Adsorptive removal of anionic dyes from aqueous solution using nanoporous magnesium aluminophosphate material

Adsorptive removal of anionic dyes from aqueous solution using nanoporous magnesium aluminophosphate material

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Available online at www.sciencedirect.com

ScienceDirect Materials Today: Proceedings 5 (2018) 8812–8817

www.materialstoday.com/proceedings

ICRAMC_2017

Adsorptive removal of anionic dyes from aqueous solution using nanoporous magnesium aluminophosphate material K. Sivakamia, K. Muthurajab, C. Kannanc,* a

Department of Chemistry, Salem Sowdeswari College, Salem – 636010, Tamilnadu, India Department of Chemistry, Pope’s College, Sawerpuram, Tuticorin – 628251, Tamilnadu, India c Department of Chemistry, Manonmaniam Sundaranar University, Tirunelveli-12, Tamilnadu, India b

Abstract In this investigation, the removal of anionic dyes Indigo carmine (IC) and Fast yellow (FY) has been studied by using nanoporous magnesium aluminophosphate material as adsorbent. The synthesised magnesium aluminophosphate material was characterised by FT-IR, XRD and Nitrogen sorption analysis. To find the maximum adsorption of anionic dyes on adsorbent, the experiment was carried out at various adsorption conditions like contact time, dye concentration, temperature and adsorbent dosage. Adsorption equilibrium was achieved at 20 minutes and the adsorption was followed pseudo second order kinetics. The negative G value showed that adsorption was spontaneous. The enthalpy (H for IC = 40.28kJ/mol, FY = 40.73 kJ/mol) indicated that the adsorption was endothermic and chemisorption. © 2017 Published by Elsevier Ltd. Selection and/or Peer-review under responsibility of International Conference On Recent Advances In Material Chemistry. Keywords:aluminophosphate; nanoporous; Indigo carmine; Fast yellow; adsorption kinetics

1. Introduction The literature reviews on environmental pollution due to dyes are alarming the living organisms [1-3]. A number of methods available for the treatment of dye polluted water. Among these methods adsorption method is inexpensive and best method. Several materials such as biomaterials and synthetic materials are reported as adsorbents for the removal of organic dyes from dye effluent [4-6]. The application of nanoporous Mg-AlPO4 material as adsorbent for the removal of organic dyes is not yet reported. The porous materials are classified as nanoporous materials when its pore size is in between 0nm to 100nm. These porous materials are synthesized by using structure directing agents [7-9] and they have many applications [10]. The scope of the present investigation is to synthesis nanoporous Mg-AlPO4 material by using the lauric and myristic triglycerides as structure directing agent and it is used as adsorbent for the removal of anionic dyes, Indigo Carmine (IC) and Fast Yellow (FY).

* Corresponding author. Tel.: +91 9443507036 E-mail address:[email protected] 2214-7853© 2017 Published by Elsevier Ltd. Selection and/or Peer-review under responsibility of International Conference On Recent Advances In Material Chemistry.

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2. Materials and methods Nanoporous magnesium aluminophosphate (Mg-AlPO4) material was used as adsorbent and the anionic dyes Indigo carmine (IC) and Fast yellow (FY) were used as adsorbates. The physical characteristic parameters are given in Table-1. The adsorbent Mg-AlPO4 was synthesised by using the following procedure: The mixture of 0.01 mol of lauric and 0.01 mol of myristic triglyceride was added as template with the 10.67g of Aluminum chloride in 40 ml of distilled water. In addition to that 9.8 g of phosphoric acid in 20ml of distilled water was added slowly with continuous stirring for one hour. Then 4.07g of magnesium chloride in 20ml of distilled water was added and the mixture was heated on hot plate at 130oC with stirring for 6 hours. After attaining the complete crystallization, the sample was washed with distilled water and calcinated at 600oC. The sample was characterized by FT-IR, XRD and N2 sorption analysis to find out the structural formation, mesophase formation and surface area respectively.The batch adsorption method was carried out at various experimental conditions. In order to identify the concentration of dye solution, UV/VIS spectrophotometer (Perkin Elmer), Lambda 25 was used. Table 1. Physical characteristic parameters of dyes. Parameters

Indigo carmine (IC)

Molecular formula

C16H8N2Na2O8S2 H

Chemical Structure

NaO 3S

Fast Yellow (FY) C13H9N3Na2O6S2

O

N N O

SO 3Na

H

Formula weight (g/mol)

466.36

401.34

C.I number

73015

13015

Colour

Blue

Yellow

Maximum absorption max(nm)

612

488

Adsorption percentage of dyes on Mg-AlPO4 was calculated by using the following equation.

