Research Square (Research Square),
Journal Year:
2022,
Volume and Issue:
unknown
Published: Aug. 1, 2022
Abstract
Studies
of
fluid
flow
behavior
in
confined
aquifers
variable
thickness
presented
the
literature
assume
that
aquifer
varies
linearly
or
nonlinearly.
However,
natural
variations,
such
as
caused
by
complex
events,
cannot
be
accurately
predicted.
Therefore,
quantifying
variability
field
heterogeneous,
non-uniform,
may
done
from
a
stochastic
perspective.
In
this
study,
spatial
variations
hydraulic
conductivity
are
considered
stationary
random
process,
while
treated
nonstationary
process
with
homogeneous
(stationary)
increments.
General
expressions
for
covariance
functions
and
evolutionary
power
spectra
depth-averaged
head
integrated
specific
discharge
direction
x
1
derived
using
Fourier-Stieltjes
spectral
representation
approach
theorem.
Closed-form
solutions
used
to
analyze
effect
variation
on
discharge.
An
application
theory
developed
here
case
fields
exhibiting
power-law
semivariogram
is
given.
The
quantify
(uncertainty)
geologic
formations
under
uncertainty
should
provide
valuable
information
environmental
risk
assessment.
Journal of Soils and Sediments,
Journal Year:
2024,
Volume and Issue:
24(6), P. 2294 - 2308
Published: June 1, 2024
Abstract
Purpose
Particle
size
distribution
(PSD)
assessment,
which
affects
all
physical,
chemical,
biological,
mineralogical,
and
geological
properties
of
soil,
is
crucial
for
maintaining
soil
sustainability.
It
plays
a
vital
role
in
ensuring
appropriate
land
use,
fertilizer
management,
crop
selection,
conservation
practices,
especially
fragile
soils
such
as
those
the
North-Western
Himalayas.
Materials
methods
In
this
study,
performance
eleven
mathematical
three
Machine
Learning
(ML)
models
used
past
was
compared
to
investigate
PSD
modeling
different
from
Himalayan
region,
considering
that
an
model
must
fit
data.
Results
discussion
Our
study
focuses
on
significance
evaluating
goodness
particle
using
coefficient
determination
(R
2
adj
=
0.79
0.45),
Akaike
information
criterion
(AIC
67
184),
root
mean
square
error
(RMSE
0.01
0.09).
The
Fredlund,
Weibull,
Rosin
Rammler
exhibited
best
samples,
while
Gompertz,
S-Curve,
Van
Genutchen
poor.
Of
ML
tested,
Random
Forest
performed
0.99),
SVM
lowest
0.95).
Thus,
can
be
predicted
by
approaches,
model.
Conclusion
Fredlund
among
random
forest
machine
learning
models.
As
number
parameters
increased
better
accuracy.
Applied Geochemistry,
Journal Year:
2024,
Volume and Issue:
165, P. 105965 - 105965
Published: March 15, 2024
Cemented
paste
backfill
(CPB)
is
used
as
a
support
and
filler
material
in
underground
mines.
In
conditions,
before
mine
closure
flooding,
surface
groundwaters
with
variable
quality
are
contact
CPB
material,
which
may
result
the
leaching
of
harmful
substances
from
CPB.
this
study,
we
actual
water
gold
to
flush
laboratory
test
simulate
conditions
environmental
influence
on
more
realistically
than
before.
Different
materials
were
treated
columns
for
nine
months.
The
drained
filled
new
batches
four
times
during
experiment
intermittent
flushing
underground.
dissolved
elemental
content,
major
cations,
pH
oxidation-reduction
potential
(ORP)
waters
measured,
chemical
results
analysed
by
performing
geochemical
modelling
widely
code
PHREEQC.
X-ray
tomography
was
also
examine
internal
structure
specimens.
demonstrated
that
calcium
sulphate
present
parent
leached
into
water,
might
cause
deterioration
contrast,
concentrations
As,
Sb
Ni
decreased
when
it
materials.
However,
arsenic
started
be
re-released
at
end
nine-month
experimental
period.
suggests
removal
metals/metalloids
driven
complexation
reactions
originally
and/or
freshly
precipitated
metal
(hydr)oxide
minerals.
A
longer
modified
testing
period
needed
thoroughly
under
these
adsorbed
elements
start
release
over
time.
Applied Geochemistry,
Journal Year:
2021,
Volume and Issue:
130, P. 104984 - 104984
Published: May 12, 2021
The
fundamental
understanding
of
hydrogeochemical
processes
leading
to
toxic
drainage
in
mining
environments
is
utmost
importance
predict
the
impact
activities
waste
facilities
and
design
effective
measures
for
mitigation
environmental
risk.
This
study
investigates
weathering
behavior
different
types
mine
rocks,
with
considerably
mineralogical
textural
properties,
by
performing
long-term
(>3
years)
pilot-scale
lysimeter
experiments
combined
multiphase
multicomponent
reactive
transport
modeling.
were
carried
out
a
series
five
setups,
packed
unsaturated
rocks
collected
from
Kevitsa
Hitura
sites
Finland,
under
influence
outdoor
atmospheric
conditions.
We
focus
on
temporal
dynamics
rock
effluents'
chemistry
showing
remarkably
compositions
experiments.
low-sulfide
containing
pyroxene
serpentinite
lead
alkaline
drainage,
characterized
higher
pH
(up
9.5)
lower
dissolved
constituents
(e.g.,
up
420
mg/L
SO4,
89
μg/L
Ni).
