Water Air Soil Pollut (2012) 223:1237–1247
DOI
10.1007/s11270-011-0940-4 V. Feigl (*) : K. Gruiz Budapest University of Technology and Economics, 1111 Szent Gellért tér 4, Budapest, Hungary
e-mail: vfeigl@mail.bme.hu A. Anton : N. Uzigner Research Institute for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, 1022 Herman Ottó u. 15, Budapest, Hungary
waste product, since it has many potential reuse applications, which could help reduce the amount of storage needed for this by-product. Potential construction
and chemical applications include uses in
building construction, catalyst support, ceramics, plastics, and coatings or pigments. Metallurgical applications include uses in recovery of major and minor metals, steel making, and as a slag additive.
Environmental and
agronomic applications
include
uses in water and waste
treatment, gas scrubbing, and
as soil amendment (Klauber
et al. 2009). For
example, the application of
red mud to soil can
potentially reduce the
eutrophication of rivers and
waterways by retaining
nutrients, especially
phosphate,
on infertile sandy soils.
Summers et al. (1993)
treated sandy soil with 80
t/ha of red mud neutralized
with waste gypsum and
reduced phosphorous losses
by 70%. Ward and Summers
(1993) concluded that
neutralization with gypsum is
unnecessary for application
to pasture land at less than
100 t/ha. Summers
et al. (1996) recommended
an optimal red mud
application rate (without
gypsum) of 10–20 t/ha to
reduce phosphorus leaching
and noted that the
improved nutrient retention
continues for at least
5 years after fertilizer
application.
Red mud may also be
applied to soil to immobilize
metals by chemical
stabilization. Phillips (1998)
found that red mud mixed
into sand has a greater
ability to sorb Cu2+, Pb2+,
and Zn2+ ions than do
zeolite and calcium
phosphate. Müller and
Pluquet
(1998) showed that red mud
can reduce the soluble
amount of Zn and Cd by
50% and reduce the metals
uptake of plants by 20–50%.
However, in a field trial,
they observed lower
immobilizing efficacy on the
metal concentrations in
plants and soil extracts. They
concluded that the red mud
used in the experiments
contained excessive
concentrations of Cr and Al,
which made it unsuitable for
soil remediation. In
contrast, Gray et al. (2006)
used red mud with a Cr
concentration of 1,377 mg/kg for stabilization of
metals in soil and noted that Cr was not soluble or available for plants when mixed into soil. Although this issue may be important for Cr-containing red muds, there are a number of red muds that do not contain chromium or other toxic metals.
Lombi et al. (2002a, b) compared the performance of red mud (from Mosonmagyaróvár, Hungary), lime,
and beringite as stabilizers for Cd-, Pb-, Zn-, Cu-, and
Ni-contaminated soil and found that all were similarly effective in reducing the metal concentrations in the soil pore water. In fact, only 2% (w/w) of red mud was needed to be as effective as 5% (w/w) beringite; also, the microbial biomass of the soil significantly increased
in the presence of red mud. The red mud
shifted metals in soil from the exchangeable (ionic) fraction to the Fe oxide
fraction, which may result in
a
more durable decrease in
metal mobility than liming.
Brown et al. (2005) showed
that red mud (from
Mosonmagyaróvár, Hungary)
can reduce ammonium
nitrate-extractable,
water-extractable, and
bioavailable
Zn and Cd, but does not
affect Pb. In a field
experiment using 5% red
mud, Gray et al. (2006)
found effective (70–96%)
reductions of metals such as
Zn, Cd, and Ni in pore water
and soil extracts. No
significant Pb reductions
were observed in the first
5 months, but by the 25th
month, Pb was immobilized.
Friesl et al. (2004, 2006,
2009) conducted several
pot and field experiments
with red mud from
Mosonmagyaróvár. Their
2004 results were similar
to those of Lombi et al.
(2002a), but they also found
that red mud applied at 5%
(w/w) increased the
ammonium
nitrate-extractable As, Cu, Cr,
and V in
soil. In their 2006 field
experiment, they showed that
red mud applied
approximately 15 cm below
the soil
surface can reduce the
ammonium
nitrate-extractable
Cd, Zn, and Pb up to 99%
but that deeper application
may be needed to reduce
plant metal uptake. Finally,
in 2009, Friesl et al.
concluded that red mud and
gravel sludge (a fine-grained
waste product of the
gravel industry consisting of
40–65% SiO2, 10–
14% Al2O3, 3–7% Fe2O3,
5–12% CaO, and 4–6%
MgO at pH 8.2), in
combination with a
metalexcluding
barley cultivar (Hordeum
distichon ssp. L.),
performed most effectively
as a stabilizer for the
metal-contaminated soil at an
experimental site in
Arnoldstein, Austria.
The application of red mud on mine waste and
metal-contaminated soils has been integrated into a complex risk management activity and is one of the risk reduction measures that will be implemented in a large catchment. The complex remediation concept
involves the removal of the point sources and treating the diffuse pollution with a combination of chemical stabilization and phytostabilization (Gruiz et al.
2009a). To find the suitable red mud concentration
and plant combination, a number of researchers have conducted laboratory soil microcosm experiments (Feigl et al. 2007, 2009; Anton and Barna 2008). 1238 Water Air Soil Pollut (2012) 223:1237–1247
The experiment described in this paper introduces
the remediation of metal-contaminated soils using red
mud for chemical
stabilization/immobilization
followed
by phytostabilization. The
2-year study focuses
on long-term results in
laboratory soil microcosms.
2 Materials and Methods
2.1 Materials
During the 2-year study, we
evaluated the stabilization
performance of red mud
from Almásfüzit?, Hungary
on toxic, metal-contaminated
soils and mine wastes
from the former Pb and Zn
sulfide ore mine in
Gy?ngy?soroszi, Hungary
(Gruiz et al. 2009a). The
Almásfüzit? red mud has a
relatively low pH (9.0)
compared to most red muds,
which generally have pH
of approximately 11.3 (Gr?fe
et al. 2009). The
Almásfüzit? red mud also
has low toxic metal content
(below the Hungarian quality
criteria for sewage
sludge application on soil, as
stipulated in Government
Decree No. 50/2001)
compared to the highly
alkaline red muds with high
Cr content used in some
of the studies discussed in
Section 1. Characteristics
of the red mud, soil, and
mine waste are presented in
Table 1.
The soil originated from an
agricultural area
downstream of the former
mine and is heavily
contaminated with toxic
metals, especially mobile
Cd and Zn. Contamination is
the result of severe
flooding of the Toka creek,
which transports the
metals from the abandoned
mine. The mine waste
originated from waste rock
heaps near the main
entrance of the mine. These
partly uncovered waste
deposits have been exposed
to intensive weathering
for more than 40 years,
resulting in acidification,
leaching, and oxidation.
2.2 Soil Treatment
Our test samples consisted of
three replicates placed
in 2 kg plastic plant pots. Test
samples included a
control (with no amendment) mine waste and contaminated
soil, and each mixed with 2% and 5% (w/w)
red mud. All were incubated at 25°C, mixed, and watered to 60% of their water-holding capacity every second month and after sampling. The soil was sampled and analyzed for complex chemical and biological processes. Short-term changes were monitored
by sampling at 0, 10, 20, and 45 days after amendment, and long-term effects were monitored after 9 months and 2 years.
2.3 Integrated Monitoring We monitored the decreased mobility, solubility,
and bioavailability of toxic metals in the amended
soil samples using a methodology that integrates physical–chemical analysis and ecotoxicity testing (Gruiz et al. 2005, 2009b) (Fig. 1). We evaluated the results of chemical analysis
and toxicity measurements
to determine whether the
addition of red mud
could reduce the mobility,
bioavailability, and risks
posed by pollutants in the soil
and, hence, whether
red mud could be used as a
stabilizing agent for the
Gy?ngy?soroszi mine waste.
Gruiz et al. (2005)
postulated that the actual
risks posed by a mixture of
various metals and their
species can be better
characterized by measuring
adverse biological and
toxicological effects. Plant
toxicity and bioaccumulation
measurements were used to
characterize the
dynamic interactions
between the red mud, the
treated medium, and the
living organisms and to
provide direct information on
the actual adverse
effects of the pollutants
before and after remediation.
2.3.1 Sample Preparation
To prepare soil samples for
the integrated monitoring,
we air-dried, ground, and
sieved (2-mm sieve) the soil
samples according to
Hungarian Standard 21470-
50:2006.
2.3.2 Chemical Analysis
To predict mobile metals
concentrations, we used
Hungarian Standard HS
21978-9:1998 and analyzed
both distilled water extract
(pH 7.0; 1:10 soil
extractant ratio; agitation for
4 h at 25°C) and
ammonium acetate extract
(pH 4.5; 1:10 soil extractant
ratio; agitation for 4 h at
25°C). We characterized
As mobility using its
concentration in the sodium
hydroxide and sodium
carbonate extract (1:0.56
mol;
pH 7.5; 1:20 soil extractant
ratio; 1 h at 90°C) (HS
21470-50:2006). We
measured the total metals
content
after aqua regia digestion (3:1
hydrochloric acid–
nitric acid ratio; 1:4 soil
extractant ratio; 2 h at 25°C;
Water Air Soil Pollut (2012)
223:1237–1247 1239 Table 1 Characteristics of red mud from Almásfüzit?, contaminated agricultural soil, and mine waste Parameter HQC for
soila
HQC for
sludgeb
Red mud Agricultural soil Mine waste
Aqua regia
extract
Ammonium acetate extract
Water
extract
Aqua regia
extract
Ammonium acetate extract
Water
extract
Aqua regia
extract
Ammonium acetate extract
Water
extract
Al ––125,000 197 60.9 38,780 3.87 0.531 27,924 0.547
As 15 75 47.4
Ba 250 – 61.7
5.12 0.599 393 2.23 0.367
Cd 1 10 0.770
8.85 1.37 0.019 21.8 2.43
0.014
Co 30 50 23.6
22.2 0.026 0.013 11.9 0.127
0.019
Cr 75 1,000 193
28.2
Cu 75 1,000 48.9
163 1.20 0.537 353 0.545
0.122
Hg 0.5 10
0.963
Mo 7 20
0.675
0.095
Ni 40 200 112
17.1 0.419
0.009
Pb 100 750 63.0
440 1.01
Se 1 100
1.90
Sn 30 – 14.2
Zn 200 2,500 77.5
1,601 214 2.52 4,488 207
1.28
pH 7.0 9.0 4.7 7.4 5.9 7.3
All units in milligrams per
kilogram, except pH
a Hungarian Quality Criteria
for soil based on
KvVM-EüM-FVM Joint
Decree No. 6/2009
b Hungarian Quality Criteria
for sludge from waste water
treatment for agricultural
applications based on
Government Decree No.
