iron‐rich Danish freshwater lake sediment

Solute transfer across the sediment surface of a eutrophic lake: I. Porewater profiles from dialysis samplers

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