3 research outputs found
Assessing dissolved methane patterns in central New York groundwater
Study region: Groundwater in Chenango County (central New York State, USA), which is underlain by Devonian sedimentary bedrock. This region has conventional natural gas wells and is under consideration for future shale gas development using high-volume hydraulic fracturing.
Study focus: The study examines current patterns of dissolved methane in groundwater, based on 113 samples from homeowner wells in the spring of 2012. Samples were analyzed for methane and other water quality parameters, and each well characterized by its landscape position and geology. Statistical testing and regression modeling was used to identify the primary environmental drivers of observed methane patterns.
New hydrological insights for this region: There was no significant difference between methane concentrations in valleys versus upslope locations, in water wells less than or greater than 1Ā km from a conventional gas well, and across different geohydrologic units. Methane concentrations were significantly higher in groundwater dominated by sodium chloride or sodium bicarbonate compared with groundwater dominated by calcium bicarbonate, indicating bedrock interactions and lengthy residence times as controls. A multivariate regression model of dissolved methane using only three variables (sodium, hardness, and barium) explained 77% of methane variability, further emphasizing the dominance of geochemistry and hydrogeology as controls on baseline methane patterns
Oxygen-Content-Controllable Graphene Oxide from Electron-Beam-Irradiated Graphite: Synthesis, Characterization, and Removal of Aqueous Lead [Pb(II)]
A high-energy electron beam was applied
to irradiate graphite for the preparation of graphene oxide (GO) with
a controllable oxygen content. The obtained GO sheets were analyzed
with various characterization tools. The results revealed that the
oxygen-containing groups of GO increased with increasing irradiation
dosages. Hence, oxygen-content-controllable synthesis of GO can be
realized by changing the irradiation dosages. The GO sheets with different
irradiation dosages were then used to adsorb aqueous PbĀ(II). The effects
of contact time, pH, initial lead ion concentration, and ionic strength
on PbĀ(II) sorption onto different GO sheets were examined. The sorption
process was found to be very fast (completed within 20 min) at pH
5.0. Except ionic strength, which showed no/little effect on lead
sorption, the other factors affected the sorption of aqueous PbĀ(II)
onto GO. The maximum PbĀ(II) sorption capacities of GO increased with
irradiation dosages, confirming that electron-beam irradiation was
an effective way to increase the oxygen content of GO. These results
suggested that irradiated GO with a controllable oxygen content is
a promising nanomaterial for environmental cleanup, particularly for
the treatment of cationic metal ions, such as PbĀ(II)