Stability of diethyl dithiocarbamate chelates with Cu(II), Zn(II) and Mn(II)

Article abstract of DOI:10.1016/j.molstruc.2019.02.009

Immobilization has been regarded as one of the most effective technology to eliminate heavy metals contamination. However, the stability of immobilization products and the leakage of immobilized heavy metals impeded its further application. In order to depict the stability of chelating complexes C₁₀H₂₀MnN₂S₄, C₁₀H₂₀CuN₂S₄ and C₁₀H₂₀ZnN₂S₄, DSC-TG analysis, DFT calculation and leakage tests were carried out to reveal the stabilities and the potential leakage risks of immobilized heavy metals when sodium diethyl dithiocarbamate was used as soil amendments. The results indicated that the stability of these three chelating complexes was ranked in the order of C₁₀H₂₀CuN₂S₄> C₁₀H₂₀ZnN₂S₄> C₁₀H₂₀MnN₂S₄. Such precipitations as C₁₀H₂₀MnN₂S₄, C₁₀H₂₀CuN₂S₄ and C₁₀H₂₀ZnN₂S₄ were stable under the neutral and alkaline environment. Meanwhile, leakage of immobilized heavy metals decreased with the increasing leaching pH, whereas time and temperature had no significant impact on the leakage of immobilized heavy metals. And the maximum leakage of immobilized heavy metals was lower than the limited concentration.

Full text of DOI:10.1016/j.molstruc.2019.02.009

Accepted Manuscript
Stability of diethyl dithiocarbamate chelates with Cu(II), Zn(II) and Mn(II)
Wengang Liu, Hao Duan, Dezhou Wei, Baoyu Cui, Xinyang Wang
PII:
S0022-2860(19)30133-4
10.1016/j.molstruc.2019.02.009
MOLSTR 26166
DOI:
Reference:
To appear in:
Journal of Molecular Structure
Received Date:
Accepted Date:
21 September 2018
04 February 2019
Please cite this article as: Wengang Liu, Hao Duan, Dezhou Wei, Baoyu Cui, Xinyang Wang,
Stability of diethyl dithiocarbamate chelates with Cu(II), Zn(II) and Mn(II), Journal of Molecular
Structure (2019), doi: 10.1016/j.molstruc.2019.02.009
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
our customers we are providing this early version of the manuscript. The manuscript will undergo
copyediting, typesetting, and review of the resulting proof before it is published in its final form.
Please note that during the production process errors may be discovered which could affect the
content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT
1
2
3
4
5
Stability of diethyl dithiocarbamate chelates with Cu(II), Zn(II) and Mn(II)
Wengang Liu*, Hao Duan, Dezhou Wei, Baoyu Cui, Xinyang Wang
School of Resources and Civil Engineering, Northeastern University, Shenyang, Liaoning
110819, China
Corresponding author: E-mail addresses: liuwengang@mail.neu.edu.cn
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
Abstract
Immobilization has been regarded as one of the most effective technology to eliminate heavy
metals contamination. However, the stability of immobilization products and the leakage of
immobilized heavy metals impeded its further application. In order to depict the stability of
chelating complexes C H MnN S , C H CuN S and C H ZnN S , DSC-TG analysis, DFT
1
1
1
1
1
1
1
1
1
1
2
1
0
20
2
4
10 20
2
4
10 20
2 4
calculation and leakage tests were carried out to reveal the stabilities and the potential leakage
risks of immobilized heavy metals when sodium diethyl dithiocarbamate was used as soil
amendments. The results indicated that the stability of these three chelating complexes was ranked
in the order of C H CuN S > C H ZnN S > C H MnN S . Such precipitations as
1
0
20
2
4
10 20
2
4
10 20
2 4
C H MnN S , C H CuN S and C H ZnN S were stable under the neutral and alkaline
1
0
20
2
4
10 20
2
4
10 20
2 4
environment. Meanwhile, leakage of immobilized heavy metals decreased with the increasing
leaching pH, whereas time and temperature had no significant impact on the leakage of
immobilized heavy metals. And the maximum leakage of immobilized heavy metals was lower
than the limited concentration.
Key words: Stability; Diethyl dithiocarbamate; Immobilization; DFT; Metal leakage
1

