Steam activation of biochars facilitates kinetics and pH-resilience of sulfamethazine sorption
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Sulfamethazine (SMT) is increasingly detected in environmental matrices due to its versatile use as antibiotics. We aimed to investigate the benefits and roles of steam activation of biochars with respect to SMT sorption kinetics and equilibrium sorption.
Materials and methods
Biochars were produced from burcucumber plant and tea waste using a pyrolyzer at a temperature of 700 °C for 2 h. The biochar samples were treated with 5 mL min−1 of steam for an additional 45 min for post-synthesis steam activation. The SMT sorption on the unmodified and steam activated biochars were compared.
Results and discussion
The time taken to reach equilibrium was significantly less for steam activated biochars (∼4 h) than non-activated biochars (>24 h). Up to 98 % of SMT could be removed from aqueous solutions by steam activated biochars. The sorption kinetic behaviors were well described by the pseudo-second model and SMT sorption rates of steam activated biochars (k 2 ∼ 1.11–1.57 mg g−1 min−1) were significantly higher than that of the unmodified biochars (k 2 ∼ 0.04–0.11 mg g−1 min−1) because of increased availability of accessible porous structure with averagely larger pore diameters. Moreover, the equilibrium sorption on the unmodified biochars was significantly influenced by increasing solution pH (∼30–50 % reduction) because of speciation change of SMT, whereas steam activated biochars manifested much stronger sorption resilience against pH variation (∼2–4 % reduction only) because the enhanced porosity offset the effect of unfavorable electrostatic repulsion.
The observed features of steam activated biochars would render their applications more versatile and reliable in field throughout changeable environmental conditions.
KeywordsAntibiotics Charcoal Designer biochar Engineered biochar Sorption kinetics
This study was supported by the National Research Foundation of Korea (NRF-2015R1A2A2A11001432).
- Benjamin MM (2002) Adsorption reactions. Water chemistry. McGraw-Hill, New York, pp 550–627Google Scholar
- Boxall ABA, Fogg LA, Blackwell PA, Blackwell P, Kay P, Pemberton EJ, Croxford A (2004) Veterinary medicines in the environment. Rev Environ Contam Toxicol, Springer, New York, pp 1–91Google Scholar
- Chia CH, Downie A, Munroe P (2015) Characteristics of biochar: physical and structural properties. In: Lehmann J, Joseph S (eds) Biochar for environmental management. Earthscan, London, pp 89–111Google Scholar
- Lagergren S (1898) Zurtheorie der sogenannten adsorption gelosterstoffe. Kungliga Svenska Vetenskapsakademiens Handlingar 24:1–39Google Scholar
- Lehmann J, Joseph S (2009) Biochar for environmental management: science and technology. Earthscan, LondonGoogle Scholar
- Lima IM, Boateng AA, Klasson KT (2010) Physicochemical and adsorptive properties of fast-pyrolysis bio-chars and their steam activated counterparts. J Chem Technol Biotechnol 85:1515–1521Google Scholar
- Margalida A, Bogliani G, Bowden CGR, Donázar JA, Genero F, Gilbert M, Karesh WB, Kock R, Lubroth J, Manteca X, Naidoo V, Neimanis A, Sánchez-Zapata JA, Taggart MA, Vaarten J, Yon L, Kuiken T, Green RE (2014) One health approach to use of veterinary pharmaceuticals. Science 346:1296–1298CrossRefGoogle Scholar
- Novak JM, Lima I, Xing B, Gaskin JW, Steiner C, Das KC, Ahmedna M, Rehrah D, Watts DW, Busscher WJ, Harry S (2009) Characterization of designer biochar produced at different temperatures and their effects on a loamy sand. Ann Environ Sci 3:195–206Google Scholar
- Sparks DL (1999) Soil physical chemistry, 2nd edn. CRC Press, New YorkGoogle Scholar
- Sposito G (2004) The surface chemistry of natural particles. Oxford University Press, New YorkGoogle Scholar