50/2001
1240 Water Air Soil Pollut
(2012) 223:1237–1247
microwave digestion) (HS
21470-50:2006). Finally,
we determined the metal
contents of all of the extracts
with inductively coupled
plasma atomic emission
spectroscopy (ICP-AES)
using an Ultima 2 (HORIBA
Jobin Yvon, France) (HS
21470-50:2006).
We measured the average
yearly leaching of metals
from the amended soil in a
mini-lysimeter developed
by RISSAC (2006). To determine the leachable metals
at the end of the 2-year experiment, we used a Wittetype
porcelain plate covered with silk bunting placed
on the bottom of a Schachtschabel-type glass column
(31 mm inner diameter). We ground and sieved 200 g (1 mm sieve) of soil from the original test sample. We simulated the composition of rain using a 0.16 mM
CaCl2 solution, wetted the columns with the CaCl2 solution to their maximum water-holding capacity,
and equilibrated them for 48 h. We modeled 1 year of rainfall by adding 12 fractions of 50-ml aliquots of the CaCl2 solution over a 3-week period. For the
Gy?ngy?soroszi area, we estimated the yearly amount of rainfall to be 756 mm/year between 1982 and 2002 (data from Hungarian National Meteorological Service).
We determined the metals
content of the leachates using
ICP-AES (HS
21470-50:2006).
2.3.3 Biological and
Ecotoxicological
Measurements
We selected the Sinapis alba
(white mustard) for
toxicity testing. Using a root
and shoot growth
inhibition test, developed by
Gruiz et al. (2001) that
modified Hungarian
Standard 21976-17:1993
(Seedling
plant test for waste) to direct
contact with soil,
and an innovative 5-day
bioaccumulation test we
developed for this study, we
obtained direct information
on the suitability of the
chemical stabilizer for
plant growth and uptake.
Field experiments by Feigl
et al. (2010) using the
bioaccumulation tests show
good agreement with field
data for predicting the
efficiency of the stabilizing
amendments.
We placed 20 S. alba seeds
on 5 g of soil wetted to
saturation (two replicates)
and incubated them at 20°
C for 3 days in darkness. We
then measured the length
of the roots and shoots. For
the bioaccumulation test,
we placed 40 S. alba seeds
on 5 g of saturated soil
(two replicates) and
incubated them at 20°C for 5
days
in darkness. At day 3, we
added water to compensate
for water losses. After 5 days,
we separated the
shoots, washed them with
water, and dried them. We
measured the metal contents
of the mixed plant
material using ICP-AES (HS
21470-50:2006) after
digestion with 10 ml nitric
acid and 4 ml hydrogen
peroxide for 3 h at 105°C.
2.3.4 Statistical Analysis
To determine if the various
treatments significantly
reduced metal mobility, we
performed a variance
analysis using StatSoft?
Statistica 9.0. We established
the level of significance to be p<0.05. We used Fisher’s least significant difference test for comparison
of the various treatments.
3 Results and Discussion 3.1 Chemical Extractions Table 2 shows the effect of red mud on the pH and the ammonium acetate- and water-extractable metal contents
of the treated contaminated soil and mine waste
after 2 years of monitoring. An addition of 2% red mud increased the neutral pH of the soil and mine waste by Fig. 1 Integrated monitoring methodology
Water Air Soil Pollut (2012) 223:1237–1247 1241
only pH 0.1–0.2; a 5% addition increased pH by 0.3. This is a much smaller increase than that experienced by researchers who applied more alkaline red muds (pH 10.2). Lombi et al. (2002a), Brown et al. (2005), and Gray et al. (2006) saw increases of pH 0.7–2.3
after the addition of 2% red
mud. Friesl et al. (2004),
however, observed a pH
increase of only 0.4 when
adding 5% red mud to
neutral soils (pH 7.4–7.6).
The mobility of all metals
(Cd, Zn, Pb, and As)
decreased after red mud
addition. The best results
were gained for Cd and Zn:
A 5% red mud addition
decreased the
water-extractable amount of
Cd and Zn
by 57% and 87%,
respectively, in the
agricultural soil
and by 73% and 79%,
respectively, in the mine
waste.
The addition of 2% red mud
was less effective:
Decreases of 32% and 78%,
respectively, were
observed in the soil’s
water-extractable Cd and Zn
content and 34% and 30%,
respectively, in the acidic
mine waste.
Similar efficiencies were
observed by Gray et al.
(2006) in a 2-year field
experiment with the
ammonium
nitrate-extractable metal
fractions, by Lombi et
al. (2002a) in a 1-year pot
experiment in the
exchangeable fraction, and
by Friesl et al. (2004) in
a 2-week laboratory
experiment with the
ammonium
nitrate-extractable metal
fractions. Friesl et al. (2004)
found that the ability of red
mud to reduce metal
mobility largely depended on
soil type and was up to
91% for Cd and 94% for Zn.
After comparing the effects
of red mud to those of
beringite and lime, Lombi et
al. (2002a) suggested
that the dominant
mechanism involved in the
immobilization
of metals by red mud is the
increase in pH.
However, they also
suggested that the
immobilization
could be due to specific
chemisorptions and metal
diffusion into the lattice of Fe and Al oxides, which results in more durable reduction in metal mobility than liming. Our study indicates the latter, as the soil pH in our study did not significantly increase due to the addition of pH 9.0 red mud.
Additions of 5% red mud were more efficacious in immobilizing ammonium acetate extractables in the Table 2 Characteristics of red mud-treated agricultural soil and mine waste Parameter Agricultural soild Mine wasted Percentage decrease in metal content due to
red mud addition compared to untreatede
Soil only + 2%
red mud
+ 5%
red mud
Mine waste
only
+ 2%
red mud
+ 5%
red mud Soil+2%
red mud
Waste+2%
red mud
Soil+5%
red mud
Waste+5%
red mud
pH 6.9 7 7.2 7 7.2 7.3
Cda 1.31a 1.27a 1.10b 2.62a
2.12b 1.54c 1 18 11 38
Cdb 0.017a 0.011ab 0.007b
0.022a 0.015a 0.005a 32 34
57 73
Zna 200a 153b 110c 239a
151b 90.7b 22 35 42 60
Znb 1.95a 0.415b 0.241b
1.39a 0.946ab 0.266b 78 30
87 79
Pba 0.981a 0.819b 0.536c
7.51a 6.15a 3.10a 15 16 43
56
Pbb <0.060a <0.060a
<0.060a <0.060a <0.060a
<0.060a
Asa 0.203a 0.103b <0.080b
<0.080a <0.080a <0.080a 49
Asb <0.080a <0.080a
<0.080a <0.080a <0.080a
<0.080a
Asc 44.2a 27.9a 21.8b 108a
56.7b 30.1b 37 48 51 72
Same letter per column
indicates no significant
difference from their
non-amended control (level
of significance: p<0.05).
Decrease
calculated by taking the red
mud metal content into
account
Average of five samplings
(10 and 20 days, 2 and 6
months, and 2 years after the
treatment). No significant
change was observed in
metal concentrations over
2-year period
a Ammonium acetate
extraction
b Distilled water extraction
c Alkaline extraction.
Performed only at the 5th
sampling, 2 years after
treatment
d Milligrams per kilogram,
except for pH
e Percent decrease
1242 Water Air Soil Pollut
(2012) 223:1237–1247
mine waste than in the
agricultural soil. The
ammonium
acetate-extractable Cd, Zn, and Pb content decreased by 38%, 60%, and 56%, respectively, in
the mine waste but decreased only 11%, 42%, and 43%, respectively, in the soil. In spite of the greater immobilization in mine wastes, statistical evaluation of the results showed a lower significance for the
waste than the soil, perhaps because of the heterogeneity of the waste and the fact that the original mine
waste contained larger amounts of ammonium acetate-extractable metals, especially Cd and Pb. Lombi et al. (2002a) measured the extractable metal
content in red mud-treated soil after acidification with
a mixture of sodium nitrate and nitric acid for 7 days. Their results showed that the extractable amounts of metals in red mud-treated soil were always smaller
than extracted from the control samples or the
limeand
the beringite-treated soils.
The soil and mine waste
applied in our experiment
contained As. The
immobilization of this
element by
red mud has not been
thoroughly investigated.
Friesl
et al. (2004) found that the
ammonium nitrateextractable
As concentrations increased
upon red
mud addition due to pH
increases. Our results show
that red mud is able to reduce
the mobility of As: A
59% decrease in As was
observed in the ammonium
acetate extract of the soil, and
decreases of 51% and
72% were observed in the
alkaline extracts of soil and
mine waste, respectively.
Usually As mobility is
controlled by adsorption/
desorption processes and
co-precipitation reactions
with metal oxides; therefore,
the most extensively
studied amendments for As
immobilization are
elemental iron and Fe(II) or
Fe(III) oxides and, to a
lesser extent, Al (aluminum
hydroxide) and Mn
(hydrous manganese oxides
or birnessite) (Kumpiene
et al. 2008). Because red
mud contains 41% iron
oxides (such as hematite,
goethite, and magnetite) and
16% aluminum oxides (such
as boehmite, gibbsite,
and diaspore) (Gr?fe et al.
2009), it is efficient in As
immobilization.
