Removal of Rhodamine B from aqueous solutions and wastewater by walnut shells: kinetics, equilibrium and thermodynamics studies

Abstract

An adsorption study of Rhodamine B (RB) dye from aqueous solutions was carried out using walnut shells pretreated by different methods. In addition to the effects of the pretreatment, the effects of various parameters like pH, adsorbent dose, contact time, initial dye concentration and temperature on the adsorption of RB was studied. The adsorption process was highly pH dependent and a maximum adsorption was achieved at pH 3.0. The best fit for the rates of dye adsorption was a pseudo-second-order kinetic model with good correlation coefficients (R²>0.99). Langmuir isotherms were used to determine that the maximum loading capacity of the different walnut shells and the RB capacities ranged from 1.451–2.292 mg·g^-1. The dye adsorption was also evaluated thermodynamically. Positive standard enthalpy (∆H°) values were obtained indicating that the RB adsorption process is endothermic as well as ∆G° and ∆S° values showed that adsorption process is spontaneous with an increased randomness at the solid-liquid interface. Desorption studies were carried out to explore the feasibility of regenerating the used walnut shells and it was found that 97.71%–99.17% of the retained RB was recovered with 0.1 mol∙L^-1 NaOH solution. The walnut shells were also successfully used to remove RB from industrial effluents.

Key words： Rhodamine B; walnut shell adsorption; kinetics; isotherms; regeneration

References

1 Laasri L, Elamrani M K, Cherkaoui O. Removal of two cationic dyes from a textile effluent by filtration-adsorption on wood sawdust. Environmental Science and Pollution Research International, 2007, 14(4): 237-240

2 Hamdaoui O. Dynamic sorption of methylene blue by cedar sawdust and crushed brick in fixed bed columns. Journal of Hazardous Materials, 2006, 38(2): 293-303

3 Hameed B H, Din A T M, Ahmad A L. Adsorption of methylene blue onto bamboo based activated carbon: Kinetics and equilibrium studies. Journal of Hazardous Materials, 2007, 14(3): 819-825

4 Senturk H B, Ozdes D, Duran C. Biosorption of Rhodamine 6G from aqueous solutions onto almond shell (Prunus dulcis) as a low cost biosorbent. Desalination, 2010, 252(1-3): 81-87

5 Robinson T, McMullan G, Marchant R, Poonam N. Remediation of dyes in textile effluent: A critical review on current treatment technologies with a proposed alternative. Bioresource Technology, 2001, 77(3): 247-255

6 Figueiredo S A, Boaventura R A, Loureiro J M. Color removal with natural adsorbents: Modeling, simulation and experimental. Separation and Purification Technology, 2000, 20(1): 129-141

7 Vilar V J P, Botelho C M S, Boaventura R A R. Methylene blue adsorption by algal biomass based materials: Biosorbents characterization and process behavior. Journal of Hazardous Materials, 2007, 147(1-2): 120-132

8 Demirbas E, Kobya M, Sulak M T. Adsorption kinetics of a basic dye from aqueous solutions onto apricot stone activated carbon. Bioresource Technology, 2008, 99(13): 5368-5373

9 Guo Y, Zhao J, Zhang H, Yang S, Qi J, Wang Z, Xu H. Use of rice husk-based porous carbon for adsorption of Rhodamine B from aqueous solutions. Dyes and Pigments, 2005, 66(2): 123-128

10 Khattri S D, Singh M K. Color removal from synthetic dye wastewater using a biosorbent. Water, Air, and Soil Pollution, 2000, 120(3/4): 283-294

11 McKay G, Porter J F, Prasad G R. The removal of basic dyes aqueous solution by adsorption on low-cost materials. Water, Air, and Soil Pollution, 1999, 114(3/4): 423-438

12 Mittal A, Krishnan L, Gupta V K. Removal and recovery of malachite green from wastewater using an agricultural waste material, de-oiled soya. Separation and Purification Technology, 2005, 43(2): 125-133

13 Hameed B H, Hakimi H. Utilization of durian (Durio zibethinus Murray) peel as low cost sorbent for the removal of acid dye from aqueous solutions. Biochemical Engineering Journal, 2008, 39(2): 338-343

14 Ahmad A A, Hameed B H, Aziz N. Adsorption of direct dye on palm ash: Kinetic and equilibrium modeling. Journal of Hazardous Materials, 2007, 141(1): 70-76

15 Hameed B H, El-Khaiary M I. Sorption kinetics and isotherm studies of a cationic dye using agricultural waste: Broad bean peels. Journal of Hazardous Materials, 2008, 154(1-3): 639-648

16 Serencam H, Gundogdu A, Uygur Y, Kemer B, Bulut V N, Duran C, Soylak M, Tufekci M. Removal of cadmium from aqueous solution by Nordmann fir (Abies nordmanniana (Stev.) Spach. Subsp. nordmanniana) leaves. Bioresource Technology, 2008, 99(6): 1992-2000

17 Hasar H. Adsorption of nickel (II) from aqueous solution onto activated carbon prepared from almond husk. Journal of Hazardous Materials, 2003, 97(1-3): 49-57

18 Pehlivan E, Altun T. Bioadsorption of chromium(VI) ion from aqueous solutions using walnut, hazelnut and almond shell. Journal of Hazardous Materials, 2008, 155(1-2): 378-384

19 Altun T, Pehlivan E. Removal of Cr(VI) from aqueous solutions by modified walnut shells. Food Chemistry, 2012, 132(2): 693-700

20 Al-Rashed S M, Al-Gaid A A. Kinetic and thermodynamic studies on the adsorption behavior of Rhodamine B dye on Duolite C-20 resin. Journal of Saudi Chemical Society, 2012, 16(2): 209-215

21 Wang J, Wang D, Zhang G, Guo Y, Liu J. Adsorption of Rhodamine B from aqueous solution onto heat-activated sepiolite. Wuhan University Journal of Natural Sciences, 2013, 18(3): 219-225

22 Rasalingam S, Peng R, Koodali R T. An investigation into the effect of porosities on the adsorption of Rhodamine B using titania-silica mixed oxide xerogels. Journal of Environmental Management, 2013, 128: 530-539

23 Britton H T S. “Hydrogen Ions” Monographs on Applied Chemistry. New York, 1943, 313

24 Anandkumar J, Mandal B. Adsorption of chromium (VI) and Rhodamine B by surface modified tannery waste: Kinetic, mechanistic and thermodynamic studies. Journal of Hazardous Materials, 2011, 186(2-3): 1088-1096

25 Selvan P P. Preethi Sm, Basakaralingan P, Thinakaran N, Sivasamy A, Sivanesan S. Removal of Rhodamine B from aqueous solution by adsorption onto sodium montmorillonite. Journal of Hazardous Materials, 2008, 155: 39-44

26 Kyazs G Z, Lazaridis N K, Mitropoulos A C. Removal of dyes from aqueous solutions with untreated coffee residues as potential low-cost adsorbents: Equilibrium, reuse and thermodynamic approach. Chemical Engineering Journal, 2012, 189-190(1): 148-159

27 Noreen S, Bhatti H N, Nausheen S, Sadaf S, Ashfaq M. Batch and fixed bed adsorption study for the removal of Drimarine Black CL-B dye from aqueous solution using a lignocellulosic waste: A cost affective adsorbent. Industrial Crops and Products, 2013, 50(10): 568-579