US EPA

1597403 

Journal Article 

Removal of arsenic(III) from drinking water by adsorption with titanium and ferrous oxide nanoparticles 

Tang, Y-C; Huang, X-H; Wu, C-N 

2013 

Yes 

Asian Journal of Chemistry
ISSN: 0970-7077
EISSN: 0975-427X 

25 

5 

2491-2496 

WOS:000317245800029 

Adsorption isotherms and reaction kinetics of arsenic(III) removal from drinking water by adsorption with varying amount of titanium and ferrous oxide [namely Ti(OH)₄, TiO₂, Fe₃O₄ and Fe₂O₃] were evaluated in the present paper. Arsenic(III) can be average removed over 92% by these titanium or ferrous adsorbents within 2 h in near neutral solution (include in weak acid and weak alkaline solution). The reaction rate was speedy at initial stage of adsorption but the further time reaction rate was steeply decreased. The removal efficiency of arsenic(III) slightly increased with increasing solution pH to an adsorption maximum at around pH 8 but steep decreased with further increasing solution pH. Adsorption kinetics data were found to be best described by the modified pseudo-second-order kinetics model for titanium adsorbents [Ti(OH)₄ and TiO₂] but second-order kinetics model for ferrous oxide adsorbents (Fe₃O₄ and Fe₂O₃). Langmuir and Freundlich isotherms all fit the data but not very well. Maximum adsorption capacity (mg/g) calculated from the slope and the intercept of the graph of Dubinin-Radushkevich (D-R) isotherm were found to be 19.22 mg/g of Ti(OH)₄, 4.64 mg/g of TiO₂ and 66.42 mg/g of Fe₃O₄, respectively. Results of adsorption isotherms and reaction kinetics suggested the adsorption of arsenic(III) on titanium and ferrous oxide nano-particles were controlled by chemical process at low concentration but physical in high range. 

Arsenic(III); Drinking water; Adsorbent; Adsorption isotherms; Reaction kinetics