Other authors found
increasing Cu mobility
(Lombi et al. 2002a; Friesl et
al. 2004) and Cr
mobility (Friesl et al. 2004;
Gray et al. 2006) in the
red mud-treated soils. The
increase in Cu mobility is a
result of the increase in
dissolved organic matter,
since Cu tends to strongly
absorb to organic matter,
while Cr either originates
from the red mud itself (our
red mud contained 193
mg/kg Cr) or is mobilized
due
to the pH increase. In our study, Cu was immobilized by the addition of red mud. The total amount (in aqua regia extract) of Cr in soils increased from 29.9 to 35.4 mg/kg (2% red mud) and from 29.9 to 45.4 mg/kg (5% red mud). Mine waste samples showed Cr increases from 55.4 to 58.0 mg/kg (2% red mud)
and from 55.4 to 72.2 mg/kg (5% red mud). However, short-term measurements (10–45 days) showed a small increase in Cr in the ammonium acetate extraction, from <0.02 to 0.03?0.07 mg/kg (5% red mud) in the agricultural soil (no increase was observed in the treated mine waste). The Cr mobilization had ceased by the next sampling
event at 9 months (data not shown).
3.2 Mini-lysimeter Study
In the mini-lysimeter experiment, an addition of 2%
red mud decreased the Cd and Zn concentrations in
the soil leachate to
approximately two third of
the
level of the leachate from the
untreated soil; addition
of 5% red mud decreased the
Cd and Zn to
approximately one third of
the untreated soil sample
(Figs. 2 and 3). Gruiz et al.
(2006) determined the
Maximum Effect Based
Quality Criteria (EBQCmax)
for surface water in the
metal-contaminated area of
the Toka valley near
Gy?ngy?soroszi, Hungary.
These
criteria are the maximum
metals concentrations that
should not be exceeded in
seepage from remediated
areas and are: As, 10 μg/l;
Cd, 1 μg/l; Zn, 100 μg/l;
and Pb, 10 μg/l. Figures 2
and 3 show that both 2%
Fig. 2 Cadmium
concentrations in the leachate
from the minilysimeters;
circle untreated soil, square
2% red mud treatment,
triangle 5% red mud
treatment
Water Air Soil Pollut (2012)
223:1237–1247 1243
and 5% red mud additions
decrease Zn levels to
below the EBQCmax target
value, while reduction of
Cd to the target level occurs
only with 5% red mud
addition.
The As concentrations in
leachate from untreated
soils (4–8 μg/l) were below
the EBQCmax, and there
was no significant change in
these values after the
addition of red mud. Pb
concentrations were below
the detection limit (1.5 μg/l).
Despite the increase of
Cr in the ammonium acetate
extract in the short term,
Cr measurements remained
below the detection limit
(0.5 μg/l) in the soil
leachate. In the first leachate
sample, Cu concentrations
increased by 30% with the
addition of 2% red mud and
by 70% with the addition
of 5% red mud (as compared
to the leachate from
non-treated soil), but by the
fifth leachate sample, the
Cu concentrations had decreased to less than that of the non-treated soil (data not shown). The results from the mini-lysimeter study indicate that red mud treatment decreases the amounts of metals leached to the groundwater.
3.3 Plant Ecotoxicity Test The toxicity of the soil and mine waste did not change significantly due to red mud addition (Fig. 4), indicating that the addition of red mud to the soil
and mine waste as chemical stabilizer did not increase the toxicity of the soil ecosystem. The addition of 5%
red mud to the agricultural soil increased the root and shoot length of S. alba test plants by 40% and 46%, respectively, as compared to non-treated soil. This can
be attributed to a reduction in plant-available toxic metals, which inhibited plant growth. The reduction
of plant toxicity is important for revegetation following
chemical stabilization.
Combined chemical
stabilization
and phytostabilization
technology aims to
produce a healthy vegetative
cover that decreases
runoff, normalizes the soil
water balance, reduces
erosion of the formerly bare
areas, and improves
esthetics.
3.4 Plant Bioaccumulation
To predict the proportions of
metals available for plant
uptake, we applied a 5-day
bioaccumulation test using
S. alba; the test was
developed to provide a rapid
estimation of plant metals
uptake. The metals uptake
of test plants is shown in Figs.
5 and 6. For
Fig. 3 Zinc concentrations in
the leachate from the
minilysimeters;
circle untreated soil, square
2% red mud treatment,
triangle 5% red mud
treatment
Fig. 4 Effect of red mud
(RM)-treated soil (S) and
mine waste
(W) on S. alba plant root and
shoot growth
Zn
Cd
0.0
0.2
0.4
0.6
0.8
1.0
1.2
20
40
60
80
100
120
140
160
180
200
S S +
2%RM
S +
5%RM
W W +
2%RM
W +
5%RM
Cd conc. (mg/kg)
Zn conc. (mg/kg)
Treatment
Fig. 5 Zn and Cd accumulation in S. alba plants on red mud (RM)-treated soil (S) and mine waste (W); concentrations given
in milligrams per kilogram plant dry weight
1244 Water Air Soil Pollut (2012) 223:1237–1247 comparison, the Hungarian Quality Criteria for animal fodder (FVM Decree 44/2003) are Cd, 1 mg/kg; Pb,
10 mg/kg; and As, 2 mg/kg, and the Hungarian
Quality Criteria for fresh vegetables (EüM Decree 17/ 1999) are Cd, 1 mg/kg; Pb, 3 mg/kg; As, 2 mg/kg;
and Zn, 100 mg/kg. The untreated mine waste levels of Zn and Pb exceed the criteria for fresh vegetables. The metal uptake of plants in the agricultural soil
was low, even in the untreated control, such that a maximum decrease of 23% in the Zn uptake was observed as a result of red mud treatment. For mine
wastes, the Cd and Zn uptake
decreased by 18% and
29%, respectively, after the
addition of 5% red mud.
The Zn uptake in waste or
soil remained above the
limit for fresh vegetables.
In the agricultural soil, a 2%
red mud addition
decreased the uptake of Pb
by 46% and the uptake of
As by more than 50%. The
addition of 2% red mud to
the mine waste resulted in a
49% decrease in Pb
uptake and a 79% decrease
in As uptake. However, a
5% red mud addition caused
increases in both Pb and
As concentrations in the test
plants, which resulted in
exceedances of limit for
animal fodder. This trend
was
observed during the first
sampling and remained
unchanged during the 2-year
experimental period
(results not shown) even
though the 5% red mud
addition resulted in the
largest decrease in metals
concentrations in the soil
solution. Gray et al. (2006)
also found that metal
concentrations in
field-grown,
21-month-old Festuca rubra
plants were higher for
the 5% red mud-treated plot
than for the 3% red
mudtreated
plot. They concluded that, in
addition to soil
factors, plant physiology
plays a role in regulating
metal uptake and
translocation. Lombi et al.
(2002b)
used various plants as
indicators and found that Pb
decreased in oilseed rape
leaves and wheat straw due
to red mud addition, while Pb
uptake increased in pea
leaves.
We used S. alba as an
indicator plant because
phytostabilization technology
focuses on using field
plants that do not accumulate
metals in shoots (or
above-ground parts) in order
to reduce the potential
transfer of metals to food
chain. For mine waste, where no agricultural use is planned, the metal
limits for food and fodder can be less rigorously applied.
4 Conclusions
Chemical stabilization combined with revegetation is an innovative, risk-based remediation technology that focuses on reducing the mobility of metals
rather than removing them. Metals remain in the
soil in an immobilized, non-water soluble, nontransportable,
and non-bioavailable form and,
therefore, pose less risk. In our experiments, red
mud from Almásfüzit?, Hungary was effective in reducing metal mobility in the contaminated soil
and mine waste.
The efficacy of red mud is dependent on the
type of soil/waste to be treated and on the amount and type of red mud added; therefore, microcosm and lysimeter testing are
necessary before field
application. Despite this, red
mud remains a viable
option as a chemical
stabilizer of toxic
metalcontaminated
soils.
The red mud applied in our
experiments, which is
stored in large quantities in
Hungary, has a low and
non-mobile toxic metal
content in comparison to
some other red muds. Our
study indicates that red
mud applied to agricultural
soil does not negatively
affect plants and soil
microbes and decreases the
amounts of mobile metals.
One possible conclusion is
that accidental spills of up to
5% red mud may not be
harmful to soil. Gruiz et al.
(2012) drew a similar
conclusion during their risk
assessment of a red mud
spill at Ajka. The use of red
mud for soil remediation
has the added benefit of
decreasing the amounts of
stored red mud, which
reduces the risks posed to
humans and the
environment.
As
Pb
5
10
15
20
25
0.0
0.5
1.0
1.5
2.0
2.5
3.0
S S +
2%RM
S +
5%RM
W W +
2%RM
W +
5%RM
Pb conc. (mg/kg)
As conc. (mg/kg)
Treatment
Fig. 6 As and Pb
accumulation in S. alba
plants on red mud
(RM)-treated soil (S) and
mine waste (W); concentrations given
in milligrams per kilogram plant dry weight
Water Air Soil Pollut (2012) 223:1237–1247 1245 Acknowledgments The research work was performed with
the financial support of the ―DIFPOLMINE‖ EU Life 02 ENV/
F000291 Demonstration Project, funded by the EU (www.
https://www.sodocs.net/doc/162184493.html,); the ―BANYAREM‖ Hungarian GVOP (Economic Competitiveness Operative Programme) 3.1.1-2004-05- 0261/3.0-R&D Project, funded by the Hungarian Ministry of
Economics and Transport and co-financed by the EU within the
European Plan (https://www.sodocs.net/doc/162184493.html,/Projects); and the ―MOKKA‖Hungarian R&D Project, NKFP (National Research and
Development Programme) 020-05, funded by the
National
Office of Research and
Technology
(www.mokkka.hu). Thanks
also to ágota Atkári, Zoltán
Sebestyén, Dániel Tuba,
Gáspár
Nagy, Zsuzsanna Bertalan,
and Felícián Gergely for their
contributions.