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
1 Introduction
Heavy metals are directly or indirectly discharged into the environment with the
rapid development industrials such as metal plating facilities, mining processing,
metallurgy, leather, battery manufacture, medicine, etc [1-3]. Unlike organic wastes,
heavy metals are non-biodegradable and they can accumulate in living tissues through
food chain. Besides, they can cause serious health diseases or disorders to human
once the accumulated heavy metals exceeded the limited concentration [4, 5]. Thus,
heavy metals contamination has drawn more and more attention around the world [6,
7]. Up to now, various methods such as chemical precipitation [8, 9], ion exchange
[10, 11], adsorption [12, 13], ultrafiltration [14], electrochemical [15],
coagulation-flocculation [16] and immobilization/stabilization [17] have been
developed to eliminate heavy metals contamination. Among these methods,
immobilization/stabilization has been identified by the U.S. EPA as the best
technology available for 57 types of waste [18]. Chelating agents, which have high
removal rate on heavy metals in a broad pH use range, have been widely used to
immobilize/stabilize heavy metals through adsorption, precipitation and complexation
reactions [19, 20].
−
Dithiocarbamates (R CNS ) are a versatile class of monoanionic 1,1-dithio
2
2
ligands and they have the strong tendency to share electrons between nitrogen and
sulfur with heavy metals to form ring chelates[5, 21, 22]. Thus, dithiocarbamate
derivatives were extensively used to treat heavy metals pollution. Hou et al. [22]
2

ACCEPTED MANUSCRIPT
2
+
2+
2+
2+
2+
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
6
6
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
investigated the interference of four metal ions (Cu , Ni , Pb , and Zn ) on Hg
precipitation efficiency during the reaction of Hg2+ with DTCR
-
+
2+
([CH NCSS CH Na ] ). The results indicated that DTCR can stabilize Hg very well.
2
2
n
Halawa et al.[23] prepared two types of dithiocarbamate ligands, aliphatic
(diethyldithiocarbamate) and aromatic (diphenyldithiocarbamate) to remove Pb, Cd,
Cu and Zn from polluted water. The results demonstrated that the
diphenyldithiocarbamate was more effective to remove the selected heavy metal ions
from aqueous than activated carbon. Liu et al.[24] synthesized a novel Zn(II)
dithiocarbamate/ZnS nanocomposite, which exhibited outstanding performance on
6
+
removal of Cr from aqueous solutions by a simple one-step method. And the results
6
+
indicated that this nanocomposite is an effective amendment for Cr and the removal
rate could reach more than 98% in just a few seconds.
Sodium diethyldithiocarbamate (DDTCNa) is much cheaper and accessible than
other dithiocarbamate derivatives compounds, which has strong chelating abilities
towards some heavy metals and has been used to eliminate heavy metals
contamination. Liu et al. [20] investigated the immobilization of Cu(II) and Zn(II)
from contaminated soil by using sodium diethyldithiocarbamate and Na S. The results
2
revealed that DDTCNa showed better immobilization effect to Cu(II) and Zn(II) than
Na S at neutral pH. During the immobilization process, the stability of products is an
2
important issue because the unstable compounds would cause secondary pollution
[25]. However, there is little research about the stability of DDTC-metal chelating
3

ACCEPTED MANUSCRIPT
6
6
6
6
6
6
6
7
7
7
7
7
7
7
7
7
7
8
8
8
8
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
complexes which inhibited its further application [26]. Thus, in this paper，DSC-TG
analysis, DFT calculation and leakage tests were carried out to depict the stability of
DDTC-metal chelating complexes. The purpose of this paper is to evaluate the
stabilities of such chelating complexes as C H MnN S , C H CuN S and
1
0
20
2
4
10 20
2 4
C H ZnN S . And the potential leakage risks of immobilized heavy metals when
1
0
20
2 4
DDTCNa was used as soil amendments were also revealed.
2 Experimental
2.1 Chemicals
The chemical pure DDTCNa was purchased from Sinopharm Chemical Reagent
Co., Ltd and used as chelating agent. CuSO 5H O, ZnSO 7H O and MnSO H O of
4
2
4
2
4
2
analytical grade were purchased from Xilong Scientific Co., Ltd. The pH was
adjusted using HCl and NaOH, which were purchased from Tianjin Kermel Reagent
Co., Ltd. All reagents were used as received without any further purification.
Deionized water was used in all experiments.
2.2 Synthesis of chelates and characterization
The chelating complexes were generated by mixing DDTCNa and metal sulfates
together in solution. The DDTCNa (10 mmol) were dissolved in dried beaker with 50
mL deionized water, then the metal sulfates (5 mmol) were added into the beaker. The
mixture were agitated with the magnetic stirring (SH-3A, Beijing Jinbeide Industrial
and Trading Co., Ltd.) at 2000r/min until the formation of precipitation [27, 28]. The
precipitations were filtered under reduced pressure and washed with deionized water
4