Adsorption percentage (%) 

(C0  Ce) V X 100 W

(1)

Where; C0 ..Initial dye concentrations in solution (mg L-1) Ce ..Final dye concentrations in solution (mg L-1) V ...Volume of dye solution (L) W .. Weight of Mg-AlPO4 (g) 3. Results and Discussion 3.1. Characterization The characteristic FT-IR peaks are appeared at 1100 cm-1, 672 cm-1 and 459 cm-1. These peaks confirm the formation of tetrahedral framework of Mg-AlPO4 (Fig.1). The XRD pattern of Mg-AlPO4 is given in Fig.2, which consists of relatively one reflection at low 2θ value 1.14o with the d-spacing of about 78 Å. The XRD peak at low angle is typical for mesoporous materials (nanoporous material which has pore diameter between 2nm and 50nm) [11]. The pore size distribution (diameter) of Mg-AlPO4 is given in Fig.3 and it is maximum at 20nm (200 Å) and the nanoporous Mg-AlPO4 has the surface area 86 m2/g.

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Fig. 1. FT-IR spectrum of nanoporous Mg-AlPO4

Fig. 2. Powder XRD spectrum of nanoporous Mg-AlPO4

Fig. 3. N2 sorption isotherm and pore distribution plot for nanooporous Mg-AlPO4

3.2 Adsorption study Adsorption process was conducted at various experimental conditions in order to optimize the condition for maximum dye adsorption. a. Effect of contact time Effect of contact time was carried out upto adsorption equilibrium time. Adsorption equilibrium for both dyes was obtained at 20 minutes. After the adsorption equilibrium time, the contact time was not influence the percentage of adsorption (Fig.4). b. Effect of dye concentration The effect of dye concentration for the adsorption of IC and FY on nanoporous Mg-AlPO4 was studied in the dye concentration ranges from 100 mg L-1 to 500mg L-1 and it is shown in Fig.5. Adsorption percentage was decreased with increase of dye concentration. In adsorption process, the dye molecules were adsorbed on the active sites of nanoporous Mg-AlPO4. At lower dye concentration (100 mg L-1), due to the availability of high active sites on surface of Mg-AlPO4, the percentage of adsorption was high. Saturation of active sites on surface area was attained at high concentration and hence the percentage of adsorption was decreased.

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c. Effect of temperature The effect of temperature for the adsorption of IC and FY on nanoporous Mg-AlPO4 was shown in Fig.6. The percentage of adsorption of both dyes was increased with increase of temperature from 30oC to 70oC (303K – 343K). It was due to the active sites on the surface of the nanoporous Mg-AlPO4 were activated at high temperature and hence the adsorption percentage was maximum at high temperature (343K). d. Effect of adsorbent dosage The Adsorption of anionic dyes (FY, IC) on nanoporous Mg-AlPO4 materials was also influenced by the amount of adsorbent. Hence the adsorption experiment was carried out by vary the adsorbent dosage from 0.5g to 2.5g. The percentage of adsorption of organic dyes was increased with increase of adsorbent dosage. When adsorbent amount was increasing, the amount of surface area as well as the number of active sites was increased. Hence adsorption percentage was increased and it is shown in Fig.7.

Fig. 4. Effect of contact time for adsorption of IC and FY (Dye concentration: 100mgL-1, Temperature: 30oC, Adsorbent dosage: 0.5g)

Fig. 6. Effect of temperature for adsorption adsorption of IC and FY (Contact time: 20 minutes, Dye concentration: 500mgL-1, Adsorbent dosage: 0.5g)

Fig. 5. Effect of dye concentration for adsorption of IC and FY (Contact time: 20 minutes, Temperature: 30oC, Adsorbent dosage: 0.5 g)

Fig. 7. of adsorbent dosage for adsorption of IC and FY (Contact time: 20 minutes, Dye concentration: 500 mg L-1, Temperature: 30 oC)

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3.2.1 Adsorption kinetics All The rate of adsorption of organic dyes on adsorbent was calculated by using adsorption kinetics. The pseudo second order kinetic model is based on adsorption equilibrium capacity and is expressed as follows,

t Qt

1



k 2Qe

1



2

Qe

t

(2)

Where, k2 … rate constant of pseudo second order kinetics (g/m/ min) Qe… amount of dye adsorbed per unit mass of the adsorbent at equilibrium (mg/ g) Qt … amount of dye adsorbed per unit mass of the adsorbent at time t (mg/g) t … time (minutes). The values of linear regression coefficients (R2) obtained from the experiments were very close to 1(Table 2). These results indicated that the adsorption of both dyes (IC and FY) on nanoporous Mg-AlPO4 were followed the pseudo second order kinetics. Based on kinetic parameters, FY was rapidly adsorbed than IC. Table 2. Pseudo second order kinetic data for adsorption of IC and FY on nanoporous Mg-AlPO4 Dyes

