2 research outputs found
A MIL-101 Composite Doped with Porous Carbon from Tobacco Stem for Enhanced Acetone Uptake at Normal Temperature
A high-efficiency adsorbent for acetone
under normal temperature
was prepared with metal–organic framework MIL-101 doped with
porous carbon from tobacco stem (MIL-101/TC) by a solvothermal synthesis
method. These synthesized composites were characterized and then investigated
for acetone adsorption at 288 and 298 K up to 20 kPa. The isosteric
heat of adsorption was estimated from adsorption isotherms of acetone
vapor. Temperature programmed desorption (TPD) was employed to calculate
the activation energies of acetone desorption on MIL-101/TC and MIL-101.
Results of characterization showed that MIL-101/TC possessed crystal
structure and morphology similar to those of MIL-101. Despite the
smaller BET surface area, MIL-101/TC-40 and MIL-101/TC-30 composites
had much higher acetone uptakes of 1137 and 1123 mg/g at 18.9 and
18.1 kPa in 288 K, respectively, which increased by 19.8% and 18.3%
compared with those of MIL-101 composites. The increase in acetone
uptakes was attributed to the associative effect of the enhancement
of the surface dispersive forces and the activation of the unsaturated
metal sites by TC loading. The isosteric heat of acetone adsorption
on MIL-101/TC was much higher than that on MIL-101, and the maximum
isosteric adsorption heat on MIL-101/TC-40 was 52 kJ/mol. The activation
energy of desorption obtained through TPD ranged from 24.5 to 48.5
kJ/mol. The acetone adsorption isotherms of the composites could be
fitted favorably by the L-F and DSLF equations
Fates of Terrigenous Dissolved Organic Carbon in the Gulf of Maine
A significant amount of organic carbon is transported
in dissolved
form from soils to coastal oceans via inland water systems, bridging
land and ocean carbon reservoirs. However, it has been discovered
that the presence of terrigenous dissolved organic carbon (tDOC) in
oceans is relatively limited. Therefore, understanding the fates of
tDOC in coastal oceans is essential to account for carbon sequestration
through land ecosystems and ensure accurate regional carbon budgeting.
In this study, we developed a state-of-the-art modeling approach by
coupling a land-to-ocean tDOC flux simulation model and a coastal
tDOC tracking model to determine the potential fates of tDOC exported
from three primary drainage basins in the Gulf of Maine (GoM). According
to our findings, over half a year in the GoM, 56.4% of tDOC was mineralized.
Biomineralization was responsible for 90% of that amount, with the
remainder attributed to photomineralization. Additionally, 37% of
the tDOC remained suspended in the GoM, and 6.6% was buried in the
marine sediment