In
contrast,
effluents
mica
schist
which
have
relatively
sulfide
abundance,
show
characteristics
acidic
(~4.3)
orders
magnitude
aqueous
concentrations
3100
130
results
also
that
presence
fraction
finer
particles
leads
faster
dissolution
rate
thus
concentrations.
experimental
quantitatively
interpreted
modeling,
allowed
capturing
complex
dynamic
trends
concentration
levels
observed
lysimeters.
Advances in Water Resources,
Journal Year:
2022,
Volume and Issue:
169, P. 104303 - 104303
Published: Aug. 30, 2022
The
exchange
of
gas
components
across
the
subsurface/atmosphere
interface
influences
multiphase
flow
and
reactive
transport
in
subsurface
is
crucial
for
many
biogeochemical
processes,
emission
greenhouse
gases,
fate
volatile
contaminants.
In
this
study,
we
present
a
modeling
approach
to
simulate
non-isothermal
multicomponent
coupled
compartments.
model
based
on
porous
medium/free
domain
which
Navier-Stokes
equation
used
describe
single-phase
(gaseous)
free-flow
subdomain
Darcy's
law
applied
two-phase
medium
(i.e.,
two-domain
approach).
implementation
performed
by
coupling
COMSOL
Multiphysics
PhreeqcRM,
enables
investigation
interplay
between
multi-physical
processes
flow,
mass
heat
transport)
compartments
geochemical
reactions
medium.
We
first
set
benchmark
examples
key
features
proposed
are
tested
against
other
numerical
simulators
an
analytical
solution.
Successively,
take
advantage
unique
capabilities
explore
conservative
domain.
results
show
that
control
location
zones
extent
mineral
dissolution)
changing
spatiotemporal
distribution
fluid
phases
enhancing
interphase
transfer
such
as
oxygen
carbon
dioxide.
Geochimica et Cosmochimica Acta,
Journal Year:
2021,
Volume and Issue:
318, P. 230 - 246
Published: Dec. 6, 2021
Coulombic
interactions
between
charged
species
in
pore
water
and
at
surface/solution
interfaces
are
of
pivotal
importance
for
multicomponent
reactive
transport
porous
media.
In
this
study,
we
investigate
the
impact
domain
dimensionality
on
electrostatically
coupled
dispersion
surface-solution
reactions
during
acidic
plumes
major
ions
Column
quasi
two-dimensional
flow-through
experiments
were
performed,
with
identical
silica
media
under
same
advection-dominated
conditions.
Equal
mass
fluxes
different
electrolyte
solutions
(i.e.,
HCl
-
pH
∼
2.8,
NaBr
100
mM,
2.8
plus
mM)
continuously
injected
1-D
2-D
breakthrough
curves
measured
outlet
domains.
The
presence
pronounced
ionic
strength
gradients
transverse
direction
setup
caused
distinct
retardation
behaviors
protons
which
not
observed
one-dimensional
column
experiments.
Furthermore,
cases
salt
electrolytes
injection,
considerably
enhanced
release
H+
(>61%)
from
quartz
surface
was
multidimensional
system
compared
to
setup.
Reactive
modeling
performed
reproduce
experimental
outcomes
analyse
coupling
processes,
based
Nernst-Planck
formulation
diffusive/dispersive
complexation
solid-solution
interface.
Electrostatic
Na+,
Br−,
H+,
deprotonation
upon
formation
sodium
outer-sphere
complexes,
primary
controllers
spatial
temporal
features
displayed
by
measurements.
simulations
allowed
us
interpret
observations,
visualize
distribution
spatio-temporal
evolution
dissolved
solid
species,
identify
a
spatially
heterogeneous
zonation
behavior
fringe
core
setup,
quantify
components
Nerst-Planck
solutes.
This
study
demonstrates
that
directly
affects
electrostatic
aqueous
non-trivial
effects
result
significantly
systems.
Journal of Geochemical Exploration,
Journal Year:
2022,
Volume and Issue:
237, P. 106996 - 106996
Published: April 5, 2022
Humidity
cell
test
represents
one
of
the
most
popular
geochemical
characterization
methods
for
predicting
reactivity
and
estimating
leachate
quality
mining
waste
materials.
Yet,
interpretation
such
laboratory
results
can
vary
widely,
its
validity
applicability
be
impaired
by
poor
experimental
details,
sample
representation,
inability
to
correctly
identify
key
contributions
relevant
processes.
In
this
study,
we
investigate
leaching
behavior
mine
rocks,
collected
from
Särkiniemi
site
in
Finland,
means
humidity
tests.
The
experiments
were
performed
according
ASTM
standard
D5744–18
utilizing
two
distinct
cells,
packed
with
same
rock,
considerably
different
dimensions
shapes.
show
higher
chemical
weathering
rates
rocks
mass
loadings
elements
(approximately
two-
threefold)
long/narrow
shaped
setup
compared
short/broad
cell.
observed
concentrations
also
suggest
possibility
potential
influences
microscale
heterogeneity,
despite
attempts
homogenize
rock
samples
crushing
mixing
prior
packing.
quantitatively
interpreted
process-based
multiphase
multicomponent
reactive
transport
modeling,
which
allowed
detailed
examination
complex
interplay
between
reactions
physical
processes,
helped
distinguishing
dominant
mechanisms,
facilitated
identification
controlling
factors
leading
fundamental
challenges
associated
analysis
results.
While
could
reproduced
fitting
conceptual
models
or
adjusting
model
parameters,
suggests
that
simulation
outcomes
cannot
fundamentally
treated
as
predictive
without
proper
knowledge
dynamics
water
flow
solute/gaseous
during
these