Qe

k2

R2

FY

7.77

0.136

0.9996

IC

8.05

0.100

0.9992

3.2.2 Adsorption thermodynamics The thermodynamic parameters such as Free energy (G), enthalpy (H) and entropy (S) have an important role to determine spontaneity and heat exchange of the adsorption process. They were calculated using the following relations. G  H  TS

(3)

ΔG  -RT ln K D

(4)

K D  qe Ce

(5)

From the equations (3) and (4), ln K D 

ΔS R



ΔH RT

(6)

Where; KD is the distribution coefficient of the adsorbate, qe and Ce are the equilibrium dye concentration on nanoporous Mg-AlPO4 and in the solution. R is the universal gas constant (8.314 J/mol K) and T is the temperature (K). Thermodynamic data are given in Table 3.The negative G values indicated that the adsorption of dyes on nanoporous Mg-AlPO4 was favourable. The enthalpy (H) values given in the Table 3 were more than 40 kJ/mol for both dyes indicated that the adsorption of dyes on Mg-AlPO4 was chemisorption and the positive value of enthalpy indicated that the adsorption process was endothermic. The positive value of S indicated that the degree of freedom was increased at the solid-liquid interface during the adsorption [12, 13].

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Table 3. Thermodynamic data for the adsorption of dyes on nanoporous Mg-AlPO4 Dyes

FY

IC

Temperature

G

H

S

(K)

(kJ/mol)

(kJ/mol)

(kJ/mol K)

303

-6.696

313

-8.246

323

-9.796

40.28

0.155

0.9583

333

-11.347

343

-12.897

303

-7.402

313

-8.991

323

-10.579

40.73

0.159

0.9908

333

-12.168

343

-13.757

R2

4. Conclusion

Nanoporous Mg-AlPO4 materials was synthesized and characterized by FT-IR, XRD and N2 sorption analysis. These characterization techniques proved the formation of Mg-AlPO4 as well as the formation of mesophase. Then the adsorption of organic dyes IC and FY was carried out at various adsorption experimental conditions. These studies proved that the Mg-AlPO4 was a better adsorbent for the adsorption of IC and FY. The thermodynamic study showed that the adsorption process is chemisorption, spontaneous and endothermic. References [1] A.R. Gregory, S. Elliot, P.Kluge, J. Appl. Toxicol. 1 (1991) 308–31. [2] G. Mckay, M.S. Otterburn, D.A. Aga, Water Air and Soil Poll.24 (1985) 307–322. [3] C. Kannan, N. Buvaneswari, T. Palvannan, Desalination. 249-3 (2009 ) 1132–1138. [4] Fatemeh Hosseini, SomeyehSadighian, Hassan Hosseini-Monfared, Niyaz Mohammad Mahmoodi, Desalin. water treat.57-51 (2016) 24378– 24386. [5] Niyaz Mohammad Mahmoodi, Javad Abdi, Zahra Afshar-Bakeshloo, Jafar Abdi, Desalin. water treat. 57-50 (2016) 24035–2446. [6] Soumitra Ghorai, Amit Kumar Sarkar, A.B. Panda, Sagar Pal, Bioresource Technol. 144 (2013) 485–491. [7] Li-Ngee Ho, Tasuku Ikegawa, Hiroyasu Nishiguchi, Katsutoshi Nagaoka, Yusaku Takita, Appl. Surf. Sci. 252-18 (2006) 6260–6268. [8] Na Gao, Jiyang Li, Jinsong Li, Jun Kong, Jihong Yu, Ruren Xu, Micropor.Mesopor.Mater. 174 (2013) 14–19. [9] Yanan Guo, Lang Shao, Xiaowei Song, Jiyang Li. Micropor.Mesopor.Mater. 165 (2013) 14–19. [10] Swapan K. Das, Manas K. Bhunia, Asim Bhaumik, Micropor.Mesopor.Mater. 155 (2012) 258–264. [11] Jian-Ming Lu, Koodali T. Ranjit, Pesak Rungrojchaipan, Larry Kevan, J. Phys. Chem. B. 109 (2005) 9284–9293. [12] Chellapandian Kannan, Thiravium Sundaram, Thayumanavan Palvannan, J. Hazard. Mater. 157 (2008) 137–145. [13] Muhammad Saif Ur Rehman, Ilgook Kim, Jong-In Han, Carbohyd. Polym. 90 (2012) 1314–1322.