. 2020 Nov 16;7:36. doi: 10.1186/s40580-020-00245-4

Table 2.

Published papers in heavy metal removal using AMs

AMs	Adsorbents	Heavy metal ions	Removal efficiency (%)	Maximum adsorption capacity (mg g⁻¹)	pH	Recycling method	Desorption efficiency (%)	Recycle number	Refs.
PMs	CTS/PEG nCTS ECH-cCTS GLA-cCTS nCTS ECH-cCTS GLA-cCTS CTS PVT-co-PAN PVA/PEI CTS/PVA/PEI CA/PEI	Fe²⁺, Mn²⁺ Hg²⁺ Hg²⁺ Hg²⁺ Cr⁶⁺ Cr⁶⁺ Cr⁶⁺ Cu²⁺ Cu²⁺ Pb²⁺, Cd²⁺, Cu²⁺ Cd²⁺, Cu²⁺, Ni²⁺ Cu²⁺	– 15.1 18.3 35.2 37.9 45.5, 92.0 86.9, 31.7 97.2 87.4 60.0, 26.0, 16.0 74.8, 57.4, 50.3 14.8	38.0, 18.0 25.3 30.3 75.5 885.0 270.0, 1420.0 950.0, 347.0 87.5 44.3 122.2, 37.1, 29.9 112.1, 86.1, 75.5 7.4	5.0, 5.9 6.0 6.0 6.0 6.0 2.0, 6.0 2.0, 6.0 5.0 5.0 5.0 6.0 5.0	0.1 M HCl 1 M NaCl, 10^–4 M EDTA 1 M NaCl, 10^–4 M EDTA 1 M NaCl, 10^–4 M EDTA 1 M NaCl 1 M NaCl 1 M NaCl 0.03 M H₂SO₄ 0.25 mM HCl, 0.25 mM EDTA 0.05 M HCl, 0.05 M HNO₃ 0.05 M Na₂EDTA 0.1 M HCl	> 98.0 73.1, 52.3 86.6, 50.5 43.2, 19.9 48.6 77.2, 49.1 40.3, 35.7 ~ 35.0 ~ 78.0, ~ 96.0 98.8, 61.8 (Cu²⁺) ~ 80.0 10.5	4 – – – 3 3 3 5 – 5 4 3	[48] [50] [50] [50] [52] [52] [52] [130] [129] [53] [54] [55]
PCMs	PANOB CMC Al oxide-CMC Fe oxide-CMC Fe oxide-PE₈M Fe oxide-PE₂₅M CPBC PANlB CCPM	Cu²⁺, Zn²⁺, Cd²⁺ Se⁴⁺ Se⁴⁺ Se⁴⁺ Cr⁶⁺ Cr⁶⁺ Cu²⁺, Zn²⁺, Cd²⁺, Ni²⁺ U⁶⁺ Cu²⁺, Pb²⁺	99.8, 98.9, 97.4 19.0 19.0 15.0 95.0 84.0 95.0, 95.0, 85.0, 70.0 70.5 96.0, 99.5	77.4, 65.4, 52.6 18.4 17.2 8.2 8.8 7.7 88.5, 72.9, 51.5, 48.5 14.1 9.6, 19.9	2.0–7.0 4.0–4.5 4.0–4.5 4.0–4.5 1.0–9.0 1.0–9.0 6.0, 7.0, 6.0, 8.0 5.0 6.5, 6.0	0.1 M HCl NaCl NaCl, NaOH – HCl, NaOH – 0.05 M Ca(NO₃)₂, 0.05 M EDTA, 0.05 M DTPA 0.1 M HCl 0.1 M HNO₃; 0.01 M EDTA	> 90.0 11.0 15.0, 44.0 – 90.0 – > 90.0 ~ 68.0 72.1, 66.7; 75.3, 68.0	4 – – – – – – 7 –	[58] [59] [59] [59] [60] [60] [65] [66] [67]
