Adsorption of arsenic from water and its recovery as a highly active photocatalyst
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The contamination of water with arsenic has aroused concern around the world due to its toxic effects. Thus, the development of low-cost technologies for treating water contaminated with toxic metals is highly advisable. Adsorption is an attractive technology for purification of contaminated water, but it only transfers the contaminant from water to the solid adsorbent, which provokes another problem related to solid residue disposal. In this work, we developed a sustainable method for purifying water contaminated with arsenic by using δ-FeOOH nanoparticles. The adsorption capacities of nanomaterial for As3+ and As5+ species were 40 and 41 mg g−1, respectively, and were highly efficient to purify arsenic-contaminated water from a Brazilian river. The concentration of arsenic in water was close to zero after the water treatment by δ-FeOOH. Once the arsenic is adsorbed, it can be recovered by treatment with NaOH solutions. Approximately 85 % of the total adsorbed arsenic could be recovered and used as a precursor to produce useful material (Ag3AsO4) with excellent photocatalytic activity. It was active under visible light and had a high recyclability for oxidation of rhodamine B. Finally, the simple method described is promising to design sustainable process of environmental remediation with minimum residue generation.
KeywordsArsenate Contaminated water Remediation Adsorption Photocatalyst Iron oxide
The authors are grateful to CNPq, Fapemig, Rede Mineira de Química (RQ-MG), Fapesp, and CAPES for the financial support and fellowships.
- Andrade RP, Santana Filho S, De Mello JWV, De Figueiredo BR, Dussin TM (2008) Arsenic mobilization from sulfidic materials from gold mines in Minas Gerais State. Quim Nov. 31(5):1127–1130Google Scholar
- Aredes S, Klein B, Pawlik M (2012) The removal of arsenic from water using natural iron oxide minerals. J Clean Prod 29–30, 208–213Google Scholar
- Companhia de Tecnologia e Saneamento Ambiental (2011) Coleta de amostras de águas de rios. Companhia Ambiental do Estado de São Paulo, São Paulo, Brazil. Disponible: www.cetesb.sp.gov.br. Accessed May 2015
- Lagergren S (1898) About the theory of so-called adsorption of soluble substance. Kungliga Svenska Vetenskapsakademiens Handlingar 24:1–39Google Scholar
- Pinto, I.S.X., Pacheco, P.H.V.V., Coelho, J.V., Lorençon, E., Ardisson, J.D., Fabris, J.D., de Souza, P.P., Krambrock, K.W.H., Oliveira, L.C.A. and Pereira, M.C. 2012 Nanostructured δ-FeOOH: an efficient Fenton-like catalyst for the oxidation of organics in water. Appl Catal B: Environ 119–120, 175–182Google Scholar
- Rocha TDS, Nascimento ES, Da Silva AC, Oliveira HDS, Garcia EM, De Oliveira LCA, Monteiro DS, Rodriguez M, Pereira MC (2013) Enhanced photocatalytic hydrogen generation from water by Ni(OH)2 loaded on Ni-doped δ-FeOOH nanoparticles obtained by one-step synthesis. RSC Adv 3(43):20308–20314CrossRefGoogle Scholar
- Weber WJ, Morris JC (1963) Kinetics of adsorption of carbon from solutions. J Sanit Eng Div 89(2):31–60Google Scholar