Modeling Adsorption Kinetics of Magnesium and Phosphate Ions on Goethite by Empirical Equations

آب و خاک

Article 6, Volume 31, Issue 1 - Serial Number 51, March 2017, Pages 179-191   

Document Type: Research Article

DOI: 10.22067/jsw.v31i1.50556

Authors

Malihe Talebi Atouei^{* 1}; Rasoul Rahnemaie¹; Esmaiel Goli Kalanpa²; Mohammad Hossein davoodi

¹Tarbiat Modares University

²University of Mohaghegh Ardabili

Abstract

Introduction: Natural environments, including soils and sediments, are open and complex systems in which physico-chemical reactions are in semi equilibrium state. In these systems, bioavailability of plant nutrients, like phosphate, is influenced by environmental conditions and concentrations of other ions such as calcium and magnesium. Magnesium is a dominant cation in irrigation water and in the soil solution of calcareous soils. Recent evidences show relative increase in the concentration of magnesium in irrigation water. Because of the importance of chemical kinetics in controlling concentrations of these ions in the soil solution and for understanding their effects of adsorption kinetics of magnesium and phosphate ions, in this research, adsorption kinetics of these two ions on goethite is investigated as function of time and pH in single ion and binary ion systems. The experimental data are described by using the adsorption kinetics equations. These data are of the great importance in better understanding adsorption interactions and ion adsorption mechanism.With respect to the importance of these interactions from both economical and environmental point of view, in this research, the kinetics and thermodynamics of phosphate and Mg2adsorption interactions were investigated as function of pH on soil model mineral goethite in both single and binary ion systems.
Materials and Methods: Kinetics experiments were performed in the presence of 0.2 mM magnesium and 0.4 mM phosphate in 0.1 M NaCl background solution and 3 g L-1 goethite concentration as function of pH and time (1, 5, 14, 24, 48. 72 and 168 h) in single ion and binary ion systems. After reaction time, the suspensions were centrifuged and a sample of supernatant was taken for measuring ions equilibrium concentrations.Phosphate concentration was measured calorimetrically with the ammonium molybdate blue method by spectrophotometer (Jenway-6505 UV/Vis). Magnesium concentration was determined by atomic absorption spectrophotometer (AA-670Shimadzu AA/FE). The amounts of adsorbed ions were calculated from the difference of the initial and the equilibrium concentrations. The experimental data were described by using the several widely-used kinetic models. Models performance was evaluated based on their ability to describe experimental data and obtained values for coefficient of determination (R2) and standard error of the estimate (SE).
Results and Discussion: The results demonstrate that phosphate and magnesium adsorption on goethite reached equilibrium within the 24 h equilibration time. The equilibration time is, however, pH-dependent. No systematic differences are observed among time-dependent adsorption isotherms for phosphate at pHpHPZC. It seems that the effect of pH on kinetics of phosphate and magnesium adsorption is related to the mineral surface charge, which influences electrostatic interactions between the ions and the surface charges.thus electrostatic attractive and repulsive forces dominantly control the reaction. The equilibration time for phosphate and magnesium adsorption on goethite was calculated to be ≤1 h when electrostatic forces are attractive and approximately 24 h when electrostatic forces are repulsive. In binary ion systems, phosphate and magnesium enhanced the amount and accelerated the adsorption rate of each other. Adsorption of phosphate could reverse electrostatic forces from repulsive to attractive for the adsorption of magnesium and vice versa. Also, because of the smaller ionic radius of magnesium (0.065 nm) in comparison with phosphate (0.22 nm), reduction in equilibration time of magnesium adsorption in the presence of phosphate could be partly diffusion-controlled. Fitting different kinetic models on experimental data showed that pseudo-second order model can successfully describe phosphate and magnesium adsorption data in both single and binary ion systems with highest determination coefficient (R2~0.99) and lowest standard error of the estimate (SE

Keywords

adsorption; Electrostatic; Kinetic; Magnesium; phosphate

References

1- Abdollahpour, M., R. Rahnemaie, M. Talebi Atouei, and F. Aghamir. 2014. Investigating kaolinite charging behavior in NaCl electrolyte solution. Iranian Journal of Soil and Water Research (IJSWR). 45(1):95-101(in Persian).

2- Atkinson, R., A. Posner, and J. Quirk. 1967. Adsorption of potential-determining ions at the ferric oxide-aqueous electrolyte interface. Journal of physical chemistry. 71:550-558.

3- Azizian, S. 2004. Kinetic models of sorption: A theoretical analysis. Journal of Colloid and Interface Science. 276(1): 47-52.

4- Davoodi, M.H., R. Rahnemaie, and M.J. Malakouti. 2011. A Quantitative Analysis of Phosphate Adsorption on Iron Hydroxide Goethite (α-FeOOH): pH and Surface Area Effects. Journal of Water and Soil. 25(4):786-798 (In Persian with English abstract).