ACCEPTED MANUSCRIPT
8
8
8
8
8
8
9
9
9
9
9
9
9
9
9
9
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
for three times before being dried in a vacuum oven at 40°C for 48h. The
crystallographic structure of the precipitations was investigated by glancing angle
X-ray diffractometer (GAXRD) (Shimadzu XRD-6100) with Cu Ka radiation. The
incident angle was 0.5°.
2.3 Thermal Analysis
The thermal behavior of the chelating complexes was analyzed by
thermogravimetry (TG) and differential scanning calorimetry (DSC) using a Netzsch
model STA 449 F3 Jupiter at a heating rate of 10°C/min in argon atmosphere.
2.4 Computational details
∆E was calculated using DFT method. All calculations were performed in DMol3
module in Materials Studio 6.0 (2012). The computation is based on Perdew-Wang
(PWC) functional of Local-density approximations (LDA) [29]. All Electron
Relativistic was chosen for the core treatment and the basic set was double numerical
plus polarization (DNP). For self-consistent electronic minimization, the Pulay
-6
density mixing method was used with a SCF convergence tolerance of 1.0×10 . And
convergence criteria fixed for the energy, maximum force and maximum
-
5
1
1
00
displacement tolerance were 1.0×10 Ha, 0.002 Ha/Å and 0.005Å, respectively [30,
01 31]. The ∆E was calculated based on the following equation [32]:
1
1
02
03
∆E=Eproducts-Ereactants
(1)
Where Eproducts and Ereactants was the energy of optimized products and reactants.
5

ACCEPTED MANUSCRIPT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
04
05
06
07
08
2.5 Leakage tests
0.1g chelating complexes were added into 50mL deionized water, and adjusted
the slurry pH and temperature. And then, the mixture was centrifuged at speed of
3000r/min to remove the undissolved chelates. The concentration of metal ions in
supernatant was measured by ICP (Teledyne Leeman Labs, USA).
09 3 Result and discussion
10
11
12
13
14
15
16
17
18
19
20
21
3.1 Characterization of the precipitations
-
The sulfur atoms of -CSS are likely to share the isolated electron pair with heavy
metal ions to form coordination bond due to their low electro-negativity and large
-
atomic radius [33]. The mechanism of -CSS chelate with heavy metal ions (M
represents Cu, Zn and Mn) had been clarified clearly and shown in Eq.(2) [21]. Fig. 1
showed the XRD patterns of precipitate generated by mixing heavy metal ions with
DDTCNa aqueous. Compared with the standard images, characteristic peaks of
C H MnN S , C H CuN S and C H ZnN S (corresponding JCPDS–ICDD
1
0
20
2
4
10 20
2
4
10 20
2 4
numbers were 19-1634, 44-1765 and 44-1815) were found [34, 35]. This revealed
precipitates of C H MnN S , C H CuN S and C H ZnN S were generated
1
0
20
2
4
10 20
2
4
10 20
2 4
when heavy metal ions reacted with DDTCNa solution, which was in consistence
with the theoretic analysis.
S
C H
2 5
S
S
S
C H
2 5
C H
2
5
M2+
C
N
N
C
M
2
N
C
S
+
C H
2
5
C H
2
C2H5
S
5
1
22
(2)
6

ACCEPTED MANUSCRIPT
1
23
1
24
1
1
25
26
Fig.1 The X-ray diffraction patterns of A, B and C
7

ACCEPTED MANUSCRIPT
1
1
1
27
28
29
3.2 Thermal analysis of the chelate complexes
The DSC-TG curves of the chelating complexes were shown in Fig.2. The initial
mass of A, B and C was 11.156 mg, 14.500 mg and 10.900 mg, respectively.
1
30
1
31
8

ACCEPTED MANUSCRIPT
1
1
32
33
Fig.2 The DSC-TG analysis of A, B and C
1
1
1
1
1
1
1
1
1
1
1
1
1
1
34
35
36
37
38
39
40
41
42
43
44
45
46
47
In this study, thermal behavior of chelating complexes was investigated under
dynamic inert atmosphere. TG curve shows the mass change of material as a function
of time over a temperature range [36]. DSC measures the difference in the amount
heat required to maintain the sample and reference at the same temperature. The DSC
curve shows the amount of heat applied, as a function of temperature or time [37].
According to the DSC curves, an endothermic peak in the temperature range of
190-225°C for A was observed, B exhibited two exothermic peak in the temperature
range of 165-220°C and 270-300°C, in the case of C, the exothermic peak was located
in the temperature range of 170-185°C. Generally speaking, phase transition,
crystallization and melting of a sample usually leads to thermal change with the mass
of sample seldom changed. In this study, the thermal changed accompanied with mass
change of sample, thus, it is reasonable to infer that the thermal changes were caused
by the decomposition of A, B and C. And the onset temperature of decomposition of
A, B and C was 174.8°C, 197.2°C and 195.0°C, respectively. Therefore, the thermo
9