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赤泥作为化学稳定剂解决土壤有毒金属污染
摘要:我们进行了2年的在稳定矿山废弃物污染和农业土壤研究,以评估成效,铝土矿加工的副产品—赤泥。我们的研究位于Almásfüzit?,Hungarywith,作为长期处置区,赤泥pH值9.0。每增加5%(按重量)的赤泥,在农业土壤镉和锌的水提取去除减少了57%和87%,在废矿中分别为73%和79%。在实验室蒸渗仪研究中,赤泥渗滤液中镉和锌的浓度约为原来的三分之一。渗滤液金属含量低于最大的地表水的影响。以匈牙利附近山谷中的金属污染区域的风险评估确定的标准为标准。添加赤泥处理后的矿井废水和土壤中的毒性没有增加,芥测试厂镉和锌吸收降低18-29%。这些结果表明,赤泥应用于农业土壤对植物和土壤中的微生物产生任何负面影响,并降低移动金属的含量,从而表明其对土壤的修复价值。
关键词:赤泥,化学稳定,金属土壤,废矿
1引言
赤泥是铝土矿加工副产品,一般含有大量的Fe2O3(41%)和Al2O3(16%),少量的SiO2(10%),曹(9%)和Na2O(4%)和其他贵重金属,如钛(二氧化钛,9%)(Klauber等人,2009年),呈碱性。赤泥作为废物处理,根据铝土矿加工方法通常存储在大型泻湖或陆上处置坑中。2011年估计,2007年全球存储赤泥2.7亿吨,每年增加约120万吨,而每年约有50万吨存储在匈牙利(www.mti.hu)泻湖。这种类型的高容量存储,可导致环境灾
难:在2010年的秋天,一个红色的泥浆存储泻湖大坝失败和淤泥100万立方米的洪水淹没面积,致使奥伊考造成十人死亡和数百房屋破坏。
klebercz等人(2010)强调,赤泥应被视为一个有价值的材料和可利用品,因为它有许多潜在的重用应用程序,这可能有助于减少所需的存储量。具有潜在的建设和化学应用,包括建筑的用途,催化剂载体,陶瓷,塑料,涂料或颜料。冶金应用包括主要在金属,炼钢,恢复使用,炉渣和农艺性状的应用作为土壤改良剂,包括使用水及废物处理,气体洗涤等,(Klauber 等2009)。例如,赤泥在土壤中的应用,可以潜在地减少河流的富营养化,尤其是磷酸盐贫瘠的沙质土壤,(1993年)处理80吨/公顷瓦解废石膏和磷的损失减少70%的赤泥的沙质土壤。萨默斯(1993)的结论是,中和石膏应用于牧场是不必要的,小于100吨/公顷。(1996)建议最佳的赤泥应用率10-20吨/公顷(不含石膏),以减少磷的浸出,并指出,施用后至少5年的不断改进营养保留。
赤泥也可应用于土壤固定金属化学稳定性。菲利普斯(1998)发现,赤泥混合成砂具有更大的能力来SORB对Cu2+和Pb2+和Zn2+离子比沸石和磷酸三钙。米勒和Pluquet(1998)表明,赤泥可以减少50%可溶性锌,镉量减少20-50%的植物吸收金属。然而,在田间试验中,他们观察到,在植物和土壤中的重金属含量较低的固定功效。他们结论是,在实验中使用的赤泥中的铬和铝的浓度过高,这使得它不适合土壤修复。相比之下(2006)使用了1377毫克/公斤,在土壤中的金属稳定的铬浓度赤泥,并指出,植物入土壤混合时铬是不溶的。虽然这个问题可能是重要的含Cr红色泥浆,有一个红色泥浆的数量,不含有铬或其他有毒金属。
lombi等人(2002年a,b)赤泥的镉,铅,锌,铜,镍污染土壤的稳定性能,beringite发现,在土壤中的孔隙水都是同样有效地减少了金属的浓度。事实上,只有2%(W / W)赤泥为5%(W / W)有效;同时,土壤微生物生物量显着增加赤泥的存在。从交换(离子)在土壤中的氧化铁含量,这可能导致在金属流动更耐用,表明,赤泥(2005)(Mosonmagyaróvár,匈牙利),可以降低铵硝酸盐提取,水提取,生物利用锌,镉,但不影响铅。在田间试验中,用5%的赤泥、灰等(2006年)发现金属(70-96%),有效减少土壤中的锌,镉,镍等。前5个月无明显铅减少现象,到了第25个月,进入固定铅阶段。
friesl等人。(2004年,2006年,2009年)进行了几个盆栽和田间试验。其2004年的结果类似那些Lombi等。(2002a)的,但他们也发现,赤泥在5%
(W / W)应用增加了铵硝酸盐,由于土壤中的铜,铬,至五提取。在其2006年的田间试验,他们发现,赤泥应用土壤表面以下约15厘米,可以减少高达99%提取的硝酸铵,镉,锌,和铅,但为减少植物金属吸收可能需要更深层次的应用。最后,在2009年中,Friesl等。得出的结论是红泥和碎石污泥(细粒度的砂石业的废旧产品的40-65%二氧化硅,氧化铝10-14%3-7%的氧化铁,CaO的5-12%,与4-6%氧化镁组成pH值8.2),不含金属大麦品种(大麦distichon SSP。研究)相结合,进行最有效的金属污染土壤稳定实验。
赤泥废矿和金属污染土壤的申请已被集成到一个复杂的风险管理活动,是在一个大流域将实施的风险降低措施之一。复杂的整治理念,涉及的点源和治疗相结合的化学稳定性和植物稳定(Gruiz等al.2009a)弥漫性污染的清除。要找到合适的赤泥浓度和植物相结合,一些研究人员进行实验室土壤缩影实验(费格尔等人,2007年,2009年,2008年安东和巴纳)。
本文中所描述的实验,介绍了使用化学稳定/固定由植物稳定赤泥金属污染土壤的修复。2年的研究着重于在实验室土壤缩影中的长期结果。
2材料和方法
2.1材料
在2年的研究中,我们评估从,匈牙利Almásfüzit?的红泥有毒金属污染土壤和铅,锌硫化物(Gruiz等。2009a的)矿山废弃物的稳定性能。―almásfüzit?赤泥具有最红的泥浆,一般pH值约11.3(Gr?fe2009年等)。相比相对较低的pH值9.0,Almásfüzit?红色泥也有有毒金属含量低(低于污水污泥对土壤中的应用匈牙利的质量标准,在政府法令的第50/2001号规定中)相比,高碱性红色泥浆一些高铬含量在第1节讨论研究。
土壤源于矿农区下游,大量有毒金属,尤其是移动镉和锌污染的土壤。污染严重水浸,是由于废弃的矿井运输金属的结果。暴露这些发现部分废物已超过40年的风化,导致酸化,浸出,由氧化型向集约型发展。
2.2土壤处理
我们的测试样本包括2公斤塑料花盆中作三个样品。测试样本包括控制(无修正)矿山废弃物和受污染的土壤,进行2%和5%的(W / W)赤泥混合。所有在25℃下,混合培养,其保水能力为60%,每两个月采样后浇水。土壤采样和分析复杂的化学和生物过程。短期的变化进行了监测抽样在0,10,20,后9个月和2年的监测后45天内修订,并长期影响。
2.3综合监测
我们使用集成物理化学分析和生态毒性测试方法,在修订后的土壤样品
监测减少流动性,溶解性,有毒金属的生物利用度(Gruiz等。2005年,2009B)(图1)。我们评估化学分析和毒性测量的结果,以确定是否可以减少赤泥此外的流动性,生物利用度,并在土壤中的污染物所造成的风险,因此,赤泥是否可以用来作为稳定剂。gruiz等人(2005)推测,由各种金属和它们的物种混合构成的实际风险,可以更好地通过测量不利的生物效应及其毒理学特点。植物毒性和生物累积测量进行了表征赤泥之间的动态相互作用,治疗介质和生物体,并提供前和整治后的污染物的实际不利影响的直接信息。
2.3.1样品制备
准备综合监测,要求空气干燥,并的土壤样品土壤样品过筛(2 mm筛),根据匈牙利标准21470-50:2006。
2.3.2化学分析
为了预测移动金属浓度,我们用匈牙利标准HS21978-9:1998和分析蒸馏水提取物(pH值7.0;1:10土壤萃取率;搅拌4小时,25°C)和醋酸铵提取液(pH值4.5;1:10土壤萃取的比例,搅拌4小时,25°C)。我们由于使用氢氧化钠和碳酸钠提取物其浓度的流动性特征(pH值7.5;1:20土壤萃取比1:0.56摩尔在90小时1℃)(HS21470-50:2006)。我们测量后,王水消化(3:1盐酸,硝酸酸比1:4土壤萃取比2?在25°C;微波消解)的总重金属含量(HS21470-50:2006)。最后,我们决定使用ULTIMA 2(HORIBA Jobin Yvon 公司,法国)(HS21470-50:2006)与电感耦合等离子体原子发射光谱(ICP-AES法)提取所有的金属含量。
我们测量的金属平均每年在由RISSAC(2006年)开发的微型蒸渗仪修订土壤浸出。以确定2年的实验结束,我们使用了丝绸彩旗Wittetype板覆盖上一个Schachtschabel型玻璃柱的底部放置(内径31毫米)。磨碎,过筛土壤200克(1毫米筛)从原来的测试样品。我们模拟使用10.16毫米氯化钙溶液组成的雨,润湿与氯化钙溶液其最大的保水能力,并平衡他们48小时的列。我们在超过3周的期间内仿照1年的降雨量,加入12的氯化钙溶液50毫升等分的分数。我们为Gy?ngy?soroszi地区,估计每年降雨量为756毫米/年1982年和2002年(从匈牙利国家气象局的数据)之间。我们确定的渗沥液使用的金属含量ICP-AES法(HS21470-50:2006)。
2.3.3生物和生态毒理学的测量
我们选择毒性测试芥(白芥)。使用根和新梢生长抑制试验,由Gruiz 等。(2001年)开发,改用匈牙利标准21976-17:1993(废物育苗工厂测试)与土壤直接接触,以及创新的为期5天的生物蓄积性测试,我们这项研究的
2011高教社杯全国大学生数学建模竞赛 承诺书 我们仔细阅读了中国大学生数学建模竞赛的竞赛规则. 我们完全明白,在竞赛开始后参赛队员不能以任何方式(包括电话、电子邮 件、网上咨询等)与队外的任何人(包括指导教师)研究、讨论与赛题有关的问 题。 我们知道,抄袭别人的成果是违反竞赛规则的, 如果引用别人的成果或其他 公开的资料(包括网上查到的资料),必须按照规定的参考文献的表述方式在正 文引用处和参考文献中明确列出。 我们郑重承诺,严格遵守竞赛规则,以保证竞赛的公正、公平性。如有违反 竞赛规则的行为,我们将受到严肃处理。 我们参赛选择的题号是(从A/B/C/D中选择一项填写): A 我们的参赛报名号为(如果赛区设置报名号的话): 所属学校(请填写完整的全名):重庆交通大学 参赛队员 (打印并签名) :1. 陈训教 2. 范雷 3. 陈芮 指导教师或指导教师组负责人 (打印并签名):胡小虎 日期:2011 年9 月 12日赛区评阅编号(由赛区组委会评阅前进行编号):
2011高教社杯全国大学生数学建模竞赛 编号专用页 赛区评阅编号(由赛区组委会评阅前进行编号): 评 阅 人 评 分 备 注 全国统一编号(由赛区组委会送交全国前编号): 全国评阅编号(由全国组委会评阅前进行编号):
