93

5

Chemical Remediation Techniques for the Soils

Contaminated with Cadmium and Lead in Taiwan

Zueng-Sang Chen, Geng-Jauh Lee, and Jen-Chyi Liu
CONTENTS

5.1 Introduction 93
5.2 Materials and Methods 94
5.2.1 The Contaminated Sites 94
5.2.2 Analysis of Basic Soil Properties 95
5.2.3 Treatments in Pot Experiments 95
5.2.4 Bioavailability to Wheat 96
5.2.5 Sequential Fractionation of Heavy Metals in Soils 96
5.2.6 Statistical Analyses 96
5.3 Results and Discussion 96
5.3.1 Cd and Pb Concentration Extracted by Different Reagents in
Untreated Soils 96
5.3.2 Changes on the Bioavailability of Cd and Pb after Chemical Treatments 97
5.3.3 Transformation of Chemical Forms of Cd and Pb in the Amended Soils 98
5.3.4 Effect of Chemical Treatments on the Concentration of Cd and
Pb Uptake by Wheat 102
5.4 Conclusions 102
Acknowledgments 103
References 103


efficient and save time for changing the land uses of contaminated sites (Chen et al., 1994).
The most effective remediation techniques of the engineering method are removing the
polluted surface soils and replacing them with uncontaminated soil. Then, the removed
contaminated soils can be washed with some chemical extractants or chelating reagents
(Chen et al., 1994). The remediation techniques of chemical treatments include adding
some chemical material into the polluted soils to reduce the concentration of Cd and Pb in
the soil solution, such as lime material, manure or composts, phosphate materials, and
hydrous iron and manganese oxides (Mench et al., 1995; Chen and Lee, 1997; Chen et al.
1997). The application of lime materials can significantly reduce the solubility of heavy
metals in contaminated sites (McBride and Blasiak, 1979; McBride, 1980; Sommers and
Lindsay, 1979; Kuo et al., 1985; Liu et al., 1998). Some reports also indicated that the appli-
cation of hydrous iron or manganese oxides in contaminated soils could reduce the concen-
tration of Cd or Pb in the soil solution (McKenzie, 1980; Kuo and McNeal, 1984; Tiller et al.,
1984; Khattak and Page, 1992; Mench et al., 1994). High quantity applications of phosphate
in polluted soils also can reduce the solubility of zinc in the soil solution by precipitation
(Bolland et al., 1977; Saeed and Fox, 1979; Barrow, 1987). Some vegetation species, flowers,
and trees planted in the polluted soils are also effective in removing the heavy metals from
the sites (Lee and Liao, 1993; Lee and Chen, 1994).
The objectives of this chapter are (1) to evaluate the effects of different chemical remedi-
ation treatments on the reduction of Cd and Pb soluble in the soils, and (2) to evaluate their
bioavailability for wheat grown in the contaminated soils.

5.2 Materials and Methods

5.2.1 The Contaminated Sites

Two rural soils, Chunghsing clayey soil (including sites A and B) and Chaouta sandy soil
(including sites C and D), were selected from contaminated sites irrigated with discharged
water from chemical plants in northern Taiwan (Chen, 1991). The total area of contami-
nated sites in these two regions is about 100 ha.

Cd and Pb. The bioavailability concentrations of Cd and Pb in polluted soils were deter-
mined by different extraction solutions, such as distilled water by shaking 2 h, 0.1

M

HCl
by shaking 1 h (EPA/ROC, 1991), 0.005

M

DTPA (pH 5.3) by shaking 1 h (Norvell, 1984),
and 0.05

M

EDTA (pH 7.0) by shaking 1 h (Mench et al., 1994). Then the extraction solution
was filtered with Whatman no. 42 filter paper and 0.45

µ

m Millipore filter paper. The con-
centrations of Cd and Pb in the extraction solution were determined by flame atomic
absorption spectroscopy (Hitachi 180-30 type). Total concentration analysis of Cd and Pb in
the polluted soil was digested with concentrated HCl and HNO

3

(3:1, v/v) and filtered with
Whatman no. 42 filter paper and 0.45



pH
O.C. Sand Silt Clay

CEC Exch. Base
Site Soils H

2

O KCl (g/kg) (g/kg) (cmol(+)/kg soil) (%)

Chungfu A 5.0 4.3 23.5 113 481 406 12.4 3.82 31
B 5.5 4.5 15.2 102 524 374 9.9 3.77 38
Tatan C 5.5 4.7 12.1 726 57 217 4.5 3.23 72
D 5.4 4.8 12.9 742 123 135 4.5 3.71 82

From Lee, G. J., The Assessment of Remediation Techniques by Chemical Treatments for Soils Contaminated
with Cadmium and Lead, Master’s thesis, Graduate Institute of Agricultural Chemistry, National Taiwan
University, Taipei, 1996. With permission.

