Supporting Information for
Comparison of metals extractability from Al/Fe-based drinking water treatment residuals
Changhui Wang1,a, Leilei Bai1, Yuansheng Pei1*, Laura A. Wendling2
1
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment,
Beijing Normal University, Beijing 100875, P. R. China.
2
The School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD 4072,
Australia.
*
Corresponding Author: Tel/fax: 86-10-5880 1830; E-mail address: yspei@bnu.edu.cn.
a
Present address: State Key Laboratory of Lake Science and Environment, Nanjing Institute of
Geography and Limnology, Chinese Academy of Sciences, Nanjing, China.
1
BJ-WTRs
Intensity
BT-WTRs
GZ1-WTRs
GZ2-WTRs
HZ-WTRs
LZ-WTRs
30
60
o
Position ( 2)
Fig. S1. X-ray diffraction (XRD) spectra of WTRs.
2
Fig. S2. Scanning electron microscopy (SEM) images of WTRs.
3
60
BJ
BT
GZ1
GZ2
HZ
LZ
50
40
Cf
30
20
10
A
l
Fe
A
s
Ba
Be
C
d
C
o
C
r
C
u
K
M
Mg
n
M
o
N
a
N
i
Pb
Sr
V
Zn
0
Metals
Fig. S3 The calculated metals communication factors (Cf) of WTRs. Barium, Mn and Sr within
BJ-WTRs had no non-extractable fractions; therefore, the Cf of Ba, Mn and Sr for BJ-WTRs was not
calculated herein.
4
Table S1 The surface elemental composition of WTRs determined by X-ray photoelectron
spectroscopy (XPS)..
BJ-WTRs
(%)
C
42
O
35
N
2.5
Cl
0.37
S
0.78
Si
7.7
Al
9.1
Fe
0.86
Ca
1.1
Mg
0.26
Na
ND
a
not detected.
Elements
BT-WTRs
(%)
20
48
1.0
NDa
ND
18
8.1
0.84
2.8
1.4
0.33
GZ1-WTRs
(%)
18
49
1.2
0.58
ND
17
12
0.85
0.65
0.38
0.35
GZ2-WTRs
(%)
19
49
1.1
ND
ND
15
13
0.82
0.81
0.35
0.21
5
HZ-WTRs
(%)
29
44
1.2
ND
ND
13
12
0.45
0.75
0.48
ND
LZ-WTRs
(%)
19
48
1.4
ND
ND
17
11
0.63
1.9
0.97
ND
Table S2 Selected properties of WTRs.
Properties
pH
TOM (mg kg-1)
HA (mg kg-1)
FA (mg kg-1)
HM (mg kg-1)
TN (mg kg-1)
TP (mg kg-1)
Alox (mg kg-1)
Feox (mg kg-1)
SSA (m2 g-1)
BJ-WTRs
7.3
107000
2000
15000
90000
12000
1400
62000
82000
61
BT-WTRs
8.5
1400
520
130
710
340
670
800
3200
9.3
GZ1-WTRs
7.9
31000
1300
3300
27000
2300
2800
14000
12000
30
6
GZ2-WTRs
7.7
23000
1300
1300
21000
2000
490
42000
28000
90
HZ-WTRs
7.4
50000
5300
7900
36000
4400
2800
70000
8900
52
LZ-WTRs
7.9
17000
1300
2600
13000
1300
950
18000
5700
34
Table S3 The calculated risk assessment code of metals within the WTRs examined herein.
BJWTRs
Al
Ma
Fe
N
As
L
Ba
VHd
Be
M
Ca
VH
Cd
L
Co
L
Cr
L
Cu
L
K
L
Mg
VH
Mn
M
Mo
N
Na
VH
Ni
M
Pb
N
Sr
VH
V
N
Zn
H
a
represents medium risk;
Elements
b
represents low risk;
c
represents no risk;
d
represents very high risk;
e
represents high risk.
GZ1WTRs
Lb
N
L
He
M
VH
H
H
L
M
L
M
VH
N
M
M
L
H
N
H
GZ2WTRs
M
N
M
H
M
VH
M
M
L
L
L
VH
VH
N
H
M
L
VH
N
M
HZWTRs
L
N
L
VH
M
VH
H
L
L
L
L
L
VH
N
H
L
L
VH
N
M
7
LZWTRs
Nc
N
L
H
L
VH
H
L
L
L
L
M
H
N
M
L
L
VH
N
L
BTWTRs
N
N
L
H
L
VH
H
L
N
L
L
M
H
N
M
L
L
VH
N
L
Table S4 Results of Pearson correlation analyses between the results of bioaccessible extraction and
fractionation for each metal in the WTRs.