城市表层土壤重金属污染分析 摘要 本文针对城市表层土壤重金属污染做出了详细的分析,对于本题中所提出的问题一,我们利用MATLAB软件对所给的数值进行空间作图,然后分别作出了八种重金属元素的空间分布特征,然后,我们利用综合指数(内梅罗指数)评价的方法,对五个区域进行了综合评价,得出结果令人满意。对于问题二,我们根据第一问和题目所给的数据进行综合分析,得出了重金属污染的主要原因来自于交通区含铅为主的大量排放,和工业区污水的大量排放等等。对于问题三,我们通过对问题一中的八张重金属元素空间分布的图可以看出,发现大多数金属都呈中心发散性传播,同时经过分析,我们发现,如果考虑大气传播和固态传播,很难得出结论,在交通区,由于是汽车尾气造成的传播,发现重金属的传播无规律可循等,所以,我们考虑液态形式的传播,以针对地表水污染物的物理运动过程,以偏微分方程为建模基础,通过和假设和模型参数的估计,得出了可能污染源位置,最后,我们对模型进行了稳定性检验即灵敏性分析和拟合检验,发现在参数变化在10%左右,模型的稳定性良好。最后我们全面分析了模型的优缺点,,最后可以用MATLAB软件得出相应的结果。为更好地研究城市地质环境的演变模式,测定污染源范围还应收集该地区的每年生活、工业等重要污染源的垃圾排放量,地下水流动方向以及每年的生物降解量,降雨量对重金属元素扩散的影响。一但有污染证据,我们可以在该污染源附近沿地下水流动方向设定更多采样点,由此,我们可以构造一个三维公式来计算污染物质浓度的浮动就可以模拟三维空间内的重金属分布影响。 关键字:表层土壤重金属污染 MATLAB 内梅罗指数偏微分方程稳定性检验灵敏性分析地质演变生物降解量
土壤重金属污染 摘要:随着现代工业的发展,工业排出的污染物越来越多,土壤的重金属污染就是一个例子,土壤污染对人类的身心都造成了巨大的危害。本文主要就土壤重金属的概念、来源种类、特点危害、采样检测、防治修复等方面都做了一定的阐述。 With the development of modern industry, industrial discharge pollutants is more and more, soil heavy metal pollution is one example, soil pollution has caused great harm on human body and mind . This paper discusses the concept, origin of soil heavy metal types and characteristics, sampling testing and prevention harm repair all aspects were discussed as well。 关键词:土壤污染,重金属,危害 据报道,目前我国受镉、砷、铬、铅等重金属污染耕地面积近 2000 万公顷,约占总耕地面积的 1/5,其中工业“三废”污染耕地 1000 万公顷,污水灌溉的农田面积已达 330 多万公顷。例如:某省曾对 47 个县和郊区的 259 万公顷耕地(占全省耕地面积的五分之二)进行过调查。其结果表明,75% 的县已受到不同程度的重金属污染的潜在威胁,而且污染趋势仍在加重。 一土壤重金属污染的定义 重金属系指密度4.0以上约60种元素或密度在5.0以上的45种元素。但是由于不同的重金属在土壤中的毒性差别很大,所以在环境科学中人们通常关注锌、铜、钴、镍、锡、钒、汞、镉、铅、铬、钴等。砷、硒是非金属,但是它的毒性及某些性质与重金属相似,所以将砷、硒列入重金属污染物范围内。由于土壤中铁和锰含量较高,因而一般不太注意它们的污染问题,但在强还原条件下,铁和锰所引起的毒害亦应引起足够的重视。 土壤重金属污染是指由于人类活动将重金属带入到土壤中,致使土壤中重金属含量明显高于背景含量、并可能造成现存的或潜在的土壤质量退化、生态与环境恶化的现象。[1] 如下图为土壤环境质量标准值(GB15618—1995)单位: mg/kg
(19)中华人民共和国国家知识产权局 (12)发明专利申请 (10)申请公布号 (43)申请公布日 (21)申请号 201910365200.X (22)申请日 2019.04.30 (71)申请人 湖南省和清环境科技有限公司 地址 410001 湖南省长沙市高新区麓松路 459号东方红小区延农综合楼14楼 CYY-291房 (72)发明人 娄伟 王琦 刘天伦 李文博 肖启学 (74)专利代理机构 贵阳中新专利商标事务所 52100 代理人 胡绪东 (51)Int.Cl. C09K 17/06(2006.01) B09C 1/08(2006.01) C09K 109/00(2006.01) (54)发明名称 一种砷、镍复合污染场地土壤修复稳定剂及 其处理方法 (57)摘要 本发明公开了一种砷、镍复合污染场地土壤 修复稳定剂及其处理方法,包括以下成分及其配 比:含量为5 wt%的硫酸亚铁溶液、氢氧化钙溶液 和水,硫酸亚铁溶液中硫酸亚铁为FeSO 4?7H 2O, 硫酸亚铁溶液体积和待处理污染土壤质量比例 为0.3:100-0.5:100,加入的氢氧化钙溶液量为 确保待处理污染土壤的pH为6-8,加入的水量确 保土壤含水率为35-45%。本发明硫酸亚铁配合氢 氧化钙调节pH处理砷、镍污染场地污染土壤,不 仅降低成本,而且制备和使用方法简单。相比其 他方法,效果更好,与市面上其他相同效果的药 剂相对比,硫酸亚铁成本会下降能达到300%以 上,采用水剂施加,药剂与土壤接触更充分,养护 处理时间缩短了2/3,而且充分反应,处理效果更 佳。权利要求书1页 说明书8页 附图2页CN 110079323 A 2019.08.02 C N 110079323 A
简述土壤污染及其 防治措施
结课论文 题目:简述土壤污染及其防治措施姓名:程旭 院系:生命科学学院农学系 年级专业:级园艺专业 学号:
指导教师:王玉芬 12月31日 摘要 本文在综述中国土壤环境污染态势及成因的基础上,提出了土壤环境污染的预防、控制和修复方法。指出了当前中国土壤环境污染态势严峻,危及粮食生产、食物质量、生态安全、人体健康以及区域可持续发展。认为以预防为主,预防、控制和修复相结合是中国在相当长时期内的土壤环境保护策略。 关键词:土壤污染,预防,控制,修复
引言 土壤是农业生产的基础,是人类赖以生存的基石,也是人类食物与生态环境安全的保障。但随着经济的发展,全球土壤资源承受的因人口增长、植被破坏、生物多样性消失、土壤退化、气候变化和污染种种等的压力逐渐增大。 土壤是生态环境的重要组成部分。是结合无机界和有机界的纽带,是联系其它要素的关键环节,是人类赖以生存、发展的主要自然资源之一。但由于现代工农业生产的飞跃发展,有的地方农药、化肥过度使用。工矿企业固体废弃物向土壤倾倒和堆放,城市污水、工业废水、大气沉降物也会进入土壤,使土壤污染日益严重。土壤污染是全球三大污染问题之一。不断恶化了的土壤污染态势,已经成为影响中国可持续发展的重大障碍,防治土壤污染刻不容缓。 1土壤污染的含义和特点 1.1 土壤污染的含义 土壤是指陆地表面具有肥力、能够生长植物的疏松表层,其厚度一般在2 m左右。土壤不但为植物生长提供机械支撑能力,并能为植物生长发育提供所需要的水、肥、气、热等肥力要素。近年来,由于人口急剧增长,工业迅猛发展,固体废物不断向土壤
生物技术修复土壤重金属污染 任课教师:XXX 姓名:XXX 学号:XXX 专业:生物科学基地班 年级:XXX 学院:生命科学学院 成绩______________________
土壤重金属污染 摘要:随着社会经济特别是重工业的发展,土壤重金属污染的形势也越来越严峻。污染治理已成备受关注的焦点。已有许多物理工程、化学修复、生物修复等技术相继涌现。本文就土壤重金属污染的现状、现有生物修复技术做综述。 关键词:重金属污染现状修复技术 Abstract:With the development of social economy especially heavy industry, the situation of soil heavy metal pollution is becoming more and more control has become the focus of the are many physics engineering, chemical remediation, bioremediation technology have article reviews the current situation, the existing soil heavy metal pollution bioremediation technology. Keyword:Heavy metal pollution status quo Technology to repair 前言:随着工农业的发展,土壤重金属污染问题日益严重,土壤中过量的重金属会被植物吸收到体内,通过食物链和生物富集作用对人体健康造成巨大危害。治理土壤环境重金属污染问题已成为当今的研究热点,而物理化学修复手段显然不能快速高效地解决这一难题,生物修复因其廉价、环境友好而备受青睐。[1] 1.现状 国内重金属污染现状 重金属资源是国民经济发展的基础和重要组成部分,一方面重金属资源的开发为我国社会经济的快速发展做出了巨大的贡献,另一方面大量的重金属资源开发活动势必造成严重的重金属污染,尤其是乡镇、个体矿山的开发,由于其各方面的技术、设备简陋,环保意识缺乏等原因对环境的破坏和污染是特别严重,甚至引发严重的环境污染事件,直接威胁到人类的生命安全. 中国的土壤重金属污染已较为严重和普遍,污染源主要是污灌、金属矿开采、冶炼与