4131/frame/C05 Page 95 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC

96

Environmental Restoration of Metals–Contaminated Soils

5.2.4 Bioavailability to Wheat

Several extractants were used to extract the concentration of heavy metals for prediction of

The extraction solution was filtered by Whatman no. 42 filter. The concentration of Cd and
Pb was determined by the atomic adsorption spectrophotometer (Hitachi 180–30 type).
The harvested samples of wheat were dried at 60°C for 2 days and digested with concen-
trated sulfuric acid mixed with perchloric acid. The concentration of Cd and Pb in the
digestion solution was determined by atomic adsorption spectrophotometer.

5.2.5 Sequential Fractionation of Heavy Metals in Soils

To evaluate chemical forms of heavy metals in treated contaminated soils, a sequential
extraction technique based on the method of Mench et al. (1994) was used. Briefly, the
sequential fraction procedure was performed in four steps with the assumption that the
four chemical forms of metals existing in the contaminated soils were (1) water soluble,
exchangeable, weakly bounded to organic matter, carbonate fractions, extracted with
0.11

M

acetic acid (HOAC) and shaken for 16 h; (2) occluded Fe or Mn oxide fraction,
extracted with 0.1

M

hydroxyl ammonium chloride (HONH

3

Cl) and shaken for 16 h;
(3) organically bound and sulfide fraction, extracted with 1

M

5.3.1 Cd and Pb Concentration Extracted by Different Reagents in Untreated Soils

The concentrations of Cd and Pb in these four contaminated soils extracted with different
extraction reagents are shown in Table 5.2. Results indicated that the most serious contam-
inated site was site D with sandy soils showing the highest concentration of Cd (18.6
mg/kg) and Pb (611 mg/kg) (Table 5.2). For the clayey soils, site A is a more seriously pol-
luted site (5.47 mg/kg total Cd and 39.2 mg/kg total Pb) than site B.

4131/frame/C05 Page 96 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC

Chemical Remediation Techniques for the Soils Contaminated with Cadmium and Lead

97

5.3.2 Changes on the Bioavailability of Cd and Pb after Chemical Treatments

An index of the bioavailability of heavy metals in these polluted soils can be evaluated by
different extractants, such as distilled water, 0.1

M

Ca(NO

3

)

2


in these polluted soils consists of manganese oxide, calcium carbonate, or zeolite based on
the concentration extracted by Ca(NO

3

)

2

or HOAC (

p

<0.10), and there are no effects for the
other chemical treatments (Table 5.4). These results support the results that the application
of lime materials can significantly reduce the solubility of Pb in the soil solutions of contam-
inated sites (McBride and Blasiak, 1979; McBride, 1980; Sommers and Lindsay, 1979; Kuo et
al., 1985; Mench et al., 1994; Lee, 1996). These results also support results that the application
of hydrous iron or manganese oxide materials can significantly reduce the solubility of Pb
in the soil solutions (McKenzie, 1980; Kuo and McNeal, 1984; Tiller et al., 1984; Khattak and
Page, 1992; Mench et al., 1994; Lee, 1996). These results also support results that the appli-
cation of zeolite can significantly reduce the solubility of Pb in the soil solutions
(Gworek, 1992). In this study of Taiwan polluted soils, application of hydrous manganese

TABLE 5.2

Cd and Pb Concentration in Soils Extracted by Different Single Solutions for Four Contaminated

Soils before Chemical Treatments


From Lee, G. J., The Assessment of Remediation Techniques by Chemical Treatments for Soils Contaminated
with Cadmium and Lead, Master’s thesis, Graduate Institute of Agricultural Chemistry, National Taiwan Uni-
versity, Taipei, 1996. With permission.