ENMs	AOPAN/RC PEI/PVA PEI/PES TC PAN/PVA PVA CTS PVA/CTS CNC/CTS/PVA-SH PAN/CTS PEI/CTS	Fe³⁺, Cu²⁺, Cd²⁺ Cu²⁺, Cd²⁺, Pb²⁺ Pb²⁺, Cu²⁺, Cd²⁺ Cu²⁺, Cd²⁺, Pb²⁺ Cr⁶⁺, Cd²⁺ Cu²⁺, Pb²⁺ Ni²⁺, Cu²⁺ Ni²⁺, Co²⁺ Cu²⁺, Pb²⁺ Cd²⁺, Pb²⁺ Cr⁶⁺, Cu²⁺, Co²⁺	31.2, 11.5, 2.9 23.0, 25.6, 32.8 90.4, 89.8, 93.2 4.9, 4.6, 2.2 33.3, 28.0 – 46.0, 68.7 79.3, 77.1 39.4, 44.8 51.1, 52.9 50.33, 27.3, 19.3	417.2, 270.7, 127.0 70.9, 121.9, 94.3 94.3, 161.3, 357.1 49.0, 45.9, 22.0 66.5, 33.6 58.3, 161.7 10.3, 25.6 23.9, 10.0 484.1, 323.5 385.0, 240.0 139.0, 69.3, 68.3	2.0, 5.0, 6.0 5.0 5.0–7.0 2.0–7.0 2.0, 6.0 – 5.0 6.0 6.0 7.0, 5.0 2.0, 4.0, 6.0	0.1 M HCl 0.05 M EDTA, 0.05 M HCl, 0.05 M HNO₃ 0.05 M EDTA – 0.1 M NaOH, 1 M HNO₃ – EDTA – 4 M HCl – 0.01 M HCl, 0.01 M NaOH	> 70.0 95.6, 51.4, 20.7 (Cu²⁺) 96.2, 98.2, 97.2 – > 90.0 – 32.2, 41.8 – 90.6, 90.2 – 40.3, 21.0, 13.3	5 3 3 – 3 – 3 – 4 – 5	[84] [86] [89] [98] [85] [81] [96] [94] [97] [100] [99]
NEMs	CCGO GO/PSf GO/PVA GO/cellulose AgNPs-St-PEG-AcANCH PAN/MO/CTS PAN/MO pHEMA/CTS CTS/HAp CTS/PVA/Zeo MOFs Zr-MOFs	Cr⁶⁺ Cu²⁺, Cd²⁺, Pb²⁺, Cr⁶⁺ Cu²⁺, Ni²⁺, Cd²⁺ Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺ Hg²⁺ Cd²⁺, Pb²⁺ Cd²⁺, Pb²⁺ Cd²⁺, Pb²⁺, Hg²⁺ Pb²⁺, Co²⁺, Ni²⁺ Cr⁶⁺, Fe³⁺, Ni²⁺ Cu²⁺ Cu²⁺	81.2 > 90.0 72.6, 62.3, 83.8 > 90.0 (from Co²⁺ to Cd²⁺), 100.0 (Pb²⁺) ~ 90.0, 85.0 61.2, 86.0 36.4, 77.2 37.6, 25.1, 78.4 78.5, 80.0, 55.5 ~ 100.0, 93.0, 98.0 6.0 98.8	67.7 75.0, 68.0, 79.0, 154.0 72.6, 62.3, 83.8 15.5, 14.3, 26.6, 16.7, 26.8, 107.9 158.2, 182.5 461.0, 390.0 91.0, 193.0 18.5, 22.7, 68.8 296.7, 213.8, 180.2 8.8, 6.2, 1.8 59.8 988.2	3.0 6.5, 6.4, 6.7, 3.5 5.7 4.5 7.0, 6.0 7.0, 5.0 7.0, 5.0 5.0 – – 6.0 6.0	0.1 M NaOH DI H₂O/HCl 1 M HCl 0.1 M HNO₃ – – 0.01 M HNO₃ 1 M HNO₃ DI H₂O – –	76.9 ~ 90.0 64.7, 54.8, 75.2 ~ 98.0 (Pb²⁺) – – > 95.0 75.4, 72.5, 52.4 99.0, 92.0, 96.0 – –	5 3 6 10 – – – 5 5 5 – –	[118] [120] [26] [121] [128] [100] [100] [122] [123] [104] [124] [124]

