resumo
Layered double hydroxides (LDHs) are regarded as potential adsorbents for water treatment from a wide range of pollutants. However, there are only a few studies concerning application of LDHs for elimination of microorganisms from aquatic systems. In this work, experiments were conducted to investigate the efficiency of commercial synthetic hydrotalcite Mg6Al2(CO3)(OH)16 center dot 4H2O as an adsorbent for water purification from fecal indicator bacteria Escherichia coli BIM B-378 and Enterococcus faecalis BIM B-1530. Our findings indicate that exposure for 4 h to hydrotalcite (5 g/L) in suspension resulted in the removal of about 40% of coliforms and 25% of enterococci from water, at a high bacterial load (2x10(10) CFU/L), and the removal efficiency of E. coli and E. faecalis did not significantly change when both bacteria were present in water. In addition, the percentage of removed bacteria increased with increasing of hydrotalcite concentration in the suspension (0.5 to 10 g/L), contact time (1-7 h) and decrease of pH (5.5), and decreased at low incubation temperature (16 degrees C). Finally, hydrotalcite did not exhibit bactericidal activity and retention of bacteria was found to be reversible. Therefore, our findings suggest that commercial synthetic hydrotalcite could be potentially used in technologies of water treatment from bacterial contamination.
palavras-chave
LAYERED DOUBLE HYDROXIDES; SURFACE-CHARGE; PH; ADSORPTION; TRANSPORT; DYE; AL
categoria
Engineering; Environmental Sciences & Ecology
autores
Sidarenka, AV; Leanovich, SI; Kalamiyets, EI; Vieira, DEL; Cardoso, JPV; Tedim, J; Salak, AN
nossos autores
Andrei Salak
Investigador Principal
João Tedim
Professor associadoProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
D.E.L.V and J.P.V.C acknowledge the financial support of FCT the Portuguese Foundation for Science and Technology through the individual PhD grants PD/BD/143033/2018 and SFRH/BD/145281/2019, respectively. A.N.S. acknowledges the financial support of national funds (OE) through FCT -Portugal in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. The research done in University of Aveiro was supported by project COAT4LIFE. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 101007430. The authors from University of Aveiro acknowledge the support from the project CICECO -Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC).