Page 85 - Kutnar, Andreja, et al., eds., 2015. Proceedings of the 1st COST Action FP1307 International Conference - Life Cycle Assessment, EPDs, and modified wood. University of Primorska Press, Koper.
P. 85
ility
and
toxicity
of
heavy
metal(loid)s
arising
from
contaminated
wood
ash
application
to
a
pasture
grassland
soil
L.
Beesley1,
K.
Mitchell1,
L.
Mollon2,
G.J.
Norton2
1
The
James
Hutton
Institute,
Craigiebuckler,
Aberdeen,
AB15
8QH,
UK
2
University
of
Aberdeen,
Cruickshank
Building,
St.
Machar
Drive,
Aberdeen,
AB24
3UU,
UK.
Keywords:
Heavy
metal
toxicity,
bioavailability,
wood
ash,
arsenic,
chromium
Wood
modified
with
weatherproof
protectants,
paints,
and
preservatives
historically
contained
heavy
metals
and
organic
compounds.
After
combustion
of
these
woods
for
heat
and
power,
and
loss
of
more
volatile
organic
compounds
(VOC),
the
final
ash
is
concentrated
in
both
nutrients
from
the
biomass
and
heavy
metal(loid)s
arising
from
the
additive
treatments
(Balasoiu
et
al.
2001). One
way
to
dispose
of
wood
ash
without
dumping/landfilling
is
by
application
to
soil,
which
has
a
number
of
benefits
and
potential
concerns
associated.
For
example,
it
has
been
demonstrated
that
the
addition
of
wood
ash
to
soils
increases
pH
(Klemedtsson
et
al.
2010)
and
improves
crop
biomass
and
yields
(Bougnom
et
al.
2012).
However,
studies
that
have
used
wood
ash
generated
from
reclaimed
waste
(contaminated)
feedstocks
report
that
heavy
metals
derived
from
the
ash
are
bioavailable
and
potentially
phytotoxic,
negatively
impacting
crop
yields
(Lucchini
et
al.
2013)
and
introducing
potential
environmental
risk.
We
conducted
a
pot
experiment
to
investigate
the
fate
of
metal(loid)s
derived
from
contaminated
ash
(≤
10000
mg
kg-‐1
As,
Cr,
Cu
and
Zn;
Table
1)
added
to
an
upland
pasture
soil
(Aberdeenshire,
UK),
replicating
a
common
disposal
route
for
on-‐farm
generated
ash.
Metal(loid)
concentrations
were
measured
after
9
weeks
in
pore
water
and
ryegrass
grown
on
the
soil/manure-‐ash
mixtures
(0.1-‐3.0%
vol.
ash).
Toxicity
evaluation
was
performed
on
pore
waters
by
means
of
a
bacterial
luminescence
assay.
Table
1:
Metal(loid)
concentrations
(pseudo-‐total)
of
soil,
manure,
and
ash;
values
are
the
mean
of
replicates
(n=5)
±
s.e.m.
mg
kg-‐1
As
Cr
Cu
Zn
Soil
4.5
±
0.2
23.9
±
2.1
8.8
±
0.6
23.2
±
1.4
5.4
±
0.4
19.7
±
2.1
22.6
±
2.1
169.0
±
11.5
Manure
9259.4
±
649.3
9914.1
±
714.9
8793.4
±
632.0
4666.7
±
373.5
Ash
Both
pore
water
and
ryegrass
tissue
concentrations
of
As,
Cu,
and
Cr
were
elevated
by
ash
applications
compared
to
soils
receiving
no
ash.
Applying
ash
to
manure
amended
soil
buffered
some
phyto-‐toxicity
effects
associated
with
ash
application
to
non-‐manure
treated
soil,
by
regulating
pH
regardless
of
ash
application
volume.
This
was
evident
from
improved
ryegrass
biomass
and
bacterial
luminosity
concomitant
to
soil
without
ash
addition
(Fig.
1).
Pore
water
concentrations
of
As
and
Cu
significantly
correlated
with
ryegrass
uptake,
indicating
that
these
elements
were
the
most
bioavailable
of
those
investigated.