第23卷第2期2005年5月 贵州师范大学学报(自然科学版) Journa l of Guizhou Nor m al University(Natural Sciences) Vo.l23.No.2 M ay2005 文章编号:1004)5570(2005)02-0113-08 土壤中重金属环境污染元素的来源及作物效应 王济1,王世杰2 (1.贵州师范大学地理与生物科学学院,中科院地化所环境地球化学国家重点实验室,中科院研究生院贵州贵阳550002; 2.中科院地化所环境地球化学国家重点实验室,贵州贵阳550002) 摘要:主要介绍我国5土壤环境质量标准6中规定含量的8种重金属环境污染元素(汞、镉、铅、铬、砷、锌、铜、镍)的污染来源及作物效应。土壤中重金属的主要来源是成土母质,矿山开采的三废污染,大气中重金属的沉降,农药、化肥、塑料薄膜等的使用等。重金属在作物中的分布规律一般是根>茎>叶>籽实。 关键词:土壤;重金属;环境;污染;来源;作物效应 中图分类号:X53文献标识码:A The sources and crops effect of heavy m eta l ele m en ts of con ta m i na ti on i n soil WANG Ji1,WANG S h i2ji e2 (1.Gu iz hou Nor ma lUn i ve rs i ty,The State Key Laboratory of Enviro nmenta lGeochem istry,Institute of Geochem i stry,Graduate School of Ch i nese A cade m y of Sc i ences,Guiyang,Gu i zho u550002,Ch i na; 2.The S tate Key Laboratory of Environ m en tal Geoche m istry,Instit ute of Geoche m istry, Chinese A cade m y of Sc i ences,Guiyang,Gu i zho u550002,Ch i na) Abstr act:Th is paper has intr oduced t h e source and crops eff ect of heavymetal e le ments of conta m i n a2 ti o n(H g,Cd,Pb,Cr,A s,Z n,Cu,N i)li m ited by Environmental Qua lity Standar d f or Soils (GB1561821995).The ma i n source is f ro m mother2materi a l of soi.l The heavy meta ls polluti o n also can be related w ith the produce ofm iner,sedi m en tation of heavy me tals in at m osphere,use of agro2 che m icals etc.The distri b uti o na l or der in crops i s root>ste m>leaf>f rui.t K ey w ord s:soi;l heavy meta;l environmen;t pollution;source,crop e f fect 土壤中重金属污染元素主要包括汞、镉、铅、铬及类金属元素砷等生物毒性显著的元素,以及有一定毒性的锌、铜、镍等[1]。因此我们将汞、镉、铅、铬、砷、锌、铜、镍合称为重金属环境污染元素。人类活动将重金属加入到土壤中,致使土壤中重金属含量明显高于原有含量,并造成生态环境质量恶化的现象称为土壤重金属污染[2]。重金属污染物在土壤中移动性很小,不易随水淋滤,不被微生物降解[3,4]。它们一方面对农作物、农产品和地下水等许多方面产生重大影响,并通过食物链危害人体健康;另一方面因大多数重金属在土壤中相对稳定且难以迁出土体,对土壤理化性质及土壤生物学特性(尤其是土壤微生物)和微生物群落结构产生明显不良影响,从而影响土壤生态结构和功能的稳定性[2,5]。 113 收稿日期:2005-01-04 基金项目:贵州省高校发展专项资金(黔教科2004111),贵州师范大学校科研启动费资助项目。作者简介:王济(1975-)男,博士,研究方向:土壤与环境。
论文课题土壤重金属污染现状及其治理方法 小组组长12549025 李思远 小组成员12549026 李康 12549028 王鑫 12549030 吴义超 土壤重金属污染现状及其治理方法随着社会的快速发展,土壤重金属污染日益严重。针对此,涌现了许多修复技术,而生物修复前景广阔,正日益受到重视。 现代工农业等快速发展的同时,土壤重金属污染的形势也越来越严峻。其治理方法很多,而生物修复以其无可比拟的优势正受到关注,应用前景广阔。但生物修复仍存在许多问题待解决,如超积累植物吸收重金属的机理还未研究清楚。所有这些,都阻碍了生物修复的大规模应用。 土壤重金属污染是指土壤中重金属过量累积引起的污染。污染土壤的重金属包括生物毒性显著的元素如Cd、Pb、Hg、Cr、As,以及有一定毒性的元素如Cu、Zn、Ni。这类污染范围广、持续时间长、污染隐蔽、无法被生物降解,将导致土壤退化,农作物产量和质量下降,并通过径流、淋失作用污染地表水和地下水。过量重金属将对植物生理功能产生不良影响,使其营养失调。汞、砷能抑制土壤中硝化、氨化细菌活动,阻碍氮素供应。重金属可通过食物链富集并生成毒性更强的甲基化合物,毒害食物链生物,最终在人体内积累,危害人类健康。 1现状 1.1国内
国家环境保护部抽样监测30万公顷基本农田保护区土壤,发现有3.6万公顷土壤重金属超标,超标率达12.1%。 据国土资源部消息,目前全国耕地面积的10%以上已受重金属污染,约有1.5亿亩,污水灌溉污染耕地3250万亩,固体废弃物堆积占地和毁田200万亩,其中多数集中在经济相对发达地区。 据我国农业部调查数据,在全国约140万公顷的污灌区中,受重金属污染的土地面积占污灌区面积的64.8%,其中轻度污染46.7%,中度污染9.7%,严重污染8.4%。 华南部分城市50%的耕地遭受镉、砷、汞等有毒重金属污染;长三角地区有些城市大片农田受多种重金属污染, 10%的土壤基本丧失生产力。 2005年,长三角等地土壤重金属污染严重的情况,曾见诸报端,并引发舆论普遍关注和争议。土壤污染立法迫在眉睫。 对浙北、浙东和浙中的236.5万公顷农用地调查发现,不适合种农作物的农用地面积为47.2万公顷,占20%;浙北、浙中、浙东沿海三个区域中,属轻度、中度与重度重金属污染的面积分别占38.12%、9.04%、1.61%,城郊传统的蔬菜基地、部分基本农田都受到了较严重的影响。 第九届亚太烟草和健康大会中一项名为《中国销售的香烟:设计、烟度排放与重金属》的研究报告称:13个中国品牌国产香烟中铅、砷、镉等重金属成分含量严重超标,其含量最高超过拿大产香烟3倍以上! 2009年8月,陕西凤翔县发现大量儿童血铅含量严重超标,后确认是附近的陕西东岭冶炼公司的铅排放所导致。 1.2国外 英国早期开采煤炭、铁矿、铜矿遗留下的土壤重金属污染经过300年依然存在。1996到1999年间,英格兰和威尔士尝试挖出污染土壤并移至别处,但并未根本解决问题。从20世纪中叶开始,英国陆续制定相关的污染控制和管理的法律法规,并进行土壤改良剂和场地污染修复研究。 日本的土地重金属污染在上世纪六七十年代非常严重。其经济的快速增长导致了全国各地出现许多严重环境污染事件,被称为四大公害的痛痛病、水俣病、第二水俣病、四日市病,就有三起和重金属污染有关。 荷兰在工业化初期土地污染问题严重。从20世纪80年代中期开始,加强土壤的环境管理,完善了土壤环境管理的法律及相关标准。国土面积4.15万平方
土壤污染及防治 摘要:土壤污染对我国社会经济发展,生态环境,食品安全和农业可持续发展构成严重威胁,并危害人体健康,但污染防治基础相当薄弱。通过对土壤的组成、重要性、土壤污染物、污染源以及土壤现状、土地污染的危害加以分析,揭示土壤污染防治的必要性,提出加强土壤污染防治等。 关键词:土壤组成;重要性;土壤污染;防治 土壤是陆地表面能够生长植物的疏松表层,是地球上生命活动不可缺少的重要物质。由于污染,土壤的营养功能,净化功能,缓冲功能和有机体的支持功能正在丧失,土壤污染呈继续扩大的趋势[1]。因此,了解土壤的组成等信息,清除被称为“化学定时炸弹”的土壤污染,采取有效措施防治土壤污染对于合理利用土地、保护人民身体健康、提高人民生活质量具有极其重要的作用。 1土壤的组成及其重要性 1.1土壤的组成 土壤是由固体、液体和气体三相共同组成的多相体系。土壤固相主要由矿物质以及有机质组成,土壤气相和液相填充于土骨架之间的孔隙中[2]。 1.1.1土壤矿物质 土壤矿物质在土壤中起着支撑的作用,人们很形象的称之为“土壤的骨骼”。 土壤矿物质是岩石经过物理风化和化学风化形成的。按成因类型可将土壤矿物分为两类:原生矿物和次生矿物。 土壤中最主要的原生矿物有四类:硅酸盐类矿物、氧化物类矿物、硫化物类矿物和磷酸盐类矿物。而次生矿物通常根据其结构和性质分为三类:简单盐类、三氧化物类和次生铝硅酸盐类[3]。 1.1.2土壤有机质 土壤有机质(SOM)是泛指以各种形态和状态存在于土壤中的各种含碳有机物。具体地说,它包括土壤中的动物、植物及微生物残体的不同分解、合成阶段的各种产物,它是土壤中细小的非生命体形式的天然有机物的总称,实质上包
土壤重金属污染固化/稳定化治理技术 一、基本概念 固化/稳定化土壤修复技术指运用物理或化学的方法将土壤中的有害污染物固定起来,或者将污染物转化成化学性质不活泼的形态,阻止其在环境中迁移、扩散等过程,从而降低污染物质的毒害程度的修复技术。 固化/稳定化技术与其他修复技术相比,有费用低、修复时间短、可处理多种复合重金属污染、易操作、适用范围较广等优势,因此,美国环保署将固化/稳定化技术称为处理有害有毒废物的最佳技术。 二、常用的固化/ 稳定化技术系统 目前,常用的固化/ 稳定化技术主要包括以下几种类型:(1)水泥、石灰、粉煤灰等无机材料固化;(2)沥青、聚乙烯等热塑性有机材料和脲甲醛、聚酯等热固性有机材料固化;(3)玻璃化技术;(4)硫酸亚铁、磷酸盐、氢氧化钠、高分子有机物等药剂稳定化。由于技术和费用等方面的原因,以水泥、石灰、粉煤灰等无机材料为添加剂的固化/ 稳定化应用最广泛,占项目数的94%,在项目中使用无机-有机复合添加剂的占项目数的3%。 1、水泥固化 水泥基粘结剂是固化技术普遍使用的材料。在过去的50 年里水泥固定化处理重金属技术被广泛使用。水泥是一种无机胶结材料,经过水化反应后可以生成坚硬的水泥固化体。水泥固化的机理主要是在水泥的水化过程中,重金属可以通过吸附、化学吸收、沉降、离子交换、钝化等多种方式与水泥发生反应,最终以氢氧化物或络合物的形式停留在水泥水化形成的水化硅酸盐胶体表面,同时水泥的加入也为重金属提供了碱性环境,抑制了重金属的渗滤。 水泥的种类很多,包括普通硅酸盐水泥、矿渣硅酸盐水泥、矾土水泥、沸石水泥等都可以作为废物固化处理的基材,其中最常用的是普通硅酸盐水泥。影响水泥固化的因素很多,为达到满意的固化效果,在固化操作过程中要严格控制水灰比、水泥与废物比、凝固时间、添加剂和固化块的成型条件等工艺参数。如果被处理废物中含有妨碍水合作用的物质,仅用普通水泥处理就存在强度不大、物理化学性能不稳定等问题,需加入适当的添加剂,以吸收有害物质并促进其凝固,并降低有害组分的溶出率。活性氧化铝具有助凝作用,是常用的添加剂,