ACCEPTED MANUSCRIPT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
analysis indicated that the thermostabilities of these three chelating complexes were
decreased in the order from B, C to A.
3.3 DFT calculation results
Chelating stability largely depends on covalent radius, metal ion radius, ligand
structure, atomic electronegativity, bonding orbitals, electron configuration, spatial
structure, and other factors. Meanwhile, various theories such as HSAB theory [38],
Crystal field theory [39], Ligand field theory [40], Orbital hybridization [41], Stability
constant [42] have been proposed to determine the stability of different compounds
and explained it well to some extent. However, it is difficult to explain the stability of
chelating complexes by taking only one or two aspects into account [26].
Thankfully, with the development of computation technology, it is possible for
us to simulation the reaction process and understand the structure information in the
perspective of electron, orbital, bond, spatial configuration thoroughly [43]. Thus, in
order to further reveal the stability of these three chelating complexes, DFT
calculation was applied to compare the stability of three chelating complexes. The
configuration and primary parameters of A, B and C were shown in Fig.3 and Table 1.
The spin state of A, B and C was sextet, singlet and doublet, respectively. The
configuration, bond angle and bond length of B and C were similar to the previous
literature [27, 28, 34, 35], to date, the parameters of A were not clearly, and we
calculated it in the same way. As Table 1 shown, the bond angle of S(2)-Cu(1)-S(7)
and S(3)-Cu(1)-S(6) was 179.245º and 179.392º, the bond angle of S(3)-Mn(1)-S(7)
1
0

ACCEPTED MANUSCRIPT
1
1
1
1
1
69
70
71
72
73
and S(2)-Mn(1)-S(6) was 128.708º and 128.429º, the bond angle of S(3)-Zn(1)-S(7)
and S(2)-Zn(1)-S(6) was 128.228º and 128.796º, which suggested the pseudo-planar
structure of the CuS framework and the pseudo-tetrahedral structure of MnS and
4
4
ZnS framework. The corresponding calculation results of Mulliken population, ∆E
4
and bond order were shown in Fig.4, Table 2 and 3.
1
1
1
1
74
75
76
77
Fig.3 Calculated structure for A, B and C (Note: bond 1-2 and 1-7 ought to be coordinate covalent
bond, but it was shown as single bond in the software)
Table 1 Calculated parameters of A, B and C
Atom i, j Bond length (Å) Atom i, j ,k Bond angle (º) Atom i, j ,k Bond angle (º)
1
1
1
-2
-3
-6
2.429
2.432
2.428
2.431
1.742
1.743
1.743
2-1-3
2-1-6
2-1-7
3-1-7
3-1-6
7-1-6
2-4-3
75.805
128.429
128.512
128.708
128.460
75.740
1-2-4
1-3-4
1-6-8
1-7-8
5-4-2
5-4-3
9-8-6
83.292
83.098
83.404
83.016
120.678
121.516
120.333
A
1-7
2
3
6
-4
-4
-8
117.799
1
1

ACCEPTED MANUSCRIPT
7
4
8
1
1
1
1
2
3
6
7
4
8
1
1
1
1
2
3
6
7
4
8
-8
-5
-9
-2
-3
-6
-7
-4
-4
-8
-8
-5
-9
-2
-3
-6
-7
-4
-4
-8
-8
-5
-9
1.742
1.354
1.352
2.351
2.353
2.349
2.352
1.733
1.735
1.734
1.734
1.348
1.346
2.384
2.384
2.382
2.386
1.743
1.744
1.744
1.744
1.353
1.351
6-8-7
117.759
9-8-7
121.907
2-1-3
2-1-6
2-1-7
3-1-7
3-1-6
7-1-6
2-4-3
6-8-7
76.525
102.935
179.245
103.821
179.392
76.715
1-2-4
1-3-4
1-6-8
1-7-8
5-4-2
5-4-3
9-8-6
9-8-7
84.635
84.540
84.436
84.325
122.486
123.261
122.617
122.865
B
114.251
114.519
2-1-3
2-1-6
2-1-7
3-1-7
3-1-6
7-1-6
2-4-3
6-8-7
77.601
128.796
128.132
128.228
128.444
77.561
1-2-4
1-3-4
1-6-8
1-7-8
5-4-2
5-4-3
9-8-6
9-8-7
82.252
82.256
82.128
82.126
120.902
121.207
120.440
121.747
C
117.887
117.811
1
78
Table 2 The chemical reaction heat for the chelating complexes
Energy of reactant/kJ•mol-1 Energy of products/ kJ•mol-1
ΔE/ kJ•mol-1
-1648
Mn(II)
Cu(II)
-1848752
-2631056
-2864560
-1672112
A
B
C
-5194624
-5977216
-6210576
-1936
Zn(II)
-1792
Dithiocarbamate
1
1
1
1
1
1
79
80
81
82
83
84
∆E refers to the heat released/absorbed during the reaction, the more negative of
the ∆E, the more stable of the product. As shown in Table 2, ∆E for A, B and C was
-1648 kJ/mol, -1936 kJ/mol and -1792 kJ/mol, respectively. Therefore, B was
regarded as the most stable product among these three chelating complexes, C was
less stable than B, and A was the worst stable one.
Bond order is an index of bond strength, which gives an indication of the
1
2