Elements
Bioaccessibility
Aa
0.91*
b
Al
A+R
0.90*
A+R+Oc
0.95**
A
0.37
Fe
A+R
0.82*
A+R+O
0.95*
A
0.97**
As
A+R
0.93**
A+R+O
0.21
A
0.92**
Ba
A+R
0.96**
A+R+O
0.93**
A
0.81
Be
A+R
0.82*
A+R+O
0.96**
A
-0.55
Ca
A+R
-0.48
A+R+O
-0.51
A
0.81
Cd
A+R
0.75
A+R+O
0.047
A
0.73
Co
A+R
0.73
A+R+O
0.83*
A
0.86*
Cr
A+R
0.84*
A+R+O
0.86*
A
0.91*
Cu
A+R
0.89*
A+R+O
0.80
a
represents acid-soluble metal;
Elements
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
A
A+R
A+R+O
K
Mg
Mn
Mo
Na
Ni
Pb
Sr
V
Zn
Bioaccessibility
0.81
0.78
0.76
0.98**
0.98**
0.98**
0.98**
0.20
0.23
NCd
NC
-0.049
0.72
0.80
0.86*
0.96*
0.90*
0.93*
0.94*
0.80
-0.56
0.96**
0.95**
0.88*
NC
0.46
0.25
0.39
0.50
0.49
b
represents the sum of acid-soluble metal and reducible metal;
c
represents the sum of acid-soluble metal, reducible metal and oxidizable metal;
d
not calculated;
* significant correlation was found at P < 0.05;
** significant correlation was found at P < 0.01.
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Table S5 Results of Pearson correlation analyses between the results of fractionation and TCLP
anylysis for each metal in the WTRs.
Correlation
coefficient
Al
-0.71
Fe
-0.75
As
0.42
Ba
-0.60
Be
-0.96*
Ca
-0.79
Cd
0.53
Co
0.083
Cr
-0.60
Cu
-0.077
a
not calculated;
Elements
Correlation
coefficient
0.81
0.88*
0.43
NCa
-0.20
0.16
0.59
NC
-0.40
Elements
K
Mg
Mn
Mo
Ni
Pb
Sr
V
Zn
* significant correlation at P < 0.05.
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Table S6 Regulatory limits for metals in biosolids based on guidelines from China, the EU, the
Netherlands and the USA.
USAc (mg kg-1)
Ceiling concentration
Pollutant concentration limit
75
41
2.
85
39
600
4300
1200
600
3000
1500
200
840
300
2.0
57
17
75
200
100
30
420
420
100
36
3000
1500
300
7500
2800
a
refers to Ministry of Environmental Protection of the People’s Republic of China (2009);
Contaminates
As
Cd
Cr
Cu
Pb
Hg
Mo
Ni
Se
Zn
Chinaa
(mg kg-1)
75
15
1000
1500
1000
15
EU limitb
(mg kg-1)
b
refers to Iranpour (2004);
c
refers to USEPA (1995).
Netherlands limitb
(mg kg-1)
15
1.25
75
75
100
0.75
In comparison to the Chinese regulatory guidelines for land application of sewage sludge, the
respective total contents of As (11-56 mg kg-1), Cd (0.30-1.3 mg kg-1), Cr (29-89 mg kg-1), Cu (22-140
mg kg-1), Hg (not detected), Ni (15-75 mg kg-1), Pb (10-200 mg kg-1) and Zn (60-410 mg kg-1) in the
WTRs (Table 1) were less than the maximum guideline levels (Ministry of Environmental Protection of
the People’s Republic of China, 2009). Total quantities of all metals within the WTRs were also within
regulatory guidelines in the EU and less than US ceiling (maximum) concentration limits (USEPA 1995;
Iranpour et al. 2004). In addition to maximum (ceiling) concentrations, the US regulatory guidelines for
land application of sewage sludge also give pollutant concentration limits. If one or more of these
concentration limits are not met but the concentration is less than the ceiling concentration, the total
quantity of sewage sludge for land application is restricted. In comparison to these US pollutant
concentration limits, only As in BJ-WTRs (56 mg kg-1) was greater than the pollutant concentration
limit (41 mg kg-1; USEPA 1995). In addition, according to the regulatory guidelines in New Zealand,
the total As and Cd content of BJ-WTRs, total As in BT-WTRs, total As, Cr, Cu and Ni in GZ1-WTRs,
total Pb in GZ2-WTRs, total As and Zn in HZ-WTRs and the total As and Ni contents of LZ-WTRs
were greater than the regulatory limits (Iranpour et al. 2004).
Therefore, land application of the WTRs investigated in the present study could be allowed in
China and the EU, and with the exception of the BJ-WTRs which would be subject to application limits
based on their As content, land application of other WTRs investigated would not be restricted in the
USA. In contrast, none of the WTRs would be suitable for land application in New Zealand.
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References
Iranpour R, Cox HHJ, Kearney RJ, Cleark JH, Pincince AB, Daigger GT (2004) Regulations for
biosolids land application in U.S. and European Union. J Residuals Sci Tech 1:209-222.
Ministry of Environmental Protection of the People’s Republic of China (2009) GJ/T 309-2009:
Disposal of sludge from municipal wastewater treatment plant — Control standards for
agricultural use. China Environmental Science Press, Beijing.
USEPA (1995) A Guide to the biosolids risk assessments for the EPA part 503 rule.
EPA-832-B-93-005. U.S. Environmental Protection Agency, Washington, D.C.
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