Author(s)

MIHAELA CIOPEC, IOSIF HULKA, NARCIS DUŢEANU, ADINA NEGREA, OANA GRAD, PETRU NEGREA, VASILE MINZATU, CRISTINA ARDEAN

Abstract

Water represents an essential resource for earth life and for all-natural processes. It is well known that in all developing countries the underground water resource represents the main source of drinking water and its contamination with arsenic presents a real problem. Thus, we have developed a new adsorbent based on cellulose doped with crown ethers (dibenzo-18-crown-6) functionalized with iron ions and used for the removal of arsenic from water. Usage of such extractants involves only a small amount of crown ether indicating higher efficiency of produced material, and, in order to improve the adsorbent properties and selectivity for arsenic removal, the modified cellulose was functionalized with iron ions. The new obtained adsorbent material was characterized by using energy dispersive X-ray analysis, scanning electron microscopy and Fourier Transform Infrared Spectroscopy. In order to investigate the adsorbent properties for arsenic removal equilibrium, kinetic and thermodynamic studies were performed. Arsenic adsorption from water onto a new adsorbent was studied under different experimental conditions such as reaction times, initial arsenic concentration and temperature. Obtained results show that the new produce adsorbent has a higher efficiency for arsenic removal, leading to lower residual concentration (under 10 μg As L^-1 – value accepted by WHO).

Keywords

arsenic, crown ethers, iron ions, water, adsorption