ACCEPTED MANUSCRIPT
1
1
1
1
1
1
1
1
85
86
87
88
89
90
91
92
stability of a bond. Generally, the higher the bond order, the more covalent
components of the bond, the more stable the bond, and the more stable the complex
[44]. As Table 3 illustrated, the bond order between metal ions and S atoms (S1:
single bond S atom, S2: double bond S atom) showed little deviation, which means
that the bond of metal ions-S1 and the bond of metal ions-S2 are almost same, which
-
verified that atoms of S in -CSS are likely to share its electron pair with metal ions to
form coordination bond. And the bond order value of Cu-S was highest, bond order
value of Mn-S was lowest in the DFT calculation, which indicated the covalent bond
between Zn-S was stronger than Mn-S, but weaken than Cu-S.
1
1
93
94
Table 3 The bond order of metal ions and S atoms
Bond order
M-S1
0.599
0.615
0.601
M-S2
0.598
0.614
0.604
Mn-dithiocarbamate
Cu-dithiocarbamate
Zn-dithiocarbamate
1
1
95
96
Where M corresponds to metal ions (Mn, Cu and Zn), S1 represents the single bond S atom in
dithiocarbamate, S2 represents the double bond S atom in dithiocarbamate.
1
1
1
2
2
2
2
2
97
98
99
00
01
02
03
04
Fig.4 showed the partial density of state (PDOS) of the chelating complexes
based on the previous DFT calculation. As the PDOS displayed, there was little
variation between metal ions (Mn, Cu and Zn) and different S atoms (S1 and S2),
which demonstrated that the bond between metal ions and S atoms are almost same.
And the appearance of 3d orbit in S atoms (S1 and S2) indicated that the hybridization
of S atom with metal ions (Mn, Cu and Zn). Furthermore, Fig.4 also showed that the
3d and 4s orbitals of the metal mixed with 3p orbitals of S atom nearby Fermi level.
And the overlap between metal ions with S atoms nearby Fermi level decreased from
1
3

ACCEPTED MANUSCRIPT
2
2
2
2
2
05
06
07
08
09
Cu-S, Zn-S to Mn-S, suggesting the strength of covalent character between Zn-S was
higher than that of Mn-S, but lower than that of Cu-S. In the point view of bond
characterize, Cu-S was the strongest covalent bond among the three chelating
complexes, while the Mn-S covalent bond exhibited the worst strength. Thus, the
stability of these three chelating complexes is decreasing in the order of B, C to A.
2
2
10
11
Fig.4 PDOS of the chelating complexes
2
2
2
12
13
14
3.4. Leakage of metal ions in chelating complexes
The leakage of the metal ions in the cleating complexes as a function of pH, time
and temperature are shown in Fig.5.
1
4

ACCEPTED MANUSCRIPT
2
2
15
16
Time=2h, temperature=30°C
pH=7, temperature=30°C
2
2
2
17
18
19
pH=7, time=2h
Fig.5 The leakage of metal ions as a function of pH, time and temperature
2
2
2
2
2
2
2
2
2
20
21
22
23
24
25
26
27
28
Fig.5 indicated that the dissolution concentrations of heavy metal ions in the
chelates increased with the decreasing pH at constant dissolution time and
temperature, the leakage of heavy metal ions changed minimally when the pH was
higher than 7.01, which revealed that the chelates were much more stable in neutral
2
+
and alkaline environment than acid environment. The maximum leakage of Mn ,
2
+
2+
Cu and Zn were 1.16mg/L, 0.41mg/L and 0.76mg/L when the pH was 3.01 with
the leaching time of 2h at 30°C. And the maximum concentrations of heavy metal
ions were lower than the National Integrated Wastewater Discharge Standards of
China (GB 8978-1996, Mn 2.0 mg/L; Cu 0.5 mg/L; Zn 2.0 mg/L). The leakage of
1
5