4131/frame/C05 Page 97 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC

98

Environmental Restoration of Metals–Contaminated Soils

oxides is also another key factor to control the extractability (or bioavailability) of Pb in
clayey or sandy polluted soils.

5.3.3 Transformation of Chemical Forms of Cd and Pb in the Amended Soils

The changes of sequential fractions of Cd and Pb in soils B and D after chemical treatments in
2 months are shown in Figure 5.1 and 5.2 (the results of site A and site C are not shown here).

TABLE 5.3

Cadmium Concentrations Extracted by Single Extractant for Four Soils Treated with Different

Chemical Materials

Cd Concentrations in Single Extraction Solution
Treatment Water Ca(NO

3


Control ND 4.36 a 4.48 a 4.46 a 4.77 a
FO ND 4.31 a 4.21 a 4.06 ab 4.66 a
MO ND 4.41 a 4.42 a 3.66 b 4.42 b
Lime ND 4.26 a 3.34 c 4.26 a 4.45 b
Phosphate ND 4.26 a 4.21 a 3.66 b 4.66 a
Compost ND 4.16 a 3.77 b 3.66 b 4.45.b
Zeolite ND 4.21 a 3.55 bc 3.66 b 4.23 c

Site D after 2 Months

Control 0.12 a 13.7 a 15.1 a 17.0 a 15.3 a
FO 0.12 a 13.7 a 15.1 a 16.0 bc 15.3 a
MO 0.12 a 13.7 a 14.0 ab 15.3 c 15.8 a
Lime ND b 13.7 a 11.3 c 16.2 c 15.8 a
Phosphate ND b 13.2 a 14.0 ab 16.2 bc 15.8 a
Compost ND b 13.2 a 12.4 bc 14.9 c 15.3 a
Zeolite ND b 13.7 a 12.9 bc 17.0 ab 15.8 a

Note:

Data are expressed as mean value and with the same letter within a column (

p

<0.10) are not significantly
different. FO: iron oxides; MO: manganese oxides; ND: not detectable.
From Lee, G. J., The Assessment of Remediation Techniques by Chemical Treatments for Soils Contaminated
with Cadmium and Lead, Master’s thesis, Graduate Institute of Agricultural Chemistry, National Taiwan Uni-
versity, Taipei, 1996. With permission.


)

2

EDTA HOAC HCl

(mg/kg)

Site A after 2 Months

Control ND 14.6 a 12.2 a 1.27 a 11.3 a
FO ND 12.9 b 10.5 ab 1.27 a 11.3 a
MO ND 8.59 c 6.13 c 1.27 a 6.14 b
Lime ND 12.9 b 11.3 ab 1.27 a 10.5 a
Phosphate ND 13.3 ab 12.2 a 1.27 a 11.3 a
Compost ND 14.2 ab 10.5 ab 1.27 a 11.3 a
Zeolite ND 12.9 b 8.72 b 1.27 a 10.5 a

Site B after 2 Months

Control ND 8.13 a 7.,84 a 1.26 a 7.84 a
FO ND 6.42 ab 6.11 b 1.26 a 6.12 b
MO ND 4.29 c 3.53 c 1.26 a 4.39 c
Lime ND 6.42 ab 7.84 a 1.26 a 6.12 b
Phosphate ND 6.42 ab 7.84 a 1.26 a 6.12 b
Compost ND 7.28 ab 6.97 ab 1.26 a 6.12 b
Zeolite ND 5.57 bc 4.39 c 1.26 a 5.25 bc

Site C after 2 Months



4131/frame/C05 Page 99 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC

100

Environmental Restoration of Metals–Contaminated Soils

FIGURE 5.1

The distribution of Cd in different soil fractions in soil B treated in 1 month (a) and in 2 months (b).
a.
b.
Fraction (%)
100
80
60
40
20
0
Control Fe
Oxides
Mn
Oxides
Lime Compost ZeolitePO
4
Treatments
100
80
60

40
20
0
Control Fe
Oxides
Mn
Oxides
Lime Compost ZeolitePO
4
Treatments
Residual Fraction
Organically Bound and Sulphide Fraction
Fe- and Mn-Bounded Form
Exchangeable, Organic Matter Weakly Bounded and Carbonate Form