AMs

Adsorbents

Heavy metal ions

Removal efficiency (%)

Maximum adsorption capacity (mg g⁻¹)

Recycling method

Desorption efficiency (%)

Recycle number

Refs.

PMs

CTS/PEG

nCTS

ECH-cCTS

GLA-cCTS

nCTS

ECH-cCTS

GLA-cCTS

CTS

PVT-co-PAN

PVA/PEI

CTS/PVA/PEI

CA/PEI

Fe²⁺, Mn²⁺

Hg²⁺

Cr⁶⁺

Cu²⁺

Pb²⁺, Cd²⁺, Cu²⁺

Cd²⁺, Cu²⁺, Ni²⁺

Cu²⁺

–

15.1

18.3

35.2

37.9

45.5, 92.0

86.9, 31.7

97.2

87.4

60.0, 26.0, 16.0

74.8, 57.4, 50.3

14.8

38.0, 18.0

25.3

30.3

75.5

885.0

270.0, 1420.0

950.0, 347.0

87.5

44.3

122.2, 37.1, 29.9

112.1, 86.1, 75.5

7.4

5.0, 5.9

6.0

2.0, 6.0

5.0

6.0

5.0

0.1 M HCl

1 M NaCl,

10^–4 M EDTA

1 M NaCl,

10^–4 M EDTA

1 M NaCl,

10^–4 M EDTA

1 M NaCl

0.03 M H₂SO₄

0.25 mM HCl,

0.25 mM EDTA

0.05 M HCl, 0.05 M HNO₃

0.05 M Na₂EDTA

0.1 M HCl

> 98.0

73.1, 52.3

86.6, 50.5

43.2, 19.9

48.6

77.2, 49.1

40.3, 35.7

~ 35.0

~ 78.0, ~ 96.0

98.8, 61.8 (Cu²⁺)

~ 80.0

10.5

–

[48]

[50]

[52]

[130]

[129]

[53]

[54]

[55]

PCMs

PANOB

CMC

Al oxide-CMC

Fe oxide-CMC

Fe oxide-PE₈M

Fe oxide-PE₂₅M

CPBC

PANlB

CCPM

Cu²⁺, Zn²⁺, Cd²⁺

Se⁴⁺

Cr⁶⁺

Cu²⁺, Zn²⁺,

Cd²⁺, Ni²⁺

U⁶⁺

Cu²⁺, Pb²⁺

99.8, 98.9, 97.4

19.0

15.0

95.0

84.0

95.0, 95.0, 85.0, 70.0

70.5

96.0, 99.5

77.4, 65.4, 52.6

18.4

17.2

8.2

8.8

7.7

88.5, 72.9,

51.5, 48.5

14.1

9.6, 19.9

2.0–7.0

4.0–4.5

1.0–9.0

6.0, 7.0,

6.0, 8.0

5.0

6.5, 6.0

0.1 M HCl

NaCl

NaCl, NaOH

–

HCl, NaOH

–

0.05 M Ca(NO₃)₂,

0.05 M EDTA, 0.05 M DTPA

0.1 M HCl

0.1 M HNO₃; 0.01 M EDTA

> 90.0

11.0

15.0, 44.0

–

90.0

–

> 90.0

~ 68.0

72.1, 66.7; 75.3, 68.0

–

[58]

[59]

[60]

[65]

[66]

[67]