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
29
30
31
32
33
34
35
36
37
38
39
heavy metal ions increased slightly with the leaching time increased from 2h to 5h,
and the temperature had little effect on the leakage of heavy metal ions.
The results showed that the three chelating complexes were very stable at pH
values greater than 7.01, and the stability of chelating complexes were in the
following order: B>C>A. It also revealed that the pH had the greatest impact on the
leakage of the heavy metal ions than time and temperature. The highest leakage
concentrations of metal ions in strong acidic environment were lower than the
corresponding discharge standards, thus the chelates would not cause secondary
pollution to environment. In the previous study, DDTCNa had shown high removal
rate of heavy metal ions [20], thus it could be concluded that DDTCNa could be used
to eliminate heavy metals contaminations.
40 4. Conclusions
41
42
43
44
45
46
47
48
49
In this work, C H MnN S , C H CuN S and C H ZnN S , the
10 20 2 4 10 20 2 4 10 20 2 4
four-membered ring chelating complexes were synthesized and characterized by XRD.
The mass loss of C H MnN S , C H CuN S and C H ZnN S started at the
1
0
20
2
4
10 20
2
4
10 20
2 4
temperature of 174.8°C, 197.2°C and 195°C, respectively. The deposing of
C H MnN S was an exothermic process, while the deposing of C H CuN S and
1
0
20
2
4
10 20
2 4
C H ZnN S was an exothermic process. DFT calculation results indicated that ∆E
1
0
20
2 4
decreased in the order of C H CuN S , C H ZnN S toC H MnN S . And the
1
0
20
2
4
10 20
2
4
10 20
2 4
bond strength between Cu and different S atoms was the strongest, while the Mn-S
exhibited the weakest bond strength. Leakage tests revealed these chelating
1
6

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
50
51
52
53
54
complexes were very stable at the neutral and alkaline environment, and the
maximum leakage concentration of Cu(II), Zn(II) and Mn(II) in strong acidic
environment are lower than the limited concentration. And the pH is the most
significant factor for the leakage of the heavy metal ions compared to time and
temperature.
55 Acknowledgements
56
57
This work was supported by the Fundamental Research Funds for Central
Universities under Grant numbers N160105001 and N150101001.
58 Reference
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
[1] D. Sud, G. Mahajan, M. Kaur, Agricultural waste material as potential adsorbent for
sequestering heavy metal ions from aqueous solutions–A review, Bioresource technology 99(14)
(2008) 6017-6027.
[2] A. Zahra, M.Z. Hashmi, R.N. Malik, Z. Ahmed, Enrichment and geo-accumulation of heavy
metals and risk assessment of sediments of the Kurang Nallah—feeding tributary of the Rawal
Lake Reservoir, Pakistan, Science of the Total Environment 470 (2014) 925-933.
[3] A.A. Syukor, S. Sulaiman, M.N.I. Siddique, A. Zularisam, M. Said, Integration of phytogreen
for heavy metal removal from wastewater, Journal of Cleaner Production 112 (2016) 3124-3131.
[4] W.W. Ngah, M. Hanafiah, Removal of heavy metal ions from wastewater by chemically
modified plant wastes as adsorbents: a review, Bioresource technology 99(10) (2008) 3935-3948.
[5] Z. Li, Synthesis of a carbamide-based dithiocarbamate chelator for the removal of heavy metal
ions from aqueous solutions, Journal of Industrial and Engineering Chemistry 20(2) (2014)
586-590.
[6] N.M. Bandaru, N. Reta, H. Dalal, A.V. Ellis, J. Shapter, N.H. Voelcker, Enhanced adsorption
of mercury ions on thiol derivatized single wall carbon nanotubes, Journal of hazardous materials
261 (2013) 534-541.
[7] M. Matouq, N. Jildeh, M. Qtaishat, M. Hindiyeh, M.Q. Al Syouf, The adsorption kinetics and
modeling for heavy metals removal from wastewater by Moringa pods, Journal of Environmental
Chemical Engineering 3(2) (2015) 775-784.
[8] M.M. Matlock, B.S. Howerton, D.A. Atwood, Chemical precipitation of heavy metals from
acid mine drainage, Water research 36(19) (2002) 4757-4764.
[9] J.L. Huisman, G. Schouten, C. Schultz, Biologically produced sulphide for purification of
process streams, effluent treatment and recovery of metals in the metal and mining industry,
Hydrometallurgy 83(1) (2006) 106-113.
1
7

