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Removal of endrin and dieldrin isomeric pesticides through stereoselective adsorption behavior on the graphene oxide-magnetic nanoparticles

Kamlesh Shrivas,1,2* Archana Ghosale,1 Nidhi Nirmalkar, 1 Arti Shrivastava,1 Sunil Kumar Shingh1 and Sandip S.Shinde3

1Department of Chemistry, Guru Ghasidas Vishwavidyalaya, Koni, Bilaspur, CG

2School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, CG-492010, Inia

3Organic Chemistry Division; National Chemical Laboratory, Dr.Homi Bhabha Road, Pune-411008, India

*Corresponding author:

Phone: +91-7752-260488

Fig.S1. Structure of endrin and dieldrin

Table S1. Chemical characteristics of Endrin
IUPAC name / : 1R, 2S, 3R, 6S, 7R, 8S, 9S, 11R)-3,4,5,13,13-Hexchloro- 10-oxapentacyclo[6.3.1.1.0.0]tridec-4-ene
Chemical formula / : C12H8Cl6O
CAS number / : 72-20-8
Molar mass / : 380.907 g mol-1
Appearance / : Colorless to light tan crystals
Density / : 1.77 g cm-3
Melting point / : 200 oC
Vapor pressure / : 2.6x10-6 Pa
Flash point / : Non Combustible
LD50 / : 1.4 mg Kg-1 (oral, mouse)
Table S2. Chemical characteristics of Dieldrin
IUPAC name / : 1aR, 2R, 2aS, 3S, 6R, 6aR, 7S, 7aS)-3,4,5,6,9,9-Hexchloro- 1a,2,2a,3,6,6a,7,7a-octahydro-2,7,3:6-dimthanonaphtho[2,3-b]oxirene
Chemical formula / : C12H8Cl6O
CAS number / : 60-57-1
Molar mass / : 380.91 g mol-1
Appearance / : Colorless to light tan crystals
Density / : 1.75 g cm-3
Melting point / : 176 oC
Flash point / : Non Combustible
Main hazards / : Potential carcinogen
LD50 / : 38 mg Kg-1 (oral, mouse)

Removal Percentage (%)

The extent of removal % of endrin and dieldrin was calculated by the following equation

R% =Co-CfCo × 100%

Where R% = removal percentage,

m = mass of GO-MNPs

Co = initial concentration of pesticides

Cf = final concentration pesticide after the removal with GO-MNPs

Table S3. The values of Co and Cf for dieldrin used for removal %
m (g) / Co (g L-1) / Cf (g L-1) / Co-CfCo / Co-CfCo× 100%
0.005 / 0.005 / 0.0033 / 0.3330 / 33.30
0.010 / 0.005 / 0.0022 / 0.5541 / 55.41
0.015 / 0.005 / 0.0017 / 0.6458 / 64.58
0.020 / 0.005 / 0.0016 / 0.6706 / 67.70
0.025 / 0.005 / 0.0012 / 0.7587 / 75.87
0.030 / 0.005 / 0.0010 / 0.7972 / 79.72
Table S4. The values of Co and Cf for endrin used for removal %
m (g) / C0 (g L-1) / Cf (g L-1) / Co-CfCo / Co-CfCo× 100%
0.005 / 0.005 / 0.0023 / 0.5393 / 53.93
0.010 / 0.005 / 0.0017 / 0.6454 / 64.54
0.015 / 0.005 / 0.0012 / 0.7515 / 75.15
0.020 / 0.005 / 0.0010 / 0.7898 / 78.98
0.025 / 0.005 / 0.0010 / 0.7838 / 78.38
0.030 / 0.005 / 0.0006 / 0.8636 / 86.36

Langmuir adsorption isotherm model:

Qe or xm = (Co-Ce)Co

xm = abCe1+aCe

CeQe = 1ab + 1bCe

Where, the plot of Ce/(x/m) verses Ce as a straight line. The slope and intercept is used to find constants a and b

Ce is the equilibrium concentration.

x/m or Qe = amount of pesticides adsorbed per unit weight of adsorbent

a = adsorption capacity

b = affinity of the binding sites.

Dieldrin

Table S5. The values of m, Qe, Ce for dieldrin used for calculation of Langmuir adsorption isotherm model
m (g) / Qe=x/m (mg g-1) / Ce (mg L-1) / Ce/Qe
0.005 / 0.000135 / 5 / 2290.678
0.010 / 0.000282 / 10 / 7657.101
0.015 / 0.000331 / 15 / 14797.04
0.020 / 0.000267 / 20 / 25027.56
0.025 / 0.000225 / 25 / 39407.92
0.030 / 0.000241 / 30 / 51504.08

Endrin

Table S6. The values of m, Qe, Ce for endrin used for calculation of Langmuir adsorption isotherm model
m (g) / Qe=x/m (mg g-1) / Ce (mg L-1) / Ce/Qe
0.005 / 0.000408 / 5 / 12254.11
0.010 / 0.000339 / 10 / 29458.55
0.015 / 0.000264 / 15 / 56866.72
0.020 / 0.000207 / 20 / 96438.83
0.025 / 0.000186 / 25 / 134469.2
0.030 / 0.000163 / 30 / 184277

Pseudo-first-order and pseudo-second-order kinetic model:

Models / Equations
Pseudo-first-order kinetic / Log (Qe-Qt) =log Qe-K1 t2.303
pseudo-second-order kinetic / tQt=1K2Qe2+tQe

Where,

t = contact time

Qt = amount of pesticides adsorbed per unit weight of adsorbent in particular time

Qe = amount of pesticides adsorbed per unit weight of adsorbent

K1 and K2 are kinetic rate constants.

Dieldrin

Table S7. The values of t, m, Qt for calculation of pseudo-second order for dieldrin
t (min) / m (g) / Qt (mg g-1 of GO-MNPs) / t/Qt (min/g mg-1)
2 / 0.03 / 0.0067 / 296.54
5 / 0.03 / 0.0150 / 331.26
10 / 0.03 / 0.0235 / 423.90
15 / 0.03 / 0.0326 / 459.41
20 / 0.03 / 0.0378 / 528.37
25 / 0.03 / 0.0426 / 586.06
30 / 0.03 / 0.0447 / 670.58
Table S8. The values of t, m, Qt for calculation of pseudo-first order for endrin
t (min) / m (g) / Qt (mg g-1 of GO-MNPs)
2 / 0.03 / 0.0002
5 / 0.03 / 0.0023
10 / 0.03 / 0.0060
15 / 0.03 / 0.0096
20 / 0.03 / 0.0129
25 / 0.03 / 0.0156
30 / 0.03 / 0.0195