Methylmercury (MeHg), dissolved organic carbon (DOC), and sulfate (SO(4)(=)) relationships were investigated in the mining-influenced St. Louis River watershed in northeast Minnesota. Fewer wetlands and higher SO(4)(=) in the mining region lead to generally lower availability and solubility of DOC in mining streams compared to non-mining streams. MeHg concentrations, however, are similarly low ...

Synthesis and reactivity of monomeric magnesium and zinc silyl compounds To(M)M-Si(SiHMe2)3 and To(M)M-Si(SiMe3)3 are described (To(M) = tris(4,4-dimethyl-2-oxazolinyl)phenylborate). The magnesium compounds react slowly with water and air, while the zinc compounds are inert. With CO2, To(M)Mg-Si(SiHMe2)3 provides To(M)MgO2CSi(SiHMe2)3 through CO2 insertion, whereas To(M)Zn-Si(SiHMe2)3 affords T...

A 1-D biogeochemical reactive transport model with a full set of equilibrium and kinetic biogeochemical reactions was developed to simulate the fate and transport of arsenic and mercury in subaqueous sediment caps. Model simulations (50 years) were performed for freshwater and estuarine scenarios with an anaerobic porewater and either a diffusion-only or a diffusion plus 0.1-m/year upward advec...

The atmosphere of Titan represents a bridge between the early solar nebula and atmospheres like ours. The low abundances of primordial noble gases in Titan's atmosphere relative to N2 suggest that the icy planetesimals that formed the satellite must have originated at temperatures higher than 75-100 K. Under these conditions, N2 would also be very poorly trapped and thus Titan's nitrogen, like ...

The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplan...

Concentration and composition of the fine particulate matter (PM) was measured using various online methods for 13 months in an urban, background area in Helsinki, Finland. Seasonal differences were found for ions and carbonaceous compounds. Biomass burning was found to increase inorganic ion and elemental carbon (EC) concentrations in winter, whereas organic carbon (OC) contribution was highes...

On a sequence of soils developed under similar vegetation, temperature and precipitation conditions, but with variations in mineralogical properties, we use organic carbon and C inventories to examine mineral protection of soil organic carbon. In these soils, C data indicates that the creation of slow-cycling carbon can be modeled as occurring through reaction of organic ligands with Al and Fe ...

The feasibility of using lignocellulosic biomass as a source for preparing carbon adsorbents has received rigorous attention over the last few decades. Many studies have discussed its great potential as a renewable feedstock for preparation of carbonaceous adsorbent materials. This review paper provides an overview of the different types of carbonization techniques that so far have been applied...

Rewetted, previously drained fens often remain sources rather than sinks for carbon and nutrients. To date, it is poorly understood which soil characteristics stimulate carbon and nutrient mobilization upon rewetting. Here, we assess the hypothesis that a large pool of iron in the soil negatively affects fen restoration success, as flooding-induced iron reduction (Fe3+ to Fe2+) causes a disprop...