ACCEPTED MANUSCRIPT
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
[10] S. Rengaraj, K.H. Yeon, S.H. Moon, Removal of chromium from water and wastewater by
ion exchange resins, Journal of hazardous materials 87(1) (2001) 273-287.
[11] A. Carreon-Alvarez, A. Herrera-Gonzalez, N. Casillas, R. Prado-Ramirez, M.
Estarron-Espinosa, V. Soto, W. de la Cruz, M. Barcena-Soto, S. Gomez-Salazar, Cu (II) removal
from tequila using an ion-exchange resin, Food chemistry 127(4) (2011) 1503-1509.
[12] G. Crini, Recent developments in polysaccharide-based materials used as adsorbents in
wastewater treatment, Progress in polymer science 30(1) (2005) 38-70.
[13] L.W. Gill, P. Ring, B. Casey, N.M. Higgins, P.M. Johnston, Long term heavy metal removal
by a constructed wetland treating rainfall runoff from a motorway, Science of The Total
Environment 601 (2017) 32-44.
[14] T.A. Kurniawan, G.Y. Chan, W. Lo, S. Babel, Physico–chemical treatment techniques for
wastewater laden with heavy metals, Chemical engineering journal 118(1) (2006) 83-98.
[15] G. Chen, Electrochemical technologies in wastewater treatment, Separation and purification
Technology 38(1) (2004) 11-41.
[16] F. Fu, Q. Wang, Removal of heavy metal ions from wastewaters: a review, Journal of
environmental management 92(3) (2011) 407-418.
[17] B. Guo, B. Liu, J. Yang, S. Zhang, The mechanisms of heavy metal immobilization by
cementitious material treatments and thermal treatments: A review, Journal of Environmental
Management (2017).
[18] P. Desogus, P. Manca, G. Orrù, A. Zucca, Stabilization–solidification treatment of mine
tailings using Portland cement, potassium dihydrogen phosphate and ferric chloride hexahydrate,
Minerals Engineering 45 (2013) 47-54.
[19] B. Kim, W. Gaines, M. Szafranski, E. Bernath, A. Miles, Removal of heavy metals from
automotive wastewater by sulfide precipitation, Journal of environmental engineering 128(7)
(2002) 612-623.
[20] W. Liu, D. Wei, J. Mi, Y. Shen, B. Cui, C. Han, Immobilization of Cu (II) and Zn (II) in
simulated polluted soil using sulfurizing agent, Chemical Engineering Journal 277 (2015)
312-317.
[21] Y. Yang, B. Zuo, J. Li, G. Chen, Studies on the stability of four-membered ring chelates Part
V. The stability of dialkyl dithiocarbamate chelates, Spectrochimica Acta Part A: Molecular and
Biomolecular Spectroscopy 52(14) (1996) 1915-1919.
[22] J. Hou, R. Lu, M. Sun, S.A. Baig, T. Tang, L. Cheng, X. Xu, Effect of heavy metals on the
stabilization of mercury (II) by DTCR in desulfurization solutions, Journal of hazardous materials
217 (2012) 224-230.
[23] R. Abu-El-Halawa, S.A. Zabin, Removal efficiency of Pb, Cd, Cu and Zn from polluted
water using dithiocarbamate ligands, Journal of Taibah University for Science 11(1) (2017) 57-65.
[24] L. Liu, J. Dai, T. Zhao, S. Guo, D. Hou, P. Zhang, J. Shang, S. Wang, S. Han, A novel Zn (ii)
dithiocarbamate/ZnS nanocomposite for highly efficient Cr 6+ removal from aqueous solutions,
RSC Advances 7(56) (2017) 35075-35085.
[25] S. Chen, W. Gong, G. Mei, Q. Zhou, C. Bai, N. Xu, Primary biodegradation of sulfide
mineral flotation collectors, Minerals Engineering 24(8) (2011) 953-955.
[26] L. Liu, Y. Li, X. Liu, Z. Zhou, Y. Ling, Chelating stability of an amphoteric chelating
1
8

