Adsorption of As(III) versus As(V) from aqueous solutions by cerium-loaded volcanic rocks

• Published in: Environmental science and pollution research international Vol. 24; no. 25; pp. 20446 - 20458
• Main Authors: Asere, Tsegaye Girma, Verbeken, Kim, Tessema, Dejene A., Fufa, Fekadu, Stevens, Christian V., Du Laing, Gijs
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2017; Springer Nature B.V
• Subjects: Adsorbents; Adsorption; Aquatic Pollution; Arsenates - analysis; Arsenic; Arsenites - analysis; Atmospheric Protection/Air Quality Control/Air Pollution; Cerium; Cerium - chemistry; Contamination; Drinking water; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Health problems; Models, Theoretical; Oxidation-Reduction; pH effects; Pollutant removal; Pumice; Research Article; Silicates - chemistry; Solutions; Surface Properties; Volcanic Eruptions; Volcanic rocks; Waste Water Technology; Water Management; Water Pollutants, Chemical - analysis; Water Pollution Control; Water Purification - methods; Cerium; Arsenic; Adsorption; Pumice; Red scoria
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-017-9692-z

Contamination of drinking water with arsenic causes severe health problems in various world regions. Arsenic exists predominantly as As(III) and As(V) depending on the prevailing redox conditions of the environment. Most of the techniques developed for treating As(V) are not very effective for As(III), which is more toxic and mobile than As(V). In this study, novel cerium-loaded pumice (Ce-Pu) and red scoria (Ce-Rs) adsorbents were developed to remove both As(III) and As(V) ions from water. The Ce-Pu and Ce-Rs adsorbents were characterized using ICP-OES, EDX, and SEM. The experimental equilibrium sorption data fitted well Freundlich and Dubinin-Radushkevich (D-R) isotherms. The adsorption was very fast and reached an equilibrium within 2 h. Both Ce-Rs and Ce-Pu showed high As(III) and As(V) removal efficiency in a wide pH range between 3 and 9, which is an important asset for practical applications. The Ce-Pu and Ce-Rs adsorbents can be recycled and used up to three adsorption cycles without significant loss of their original efficiency. Accordingly, Ce-Pu and Ce-Rs seem to be suitable for removal of arsenic from aqueous systems.