Manganese Reduction in Oneida Lake, New York: Estimates of Spatial and Temporal Manganese Flux

1994 ◽  
Vol 51 (1) ◽  
pp. 185-196 ◽  
Author(s):  
Carmen Aguilar ◽  
Kenneth H. Nealson
Keyword(s):  
New York ◽  
Water Interface ◽  
Concentration Gradients ◽  
Oneida Lake ◽  
Direct Measurements ◽  
Photosynthetic Production ◽  
Tightly Coupled ◽  
Early Fall ◽  
Manganese Cycle

Manganese is a very reactive redox metal, which exhibits a strong annual cycle in Oneida Lake, New York. Different methods were used to measure Mn(II) fluxes from the sediments throughout the year: (1) estimates based on changes in porewater profiles, (2) direct measurements with in situ flux chambers, (3) concentration gradients into the sediment–water interface in laboratory-incubated cores, and (4) changes in hypolimnetic manganese inventories during stratification. In deep basins of the lake, high rates of Mn(IV) reduction, up to 2.1 mmol∙m−2∙d−1, were observed during the summer and early fall, with little reduction taking place during the rest of the year. In the shallow areas of the lake, where ferromanganese nodules and crusts are commonly found, there was little or no reduction throughout the year. The manganese cycle is tightly coupled to the carbon cycle, based on our findings, and has a significant role in the oxidation of organic carbon in the lake, derived from the high photosynthetic production and the bio-mass that collapses and reaches the sediment–water interface. Preliminary experiments with poisoned controls suggest that Mn(IV) reduction is the result of a combination of biological and abiological processes.

Mathematical Model Investigation of Far-Field Transport of Ocean-Dumped Sewage Sludge Related to Remote Sensing

1982 ◽  
Vol 14 (3) ◽  
pp. 33-39
Author(s):  
C Y Kuo
Keyword(s):  
New York ◽  
Sewage Sludge ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Approximate Model ◽  
Transport Processes ◽  
Far Field ◽  
New York Bight ◽  
Mean Current

An existing, three-dimensional, Eulerian-Lagrangian finite-difference model was modified and used to examine the far-field transport processes of dumped sewage sludge in the New York Bight. Both in situ and laboratory data were utilized in an attempt to approximate model inputs such as mean current speed, vertical and horizontal diffusion coefficients, particle size distributions, and specific gravities. Concentrations of the sludge near the sea surface predicted from the computer model were compared qualitatively with those remotely sensed.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

In situ arsenic speciation at the soil/water interface of saline-alkaline lakes of the Pantanal, Brazil: A DGT-based approach

2021 ◽  
pp. 150113
Author(s):  
José Lucas Martins Viana ◽  
Adriana Felix de Souza ◽  
Amauris Hechavarría Hernández ◽  
Lucas Pellegrini Elias ◽  
Carlos Eduardo Eismann ◽  
...  
Keyword(s):  
Soil Water ◽  
Arsenic Speciation ◽  
Water Interface ◽  
Alkaline Lakes

scholarly journals Spin Crossover in Nickel(II) Tetraphenylporphyrinate via Forced Axial Coordination at the Air/Water Interface

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4155
Author(s):  
Alexander V. Shokurov ◽  
Daria S. Kutsybala ◽  
Andrey P. Kroitor ◽  
Alexander A. Dmitrienko ◽  
Alexander G. Martynov ◽  
...  
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
High Spin State ◽  
Water Interface ◽  
Metal Centers ◽  
Axial Coordination ◽  
Vis Spectroscopy ◽  
Air Water Interface ◽  
Nickel Cation

Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)2, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer.

Performance of Indigenous, Exotic, and Hybrid Strains of Brook Trout (Salvelinus fontinalis) in Waters of the Adirondack Mountains, New York

1981 ◽  
Vol 38 (12) ◽  
pp. 1701-1707 ◽  
Author(s):  
Dwight A. Webster ◽  
William A. Flick
Keyword(s):  
New York ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Hybrid Vigor ◽  
Superior Performance ◽  
Adirondack Mountains ◽  
Wild Strains ◽  
Early Fall ◽  
Survival And Growth ◽  
Wild Trout

Eleven year-classes of wild, domestic, and wild × domestic hybrid strains of brook trout (Salvelinus fontinalis) were stocked in a 0.19-ha Adirondack pond. Comparative survival and growth were assessed upon drainage in early fall. Rearing native wild strains to maturity in a hatchery, or domestic strains in a natural environment, did not consistently or materially affect survival of progeny, suggesting that superior performance of wild strains was largely inherent. Interstrain hybrids of wild × domestic showed survivals equivalent to the wild parents, but hybrids of two Canadian strains gave evidence of heterosis in both survival and net yield. Supplementary observations in other waters also indicated that one strain (Assinica) may be less adaptable to Adirondack conditions than the other (Temiscamie).Key words: brook trout, wild trout, domesticated trout, interstrain hybrid trout, survival, growth, heterosis, hybrid vigor

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