Studies Regarding As(V) Adsorption from Underground Water by Fe-XAD8-DEHPA Impregnated Resin. Equilibrium Sorption and Fixed-Bed Column Tests

Molecules

Mihaela Ciopec²  Adina Negrea²  Lavinia Lupa¹  Corneliu M. Davidesc²  Petru Negrea² 

[1] id="af1-molecules-19-16082">Faculty of Industrial Chemistry and Environmental Engineering Blvd., “Politehnica” University of Timisoara, Vasile Parvan No. 6, Timisoara 300223, Roman

关键词: arsenic removal;    Fe-XAD8-DEHPA;    underground water;    adsorption isotherm;    kinetics;    column study;   

DOI  :  10.3390/molecules191016082

来源: mdpi

【 摘 要 】

The characteristics of arsenic adsorption onto Fe-XAD8-DEHPA resin were studied on the laboratory scale using aqueous solutions and natural underground waters. Amberlite XAD8 resin was impregnated with di(2-ethylhexyl) phosphoric acid (DEHPA) via the dry method of impregnation. Fe(III) ions were loaded onto the impregnated resin by exploiting the high affinity of arsenic towards iron. The studies were conducted by both in contact and continuous modes. Kinetics data revealed that the removal of arsenic by Fe-XAD8-DEHPA resin is a pseudo-second-order reaction. The equilibrium data were modelled with Freundlich Langmuir and Dubinin Radushkevich (D-R) isotherms and it was found that the Freundlich model give the poorest correlation coefficient. The maximum adsorption capacity obtained from the Langmuir isotherm is 22.6 µg As(V)/g of Fe-XAD8-DEHPA resin. The mean free energy of adsorption was found in this study to be 7.2 kJ/mol and the ΔG° value negative (−9.2 kJ/mol). This indicates that the sorption process is exothermal, spontaneous and physical in nature. The studied Fe-XAD8-DEHPA resin showed excellent arsenic removal performance by sorption, both from synthetic solution and the natural water sample, and could be regenerated simply by using aqueous NaOH or HCl solutions.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.