4131/frame/C05 Page 101 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC

102

Environmental Restoration of Metals–Contaminated Soils

5.3.4 Effect of Chemical Treatments on the Concentration of Cd and Pb Uptake
by Wheat

The concentration and total uptake of Cd and Pb in wheat species (

Triticum aestivum

) grow-

Cd

Control 45.0 a 32.7 a 95.5 a 115 a
FO 35.5 ab 35.5 a 80.5 a 115 a
MO 21.8 bc 13.6 b 61.4 b 101 ab
Lime 15.5 c 5.45 b 20.5 c 99.6 ab
Phosphate 34.1 ab 13.6 b 84.6 a 108 ab
Compost 34.1 ab 8.20 b 56.0 b 115 a
Zeolite 28.7 b 4.68 b 24.6 c 69.6 b

Pb

Control 108 a 65.3 a 43.5 ab 305 a
FO 43.5 b 43.5 ab 43.5 ab 218 ab
MO 43.5 b 43.5 ab 21.8 b 196 b
Lime 43.5 b 21.8 b 21.8 b 152 b
Phosphate 21.8 b 21.8 b 43.5 ab 196 b
Compost 21.8 b 21.8 b 21.8 b 174 b
Zeolite 21.8 b 21.8 b 65.3 a 152 b

Note:

Data are expressed as mean value and with the same letter within a column (

p

<0.10) are not significantly
different. FO: iron oxides; MO: manganese oxides.
From Lee, G. J., The Assessment of Remediation Techniques by Chemical Treatments for Soils Contaminated
with Cadmium and Lead, Master’s thesis, Graduate Institute of Agricultural Chemistry, National Taiwan Uni-

, 38, 453, 1987.
Bolland, M.D.A., A.M. Posner, and J.P. Quirk, Zinc adsorption by geothite in the absence and
presence of phosphate,

Aust. J. Soil Res.

, 15, 179, 1977.
Chen, Z.S., Cadmium and lead contamination of soils near plastic stabilizing materials producing
plants in northern Taiwan,

Water, Air, & Soil Pollut.

, 57, 745, 1991.
Chen, Z.S., Soil properties of soil contaminated with Cd and Pb and their remediation tests in Taiwan,
in

Proc. Remediation of Polluted Soils and Sustainable Land Use

, Taipei, Taiwan, 1994, 3-1.
Chen, Z.S. and D.Y. Lee, Evaluation of remediation techniques on two cadmium polluted soils in
Taiwan, in

Remediation of Soils Contaminated with Metals

. Special Volume of 2nd Int. Conf. on
the Biogeochemistry of Trace Elements, Taipei, Taiwan, September 5–10, 1993, I.K. Iskandar and
D.C. Adriano, Eds.,

Science Reviews


Note:

Data are expressed as mean value and the mean value with the same letter within a column (

p

<0.10) are
not significantly different. FO: iron oxides; MO: manganese oxides.
From Lee, G. J., The Assessment of Remediation Techniques by Chemical Treatments for Soils Contaminated
with Cadmium and Lead, Master’s thesis, Graduate Institute of Agricultural Chemistry, National Taiwan Uni-
versity, Taipei, 1996. With permission.

4131/frame/C05 Page 103 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC

104

Environmental Restoration of Metals–Contaminated Soils

Chen, Z.S., D.Y. Lee, D.N. Huang, and Y.P. Wang, The effect of chemical methods treated in polluted
soils on the Cd uptake by the vegetables, in

Proc. 3rd Workshops of Soil Pollution and Prevention

,
Taipei, Taiwan (in Chinese, English abstract and tables), 1992a, 277.
Chen, Z.S., D.Y. Lee, T.K. Lin, and Y.P. Wang, Selecting the suitable vegetation growing in the soils
contaminated with Cd in northern Taiwan, in