5-Dehghani, F. 2013. Effect of Calcium to Magnesium Ratio in Irrigation Water on the Soil Chemical Properties and Pistachio Growth in Saline Condition, in Ph. D. thesis. Soil science. Agriculture. Tarbiat Modares University. Teharn. Iran (In Persian with English abstract).

6- Dehghani, F., R. Rahnemaie, M.J. Malakouti, and S. Siadat. 2012. Investigation Ca:Mg ratio of irrigation water in Iran. Journal of Water Research in Agriculture 26(1):114-125 (in Persian).

7- Goli, E., R. Rahnemaie, T. Hiemstra, and M.J. Malakouti. 2011. The interaction of boron with goethite: Experiments and CD-MUSIC modeling. Chemosphere. 82(10):1475-1481.

8- Grossl, P.R. and D.L. Sparks. 1994. Rapid kinetics of Cu(II) adsorption/desorption on geothite. Environmental Science and Technology. 28(8):1422-1429.

9- Ho, Y.S. 2006.Review of second-order models for adsorption systems. Journal of Hazardous Materials. 136(3): 681-689

10- Jalali, M. and N. Ahmadi Mohammad Zinli. 2011. Kinetics of phosphorus release from calcareous soils under different land use in Iran. Journal of Plant Nutrition and Soil Science. 174(1):38-46.

11- Karaca, S., A. Gürses, M. Ejder, and M. Açikyildiz. 2004. Kinetic modeling of liquid-phase adsorption of phosphate on dolomite. Journal of Colloid and Interface Science. 277(2):257-263.

12- Karimov, A., M. Qadir, A. Noble, F. Vyshpolsky, et al. 2009. Development of Magnesium-Dominant Soils Under Irrigated Agriculture in Southern Kazakhstan. Pedosphere. 19(3):331-343.

13- Katz, L.E., L.J. Criscenti, C.C. Chen, J.P. Larentzos, et al. 2013. Temperature effects on alkaline earth metal ions adsorption on gibbsite: Approaches from macroscopic sorption experiments and molecular dynamics simulations. Journal of Colloid and Interface Science. 399:68-76.

14- Luengo, C., M. Brigante, and M. Avena. 2007. Adsorption kinetics of phosphate and arsenate on goethite. A comparative study. Journal of Colloid and Interface Science. 311(2):354-360.

15- Neupane, G., R.J. Donahoe, and Y. Arai. 2014. Kinetics of competitive adsorption/desorption of arsenate and phosphate at the ferrihydrite-water interface. Chemical Geology. 368:31-38.

16- Qadir, M., A.D. Noble, A.S. Qureshi, R.K. Gupta, et al. 2009. Salt-induced land and water degradation in the Aral Sea basin: A challenge to sustainable agriculture in Central Asia. Natural Resources Forum. 33(2):134-149.

17- Qiu, H. 2009. Critical review in adsorption kinetic models. Journal of Zhejiang University: Science A. 10(5): 716-724.19-

18. Rahnemaie, R. 2005. Ion adsorption modeling as a tool to characterize metal (hydr)oxcide behavior in soil. Ph. D. Thesis. Wageningen, The Netherlands.

19- Rahnemaie, R., T. Hiemstra, and W.H. Van Riemsdijk. 2006. A new surface structural approach to ion adsorption: Tracing the location of electrolyte ions. Journal of Colloid and Interface Science. 293(2):312-321.

20- Sparks, D.L. 1998. Soil physical chemistry. CRC press.

21- Strauss, R., G.W. Brümmer, and N.J. Barrow. 1997. Effects of crystallinity of goethite: II. Rates of sorption and desorption of phosphate. European Journal of Soil Science. 48(1):101-114.

22- Tejedor-Tejedor, M.I. and M.A. Anderson. 1990. Protonation of Phosphate on the Surface of Goethite as Studied by Cir-Ftir and Electrophoretic Mobility. Langmuir. 6(3): 602-611.

23- Vyshpolsky, F., M. Qadir, A. Karimov, K. Mukhamedjanov, et al. 2008. Enhancing the productivity of high-magnesium soil and water resources in Central Asia through the application of phosphogypsum. Land Degradation and Development. 19(1):45-56.

24- Wang, K. and B. Xing. 2002. Adsorption and desorption of cadmium by goethite pretreated with phosphate. Chemosphere. 48(7):665-670.

25- Yoon, S.Y., C.G. Lee, J.A. Park, J.H. Kim, et al. 2014. Kinetic, equilibrium and thermodynamic studies for phosphate adsorption to magnetic iron oxide nanoparticles. Chemical Engineering Journal. 236:341-347.

26- Zhang, J. and R. Stanforth. 2005. Slow adsorption reaction between arsenic species and goethite (α-FeOOH): Diffusion or heterogeneous surface reaction control. Langmuir. 21(7):2895-2901.

27- Zhang, X.C. and L.D. Norton. 2002. Effect of exchangeable Mg on saturated hydraulic conductivity, disaggregation and clay dispersion of disturbed soils. Journal of Hydrology. 260(1-4):194-205.