土壤重金属污染状况及修复 中文摘要:重金属污染因具有毒性、易通过食物链在植物,动物和人体内累积,对生态环境和人体健康构成严重威胁。随着工业快速发展、农药及化肥的广泛使用,农田土壤重金属污染越来越严重,研究农田土壤重金属污染现状及修复技术对农产品安全具有重要意义。综合国内外农田土壤重金属污染状况,农田土壤重金属污染主要来源于固体废弃物堆放及处置、工业废物大气沉降、污水农灌和农用物质的不合理施用。该文综述了国内外有关农田重金属污染土壤修复技术(物理修复、化学修复、生物修复、农业生态和联合修复)的研究进展,并针对各种修复方法,阐述了其原理、修复条件、应用实例及其优缺点,重点论述了植物修复的机理和应用,提出了草本与木本联合修复可有效提高农田土壤重金属复合污染的修复效率,为农田土壤土壤重金属复合污染修复提出了新的途径。最后在对已有研究分析的基础上,提出了联合修复技术(如生物联合技术、物理化学联合技术和物理化学—生物联合技术)可以在一定程度上克服使用单一修复手段存在的缺点,可提高复合污染的修复效率、降低修复成本,未来应深入探索联合修复技术间的相互作用机理,以期为农田土壤重金属综合治理与污染修复提供科学依据。 关键词:农田土壤;重金属;污染;修复技术 Abstract; Heavy metal pollution caused by toxic, easily in the food chain through plants, animals and humans in vivo accumulation of the ecological environment and pose a serious threat to human health. With the rapid development of industry, the widespread use of pesticides and fertilizers, agricultural soil heavy metal pollution is getting worse, research Soil Heavy Metal Pollution and Remediation Technology is important for the safety of agricultural products. Comprehensive Farmland Soil Heavy Metal Contamination at home and abroad, mainly from heavy metals in soils contaminated solid waste deposits and disposal of industrial waste atmospheric deposition, sewage unreasonable application of agricultural irrigation and agricultural materials. This paper reviews the related farmland abroad Heavy Metal Contaminated Soil Research Progress (physical restoration, chemical remediation, bioremediation, ecological agriculture and bioremediation) repair, and for a variety of repair methods, described its principle, to repair the condition, application examples its advantages and disadvantages, Focuses on the mechanism and application of phytoremediation, herbaceous and woody proposed bioremediation can effectively improve the efficiency of heavy metals in soils repair compound contaminated soil farmland soil heavy metals contamination fixes proposed a new way. Finally, the existing research and analysis based on the proposed joint repair techniques (such as bio-technology joint, joint technical and physical chemistry physical chemistry - Biotechnology United Technologies) can overcome the disadvantages of using a single repair means exist to some extent, can improve repair efficiency combined pollution, reduce repair costs, Future should further explore the mechanism of interaction between the United repair techniques, with a view to the comprehensive management of heavy metals in soils and pollution remediation provide a scientific basis. Keywords: Soil; heavy metal; pollution; repair technology 1 土壤中重金属的污染现状 土壤作为开放的缓冲动力学体系,在与周围的环境进行物质和能量的交换过程中,不可避免地会有外源重金属进入这个体系! 重金属对土壤的主要污染途径是工业废渣、废气 中重金属的扩散、沉降、累积,含重金属废水灌溉农田,以及含重金属农药、磷肥的大量施用! 外来重金属多富集在土壤的表层!.工业生产上重金属释放到环境中的主要途径有采矿、冶炼、燃
土壤重金属污染现状及其治理方法摘要随着社会的快速发展,土壤重金属污染日益严重。针对此,涌现了许多修复技术,而生物修复前景广阔,正日益受到重视。 关键词土壤重金属污染生物修复超积累植物 Abstract: With the rapid development of the society, the heavy metal pollution of the soil is growing worse and worse. Facing this situation, there have been many repairing technologies. The Bioremediation has a broad prospect and is at a premium. Keywords:heavy metal pollution of the soil;Bioremediation;hyper accumulator 现代工农业等快速发展的同时,土壤重金属污染的形势也越来越严峻。其治理方法很多,而生物修复以其无可比拟的优势正受到关注,应用前景广阔。但生物修复仍存在许多问题待解决,如超积累植物吸收重金属的机理还未研究清楚。所有这些,都阻碍了生物修复的大规模应用。 土壤重金属污染是指土壤中重金属过量累积引起的污染。污染土壤的重金属包括生物毒性显著的元素如Cd、Pb、Hg、Cr、As,以及有一定毒性的元素如Cu、Zn、Ni。这类污染范围广、持续时间长、污染隐蔽、无法被生物降解,将导致土壤退化,农作物产量和质量下降,并通过径流、淋失作用污染地表水和地下水。过量重金属将对植物生理功能产生不良影响,使其营养失调。汞、砷能抑制土壤中硝化、氨化细菌活动,阻碍氮素供应。重金属可通过食物链富集并生成毒性更强的甲基化合物,毒害食物链生物,最终在人体内积累,危害人类健康。 1现状 1.1国内 国家环境保护部抽样监测30万公顷基本农田保护区土壤,发现有3.6万公顷土壤重金属超标,超标率达12.1%。 据国土资源部消息,目前全国耕地面积的10%以上已受重金属污染,约有1.5亿亩,污水灌溉污染耕地3250万亩,固体废弃物堆积占地和毁田200万亩,其中多数集中在经济相对发达地区。 据我国农业部调查数据,在全国约140万公顷的污灌区中,受重金属污染的
十种土壤修复技术解析 1、原位固化/稳定化技术 原理:通过一定的机械力在原位向污染介质中添加固化剂/稳定化剂,在充分混合的基础上,使其与污染介质、污染物发生物理、化学作用,将污染土壤固封为结构完整的具有低渗透系数的固化体,或将污染物转化成化学性质不活泼形态,降低污染物在环境中的迁移和扩散。 适用性:适用于污染土壤,可处理金属类、石棉、放射性物质、腐蚀性无机物、氰化物以及砷化合物等无机物;农药/除草剂、石油或多环芳烃类、多氯联苯类以及二噁英等有机化合物。不宜用于挥发性有机化合物,不适用于以污染物总量为验收目标的项目。 2、异位固化/稳定化技术 原理:向污染土壤中添加固化剂/稳定化剂,经充分混合,使其与污染介质、污染物发生物理、化学作用,将污染土壤固封为结构完整的具有低渗透系数的固化体,或将污染物转化成化学性质不活泼形态,降低污染物在环境中的迁移和扩散。 适用性:适用于污染土壤。可处理金属类、石棉、放射性物质、腐蚀性无机物、氰化物以及砷化合物等无机物;农药/除草剂、石油或多环芳烃类、多氯联苯类以及二噁英等有机化合物。不适用于挥发性有机化合物和以污染物总量为验收目标的项目。当需要添加较多的固化/稳定剂时,对土壤的增容效应较大,会显著增加后续土壤处置费用。
3、原位化学氧化/还原技术 原理:通过向土壤或地下水的污染区域注入氧化剂或还原剂,通过氧化或还原作用,使土壤或地下水中的污染物转化为无毒或相对毒性较小的物质。常见的氧化剂包括高锰酸盐、过氧化氢、芬顿试剂、过硫酸盐和臭氧。常见的还原剂包括硫化氢、连二亚硫酸钠、亚硫酸氢钠、硫酸亚铁、多硫化钙、二价铁、零价铁等。 适用性:适用于污染土壤和地下水。其中,化学氧化可处理石油烃、BTEX(苯、甲苯、乙苯、二甲苯)、酚类、 MTBE(甲基叔丁基醚)、含氯有机溶剂、多环芳烃、农药等大部分有机物;化学还原可处理重金属类(如六价铬)和氯代有机物等。受腐殖酸含量、还原性金属含量、土壤渗透性、PH值变化影响较大。 4、异位化学氧化/还原技术 原理:向污染土壤添加氧化剂或还原剂,通过氧化或还原作用,使土壤中的污染物转化为无毒或相对毒性较小的物质。常见的氧化剂包括高锰酸盐、过氧化氢、芬顿试剂、过硫酸盐和臭氧。常见的还原剂包括连二亚硫酸钠、亚硫酸氢钠、硫酸亚铁、多硫化钙、二价铁、零价铁等。 适用性:适用于污染土壤。其中,化学氧化可处理石油烃、BTEX(苯、甲苯、乙苯、二甲苯)、酚类、 MTBE(甲基叔丁基醚)、含氯有机溶剂、多环芳烃、农药