Proc. 3rd Workshops of Soil Pollution and Prevention

Gee, G.W. and J.W. Bauder, Particle-size analysis, in Methods of Soil Analysis, Part 1. Physical and
Mineralogical Methods, 2nd ed., Klute, A. et al., Eds., Agronomy Monograph 9, 383, 1986.
Gworek, B., Lead inactivation in soils by zeolites, Plant Soil, 143, 71, 1992.
Impents, R., J. Fagot, and C. Avril, Gestion des sols contaminé par les métaux lourds. Association
Francaise Interprofessionnelle du Cadmium, Paris, France, 1991.
Jackson, A.P. and B.J. Alloway, The transfer of cadmium from agricultural soils to the human food
chain, in Biogeochemistry of Trace Metals, D.C. Adriano, Ed., Lewis Publishers, Boca Raton, FL,
1992, 109.
Khattak, R.A. and A.L. Page, Mechanism of manganese adsorption on soil constituents, in
Biogeochemistry of Trace Metals, D.C. Adriano, Ed., Lewis Publishers, Boca Raton, FL, 1992, 383.
Kuo, S. and B.L. McNeal, Effects of pH and phosphate on cadmium sorption by a hydrous ferric
oxide, Soil Sci. Soc. Am. J., 48, 1040, 1984.
Kuo, S., E.J. Jellum, and A.S. Baker, Effects of soil type, liming, and sludge application on Zn and
Cd availability to swiss chard, Soil Sci., 139, 122, 1985.
Lakanen, E. and R. Ervio, A comparison of eight extractants for the determination of plant available
micronutrients in soils, Acta Agral. Fenn., 123, 223, 1971.
Lee, D.Y. and Z.S. Chen, Plants for cadmium polluted soils in northern Taiwan, in Biogeochemistry
of Trace Elements, Special issue of Environmental Geochemistry and Health, D.C. Adriano, Z.S. Chen,
and S.S. Yang, Eds., Sci. Technol. Lett., 16, 161, 1994.
Lee, F.Y. and C.T. Liao, Removal of Cd and Cu from the polluted soils by vegetations, in Proc. 4th
Workshop on Soil Protection and Remediation, Taipei, Taiwan (in Chinese, English abstract and
tables), 1993, 471.
Lee, G.J., The Assessment of Remediation Techniques by Chemical Treatments for Soils Contami-
nated with Cadmium and Lead, Master’s thesis, Graduate Institute of Agricultural Chemistry,
National Taiwan University, Taipei (in Chinese, English abstract and tables), 1996.
Liu, J.C., K.S. Looi, Z.S. Chen, and D.Y. Lee, The effects of composts and calcium carbonate on the
uptake of cadmium and lead by vegetables grown in polluted soils, J. Chinese Inst. Environ.
Eng., 8, in press.
Lu, S.T., H.L. Chang, C.C. Houng, and K.C. Yee, Cadmium and Lead in the Discharged Water,
Sediments, and Brown Rice of Polluted Region, Project report of Environmental Protection

Saeed, M. and R.L. Fox, Influence of phosphate fertilization on zinc adsorption by tropical soils,
Soil Sci. Soc. Am. J., 43, 683, 1979.
SAS Institute, SAS User’s Guide, Statistics, SAS Inst., Cary, NC, 1982.
Sommers, L.E. and W.L. Lindsay, Effect of pH and redox on predicted heavy metal-chelate equilibria
in soils, Soil Sci. Soc. Am. J., 43, 39, 1979.
Thomas, G.W., Exchangeable cations, in Methods of Soil Analysis, Part 2, Chemical and Microbiological
Properties, 2nd ed., A.L. Page et al., Eds., Agronomy Monograph 9, 149, 1982.
Tiller, K.G., J. Gerth, and G.W. Bruemmer, The relative affinities of Cd, Ni, and Zn for different clay
fraction and goethite, Geoderma, 34, 17, 1984.
Wang, Y.P., K.C. Li, Z.S. Chen, Y.M. Huang, and C.L. Liu, Assessment of Soil Pollution and Soil Reme-
diation Techniques Tested in the Polluted Soils, Project paper of EPA/ROC (EPA-83-H105-09-04),
Taipei, Taiwan (in Chinese, English abstract and tables), 1994.
Wang, Y.P., M.C. Wang, and Z.S. Chen, The Soil Remediation Studies in Soils Contaminated with
Cd and Pb, Project paper of EPA/ROC (EPA-78-004-09-109), Taipei, Taiwan (in Chinese, English
abstract and tables), 1989.
4131/frame/C05 Page 105 Friday, July 21, 2000 4:56 PM
© 2001 by CRC Press LLC