Cr
uptake
was
influenced
by
the
volume
of
ash
addition
but
ash
had
no
impact
on
either
pore
water
or
ryegrass
accumulation
of
Zn.
73
and
toxicity
of
heavy
metal(loid)s
arising
from
contaminated
wood
ash
application
to
a
pasture
grassland
soil
L.
Beesley1,
K.
Mitchell1,
L.
Mollon2,
G.J.
Norton2
1
The
James
Hutton
Institute,
Craigiebuckler,
Aberdeen,
AB15
8QH,
UK
2
University
of
Aberdeen,
Cruickshank
Building,
St.
Machar
Drive,
Aberdeen,
AB24
3UU,
UK.
Keywords:
Heavy
metal
toxicity,
bioavailability,
wood
ash,
arsenic,
chromium
Wood
modified
with
weatherproof
protectants,
paints,
and
preservatives
historically
contained
heavy
metals
and
organic
compounds.
After
combustion
of
these
woods
for
heat
and
power,
and
loss
of
more
volatile
organic
compounds
(VOC),
the
final
ash
is
concentrated
in
both
nutrients
from
the
biomass
and
heavy
metal(loid)s
arising
from
the
additive
treatments
(Balasoiu
et
al.
2001). One
way
to
dispose
of
wood
ash
without
dumping/landfilling
is
by
application
to
soil,
which
has
a
number
of
benefits
and
potential
concerns
associated.
For
example,
it
has
been
demonstrated
that
the
addition
of
wood
ash
to
soils
increases
pH
(Klemedtsson
et
al.
2010)
and
improves
crop
biomass
and
yields
(Bougnom
et
al.
2012).
However,
studies
that
have
used
wood
ash
generated
from
reclaimed
waste
(contaminated)
feedstocks
report
that
heavy
metals
derived
from
the
ash
are
bioavailable
and
potentially
phytotoxic,
negatively
impacting
crop
yields
(Lucchini
et
al.
2013)
and
introducing
potential
environmental
risk.
We
conducted
a
pot
experiment
to
investigate
the
fate
of
metal(loid)s
derived
from
contaminated
ash
(≤
10000
mg
kg-‐1
As,
Cr,
Cu
and
Zn;
Table
1)
added
to
an
upland
pasture
soil
(Aberdeenshire,
UK),
replicating
a
common
disposal
route
for
on-‐farm
generated
ash.
Metal(loid)
concentrations
were
measured
after
9
weeks
in
pore
water
and
ryegrass
grown
on
the
soil/manure-‐ash
mixtures
(0.1-‐3.0%
vol.
ash).
Toxicity
evaluation
was
performed
on
pore
waters
by
means
of
a
bacterial
luminescence
assay.
Table
1:
Metal(loid)
concentrations
(pseudo-‐total)
of
soil,
manure,
and
ash;
values
are
the
mean
of
replicates
(n=5)
±
s.e.m.
mg
kg-‐1
As
Cr
Cu
Zn
Soil
4.5
±
0.2
23.9
±
2.1
8.8
±
0.6
23.2
±
1.4
5.4
±
0.4
19.7
±
2.1
22.6
±
2.1
169.0
±
11.5
Manure
9259.4
±
649.3
9914.1
±
714.9
8793.4
±
632.0
4666.7
±
373.5
Ash
Both
pore
water
and
ryegrass
tissue
concentrations
of
As,
Cu,
and
Cr
were
elevated
by
ash
applications
compared
to
soils
receiving
no
ash.
Applying
ash
to
manure
amended
soil
buffered
some
phyto-‐toxicity
effects
associated
with
ash
application
to
non-‐manure
treated
soil,
by
regulating
pH
regardless
of
ash
application
volume.
This
was
evident
from
improved
ryegrass
biomass
and
bacterial
luminosity
concomitant
to
soil
without
ash
addition
(Fig.
1).
Pore
water
concentrations
of
As
and
Cu
significantly
correlated
with
ryegrass
uptake,
indicating
that
these
elements
were
the
most
bioavailable
of
those
investigated.
Cr
uptake
was
influenced
by
the
volume
of
ash
addition
but
ash
had
no
impact
on
either
pore
water
or
ryegrass
accumulation
of
Zn.
73