ENMs

AOPAN/RC

PEI/PVA

PEI/PES

PAN/PVA

PVA

CTS

PVA/CTS

CNC/CTS/PVA-SH

PAN/CTS

PEI/CTS

Fe³⁺, Cu²⁺, Cd²⁺

Cu²⁺, Cd²⁺, Pb²⁺

Pb²⁺, Cu²⁺, Cd²⁺

Cu²⁺, Cd²⁺, Pb²⁺

Cr⁶⁺, Cd²⁺

Cu²⁺, Pb²⁺

Ni²⁺, Cu²⁺

Ni²⁺, Co²⁺

Cu²⁺, Pb²⁺

Cd²⁺, Pb²⁺

Cr⁶⁺, Cu²⁺, Co²⁺

31.2, 11.5, 2.9

23.0, 25.6, 32.8

90.4, 89.8, 93.2

4.9, 4.6, 2.2

33.3, 28.0

–

46.0, 68.7

79.3, 77.1

39.4, 44.8

51.1, 52.9

50.33, 27.3, 19.3

417.2, 270.7, 127.0

70.9, 121.9, 94.3

94.3, 161.3, 357.1

49.0, 45.9, 22.0

66.5, 33.6

58.3, 161.7

10.3, 25.6

23.9, 10.0

484.1, 323.5

385.0, 240.0

139.0, 69.3, 68.3

2.0, 5.0, 6.0

5.0

5.0–7.0

2.0–7.0

2.0, 6.0

–

5.0

6.0

7.0, 5.0

2.0, 4.0, 6.0

0.1 M HCl

0.05 M EDTA, 0.05 M HCl, 0.05 M HNO₃

0.05 M EDTA

–

0.1 M NaOH, 1 M HNO₃

–

EDTA

–

4 M HCl

–

0.01 M HCl, 0.01 M NaOH

> 70.0

95.6, 51.4, 20.7 (Cu²⁺)

96.2, 98.2, 97.2

–

> 90.0

–

32.2, 41.8

–

90.6, 90.2

–

40.3, 21.0, 13.3

–

[84]

[86]

[89]

[98]

[85]

[81]

[96]

[94]

[97]

[100]

[99]

NEMs

CCGO

GO/PSf

GO/PVA

GO/cellulose

AgNPs-St-PEG-AcANCH

PAN/MO/CTS

PAN/MO

pHEMA/CTS

CTS/HAp

CTS/PVA/Zeo

MOFs

Zr-MOFs

Cr⁶⁺

Cu²⁺, Cd²⁺, Pb²⁺, Cr⁶⁺

Cu²⁺, Ni²⁺, Cd²⁺

Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺

Hg²⁺

Cd²⁺, Pb²⁺

Cd²⁺, Pb²⁺, Hg²⁺

Pb²⁺, Co²⁺, Ni²⁺

Cr⁶⁺, Fe³⁺, Ni²⁺

Cu²⁺

81.2

> 90.0

72.6, 62.3, 83.8

> 90.0 (from Co²⁺ to Cd²⁺), 100.0 (Pb²⁺)

~ 90.0, 85.0

61.2, 86.0

36.4, 77.2

37.6, 25.1, 78.4

78.5, 80.0, 55.5

~ 100.0, 93.0, 98.0

6.0

98.8

67.7

75.0, 68.0, 79.0, 154.0

72.6, 62.3, 83.8

15.5, 14.3, 26.6, 16.7, 26.8, 107.9

158.2, 182.5

461.0, 390.0

91.0, 193.0

18.5, 22.7, 68.8

296.7, 213.8, 180.2

8.8, 6.2,

1.8

59.8

988.2

3.0

6.5, 6.4, 6.7, 3.5

5.7

4.5

7.0, 6.0

7.0, 5.0

5.0

–

6.0

0.1 M NaOH

DI H₂O/HCl

1 M HCl

0.1 M HNO₃

–

0.01 M HNO₃

1 M HNO₃

DI H₂O

–

76.9

~ 90.0

64.7, 54.8, 75.2

~ 98.0 (Pb²⁺)

–

> 95.0

75.4, 72.5, 52.4

99.0, 92.0, 96.0

–

[118]

[120]

[26]

[121]

[128]

[100]

[122]

[123]

[104]

[124]

nCTS natural CTS, ECH-cCTS ECH crosslinked CTS, GLA-cCTS GLA crosslinked CTS, PVT poly(vinyl tetrazole), PANOB PAN/organobentonite, CMC CTS/montmorillonite composite, Al oxide-CMC Al₂O₃/CTS/montmorillonite composite, Fe oxide-CMC Fe₃O₄/CTS/montmorillonite composite, Fe oxide-PE₈M Fe₃O₄/PEI800/montmorillonite, Fe oxide-PE₂₅M Fe₃O₄/PEI2500/montmorillonite, CPBC CTS-grafted-PAA-bentonite composites, PANlB poly(aniline) modified bentonite, CCPM crosslinked CTS/Al₁₃-pillared montmorillonite, AgNPs-St-PEG-AcANCH AgNPs-base starch/PEG-PAA nanocomposite hydrogel, MO metal oxide, DI H₂O distilled water, HCl hydrochloric acid, HNO₃ nitric acid, NaOH sodium hydroxide, NaCl sodium chloride, EDTA ethylenediaminetetraacetic acid, Na₂EDTA EDTA disodium salt, H₂SO₄ sulfuric acid, Ca(NO₃)₂ calcium nitrate, DTPA diethylenetriaminepentaacetic acid