COMPARATIVE EVALUATION OF THERMODYNAMIC AND SORPTION PARAMETERS OF ARSENIC AND MERCURY ION COMPLEXES
Keywords:
arsenic; mercury; complexation; sorption; UV–Vis; thermodynamics; KdAbstract
The thermodynamic and sorption parameters of As(III), As(V), and Hg(II) systems formed with an organic analytical reagent, R, and an R–sorbent phase were compared. Double-beam UV–Vis measurements were performed over 190–800 nm using 10 mm quartz cells; the thermodynamic series covered 293–313 K. At 293 K, ΔG° values for As(III)–R and Hg(II)–R were −18.40 and −24.10 kJ mol⁻¹ and became −21.70 and −27.35 kJ mol⁻¹ in the sorbent systems. Sorption capacity increased by 59.3% for As(III) and 39.5% for Hg(II). Hg(II)–R–sorbent gave the highest capacity (63.9 mg g⁻¹) and sorption degree (98.8%).
References
1. Alekseev V. G. Analytical Chemistry. Separation and Concentration Methods. Moscow: Khimiya, 2001. pp. 72–85.
2. Kabata-Pendias A. Trace Elements in Soils and Plants. 4th ed. Boca Raton: CRC Press, 2011. pp. 65–102. Marczenko Z. Separation and Spectrophotometric Determination of Elements. Chichester: Ellis Horwood, 1986. pp. 180–220.
3. Skoog D. A., Holler F. J., Crouch S. R. Principles of Instrumental Analysis. 6th ed. Belmont: Thomson Brooks/Cole, 2007. pp. 280–340.
4. World Health Organization (WHO). Guidelines for Drinking-water Quality. 4th ed. Geneva: WHO Press, 2017. pp. 15–
5. Zolotov Yu. A. Sorption Methods in Analytical Chemistry. Moscow: Nauka, 1998. pp. 110–145.