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
polymer flocculant with Cu (II), Pb (II), Cd (II), and Ni (II), Spectrochimica Acta Part A:
Molecular and Biomolecular Spectroscopy 118 (2014) 765-775.
[27] A. Costa Jr, G. Ondar, O. Versiane, J. Ramos, T. Santos, A. Martin, L. Raniero, G. Bussi,
C.T. Soto, DFT: B3LYP/6-311G (d, p) vibrational analysis of bis-(diethyldithiocarbamate) zinc
(II) and natural bond orbitals, Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy 105 (2013) 251-258.
[28] A. Costa Jr, J. Ramos, C.T. Soto, A. Martin, L. Raniero, G. Ondar, O. Versiane, L. Moraes,
Fourier Transform Infrared and Raman spectra, DFT: B3LYP/6-311G (d, p) calculations and
structural properties of bis (diethyldithiocarbamate) copper (II), Spectrochimica Acta Part A:
Molecular and Biomolecular Spectroscopy 105 (2013) 259-266.
[29] J.P. Perdew, Y. Wang, Accurate and simple analytic representation of the electron-gas
correlation energy, Physical Review B 45(23) (1992) 13244.
[30] H. Zhen, Q. Xu, Y. Hu, J. Cheng, Characteristics of heavy metals capturing agent
dithiocarbamate (DTC) for treatment of ethylene diamine tetraacetic acid–Cu (EDTA–Cu)
contaminated wastewater, Chemical engineering journal 209 (2012) 547-557.
[31] M.A.S. Khan, B. Ganguly, Can surface energy be a parameter to define morphological
change of rock-salt crystals with additives? A first principles study, CrystEngComm 15(14)
(2013) 2631-2639.
[32] J. Zhao, F. Zhao, S. Xu, X. Ju, DFT Studies on Doping Effect of Al12X: Adsorption and
Dissociation of H2O on Al12X Clusters, The Journal of Physical Chemistry A 117(10) (2013)
2213-2222.
[33] Z. Wang, Z. Zhai, L. Wang, J. Chen, O. Kikuchi, T. Watanabe, Prediction of gas phase
thermodynamic function of polychlorinated dibenzo-p-dioxins using DFT, Journal of Molecular
Structure: THEOCHEM 672(1) (2004) 97-104.
[34] M. Bonamico, G. Dessy, A. Mugnoli, A.t. Vaciago, L. Zambonelli, Structural studies of
metal dithiocarbamates. II. The crystal and molecular structure of copper diethyldithiocarbamate,
Acta Crystallographica 19(6) (1965) 886-897.
[35] M. Bonamico, G. Mazzone, A. Vaciago, L. Zambonelli, Structural studies of metal
dithiocarbamates. III. The crystal and molecular structure of zinc diethyldithiocarbamate, Acta
Crystallographica 19(6) (1965) 898-909.
[36] E. Musellim, M.H. Tahir, M.S. Ahmad, S. Ceylan, Thermokinetic and TG/DSC-FTIR study
of pea waste biomass pyrolysis, Appl Therm Eng 137 (2018) 54-61.
[37] M. Labus, M. Lempart, Studies of Polish Paleozoic shale rocks using FTIR and TG/DSC
methods, J Petrol Sci Eng 161 (2018) 311-318.
[38] R.G. Pearson, Hard and Soft Acids and Bases, Journal of the American Chemical Society
85(22) (1963) 3533-3539.
[39] J.H. Van Vleck, Theory of the Variations in Paramagnetic Anisotropy Among Different Salts
of the Iron Group, Physical Review 41(2) (1932) 208-215.
[40] J.t. Dunitz, L. Orgel, Electronic properties of transition-metal oxides-II: cation distribution
amongst octahedral and tetrahedral sites, Journal of Physics and Chemistry of Solids 3(3-4) (1957)
318-323.
[41] L. Pauling, The nature of the chemical bond. Application of results obtained from the
1
9

ACCEPTED MANUSCRIPT
3
3
3
3
3
3
3
67
68
69
70
71
72
73
quantum mechanics and from a theory of paramagnetic susceptibility to the structure of molecules,
Journal of the American Chemical Society 53(4) (1931) 1367-1400.
[42] J. Bjerrum, P. Andersen, Metal ammine formation in aqueous solution, Munksgaard1945.
[43] J.R. Gissinger, B.D. Jensen, K.E. Wise, Modeling chemical reactions in classical molecular
dynamics simulations, Polymer 128 (2017) 211-217.
[44] D.W. Hou, Z.H. Yang, S.L. Pan, Electronic, bond order, linear optical properties of series of
alkalimetal P-O-P linkage borophosphates, J Alloy Compd 706 (2017) 589-595.
3
74
2
0

ACCEPTED MANUSCRIPT
Highlights

DDTCNa was used to immobilize heavy metal ions (Mn, Cu and Zn)
Stability of chelating complexes decreased in the order of

C
10
H
20CuN
2
S
4
> C10
H
20ZnN
2
S4
> C10
H
20MnN
2
S4 based on thermal analysis,
DFT calculation and leakage tests
The maximum leakage concentration of heavy metal ions was lower
than the limited standard concertation

2
1

ACCEPTED MANUSCRIPT
Graphical Abstract
2
2