受重金属污染的土壤修复方法 摘要:土壤的重金属污染已经成为不能忽视的危害人类健康的环境问题,本方案论述了受重金属镉污染的土壤修复技术,包括物理修复,化学修复,生物修复及联合修复的方法。 重金属元素是使农田受污染最普遍、生物毒性最强的,它在环境中的化学活性强、赋存形态多、移动性大、毒性持久,容易通过食物链的富集作用危及人类健康。因此,全面地了解土壤重金属镉污染现状、危害、赋存形态、迁移转化、有效性评价及治理方法对于采用新方法治理土壤镉污染,减弱其对作物的危害,实现土壤的可持续利用具有重要意义。 我国土壤重金属污染物超标情况,正式被确定为中国土壤的首要污染物。从不同的土地利用类型上看,镉是耕地的首要污染物,是林地、草地和未利用地的第二污染物。多地农作物镉超标,不仅造成巨大的经济损失而且严重危害居民健康,土壤重金属镉污染治理迫在眉睫。 土壤重金属污染是指由于人类活动将重金属引入到土壤中,致使土壤中重金属含量明显高于环境背景值,造成生态环境恶化的现象。工业生产中石油、矿物等的开采、冶炼加工及运输等过程,农业生产中污水灌溉、农药、劣质化肥等的不合理使用,城市生活中污水、污泥和垃圾等未经处理乱排、偷排等行为是造成土壤重金属污染的主要原因。逐渐成为全球性的环境问题。重金属对植物的毒性,在形态上主要表现为叶片失绿、卷曲,根、莲生长迟缓;生理方面多表现为蒸腾作用和光合作用受到抑制,引起氧化胁迫和膜的损伤等。植物体对重金属的吸收积累能够明显抑制其对韩、镁等矿物质元素的吸收和转运的能力,引起大量营养元素的缺乏和有效性降低。当植物体内重金属含量超过一定浓度后对叶绿素有破坏作用,并促进抗坏血酸分解,使游离脯氨酸积累,抑制硝酸还原酶活性,对植物体产生间接伤害。重金属也能对植物体产生直接危害, 土壤重金展污染的修复技术
土壤修复技术及优缺点 The Standardization Office was revised on the afternoon of December 13, 2020
土壤是植物生长繁育的自然基地,是农业的基本生产资料,是人类赖以生存的极其重要的自然资源。随着工业、城市污染的加剧和农用化学物质种类、数量的增加,土壤重金属污染日益严重。土壤重金属污染具有隐蔽性、长期性和不可逆性的特点。土壤中有害重金属积累到一定程度,不仅会导致土壤退化,农作物产量和品质下降,而且还可以通过径流、淋失作用污染地表水和地下水,恶化水文环境,并可能直接毒害植物或通过食物链途径危害人体健康。 不同污染类型的土壤污染,其具体治理措施不完全相同,目前,重金属土壤的修复技术主要有工程措施,物理化学方法,植物修复方法以及微生物修复方法。 工程措施主要包括客土、换土和深耕翻土等措施。通过客土、换土和深耕翻土与污土混合,可以降低土壤中重金属的含量,减少重金属对土壤-植物系统产生的毒害,从而使农产品达到食品卫生标准。深耕翻土用于轻度污染的土壤,而客土和换土则是用于重污染区的常见方法,在这方面日本取得了成功的经验。工程措施是比较经典的土壤重金属污染治理措施,它具有彻底、稳定的优点,但实施工程量大、投资费用高,破坏土体结构,引起土壤肥力下降,并且还要对换出的污土进行堆放或处理。 物理化学方法是当前重金属污染土壤修复研究的热点,也是最为成熟工程上应用最为广泛的修复技术,主要包括固化/稳定化技术,土壤淋洗技术,电动修复技术和电热修复技术等。 固化/稳定化技术是通过固态形式在物理上隔离污染物或者将污染物转化成化学性质不活泼的形态,从而降低污染物质的毒害程度。如通过施加水泥等固化土壤重金属的固化修复技术,或向土壤投入无机或有机改良剂,改变土壤的
解读:一种国外优异的环保、通用的土壤稳定剂 1.简介 福世蓝MB-217土壤稳定剂是一种环保的、通用的液体土壤添加剂,它与水混合,用于控制和管理不同的土壤条件,在应用量足够的条件下,MB-217土壤稳定剂会有效的消除或防止以下问题:铺砌的以及未铺砌的道路路基的破坏,粉尘污染、土壤腐蚀以及池塘和蓄水池的水流失。 2.应用范围及优势 铺砌道路的基层稳固:MB-217土壤稳定剂可用于对表面磨损有限制要求的任何类型的土壤基层的稳固作用,这包括道路、停车厂、飞机场跑道以及沥青、碎石封层,甚至是混凝土覆盖的其他类型的交通区域。 如图表所示(下图),实验测试显示出在土壤样品中加入MB-217土壤稳定剂能够使强度增加3000%! 水泥基稳固:通过美国德克萨斯交通部进行的现场测试显示了福世蓝MB-217土壤稳定剂的强度能够比得上水泥稳固,成本要低很多。当在土壤基层中用福世蓝MB-217土壤稳定剂进行补充和稳固时,水泥的使用量能够降低50%,最重要的是,在这个过程中水泥的性能得到大幅提高,同时成本节省了40%。福世蓝MB-217土壤稳定剂的可塑性特点能够与水泥产生一种柔性更大的基层,这会产生较低的水泥断裂临界值,从而极大的降低了维护成本。 老旧沥青路的再循环和稳定:对老旧沥青路的再循环是福世蓝MB-217土壤稳定剂的最佳应用之一,该产品是环保的,因此它可以代替这种将更多的沥青乳液注入土壤的不利于环境的方法。福世蓝MB-217土壤稳定剂是老旧沥青路现场冷再生的主要添加剂,将沥青粉碎
并将其与老旧基层进行原位混合的效果通过注入福世蓝MB-217土壤稳定剂得到了大幅的提高。 左边的土芯样本包含福世蓝MB-217土壤稳定剂和水泥。该样本是从德克萨斯东部由德克萨斯交通部进行稳定处理的公路上采集的。德克萨斯交通部的测试显示了与相同道路上仅仅使用水泥的部分相比,仅仅使用福世蓝MB-217土壤稳定剂就能够在道路路基上产生更高的强度。然而,将两种产品结合在一起,能够达到更好的效果,并且节省更多的成本。 未铺砌道路的稳定以及扬尘控制:用淡水来稳定未铺砌的道路和控制扬尘是一项永无止境的艰难任务,在昂贵投入下只不过提供了几个小时的回报。这是徒劳无益的,浪费时间和金钱,而且宝贵水资源用量增加,随着水的快速蒸发,污染云又再次释放到环境中。用淡水治理粉尘污染是浪费的、过时的方法,而用更加简便、成本更低的MB-217土壤稳定剂进行首次应用就可以解决这个问题,可以根据需要偶尔进行二次应用。用于粉尘控制的MB-217土壤稳定剂用量可以进行调整来满足所有交通条件下的恰当的要求。 垃圾填埋场防渗层稳固和土壤腐蚀控制:福世蓝MB-217土壤稳定剂有强大的能力使土壤几乎不渗水。图表将美国环保署的垃圾填埋场的渗透系数1x10-7与实验室确定的福世蓝MB-217土壤稳定剂的渗透系数2.9x10-9进行了比较。福世蓝MB-217土壤稳定剂多次满足并超出了美国环保署标准,因此使它成为垃圾填埋场复合防渗层的优良添加剂。垃圾填埋场的复合防渗层或者任何含有福世蓝MB-217土壤稳定剂的土壤筑堤将会转化成可以自身密封以防止液体渗透的固体膜。本来需要进行挖掘并进行替换的不达标的土壤可以用福世蓝MB-217土壤稳定剂进行处理,为垃圾填埋场拥有者节省了大量的成本。
天津师范大学 本科毕业论文(设计)重金属污染土壤的超积累植物修复技术 学院:城市与环境科学学院 学生姓名:陈晓龙 学号:10508122 专业:资源环境与城乡规划管理 年级:2010级 完成日期:2014年4月8日 指导教师:梁培玉
重金属污染土壤的超积累植物修复技术 摘要:近年来,由于工农业的急速发展,导致环境问题日益严重。采矿、冶炼、汽车尾气的排放、工业废水的排放、农业化肥的使用,导致重金属囤积,严重污染土壤,对人类生活已造成了严重危害。重金属污染有别于其他污染,在土壤中重金属无法通过自身特性而降解。由于重金属具的易富集的特性,这导致其很难被降解在环境中。植物修复技术作为一种新兴的绿色技术被重视,并成为国内外研究的热点。本文就国内外目前研究植物修复技术的现状,重点探讨中国在植物修复技术上的发展和植物修复技术目前在国内重金属污染土壤中的应用。 关键词:重金属;土壤污染;超积累植物;植物修复技术; Technology of Hyperaccumulator for Phytoremediation of Soils Contaminated by Heavy Metals Abstract:In recent years, given the rapid development of industry and agriculture, led to increasingly serious environmental problems. Mining, metallurgy, automobile exhaust emissions and industrial wastewater discharges, agricultural fertilizers, leading to accumulation of heavy metals, heavily polluted soil, has caused serious harm to human life. Differ from other organic compound pollution of soil heavy metal pollution, cannot by itself the purification and physicochemical properties or biological degradation. Enrichment of heavy metals, it is difficult to degrade in the environment. Phytoremediation was developed in recent years for removal of heavy metal pollution in soil in green technology. Hyperaccumulators and phytoremediation of heavy metals has become one of the hot fields of academic research at home and abroad. This article on the current status of research on phytoremediation technology at home and abroad, focusing on China's development in this technology and application of phytoremediation in soil contaminated by heavy metals. Keywords:Heavy metal; Soil pollution; Hyperaccumulator; Phytoremediation technology