Engineered biochar as a tool for nitrogen pollutants removal:

Author(s)
Eva Viglašová, Michal Galamboš, David Diviš, Zuzana Danková, Martin Daňo, Lukáš Krivosudský, Christian Lengauer, Marek Matík, Jaroslav Briančin, Gerhard Soja
Abstract

In this study, engineered (chemically modified) biochars (pyrolyzed bamboo biomass) were used for the removal of oxidized and reduced nitrogen species from an aqueous solution. The physico-chemical properties of the prepared materials, such as surface functional groups, elemental composition, morphology, and specific surface area were investigated. The biochar surfaces were covered with Mg and Fe particles. The particles containing Mg and Fe species were observed in the form of nanoflakes within the biochar matrix. The efficiency of nitrate and ammonium removal was examined by sorption studies. The experimental data were fitted with sorption isotherms (Langmuir, Freundlich, and Dubinin-Raduskievich) and with kinetic models. The obtained data presented a higher sorption capacity for nitrate removal in the case of the engineered Fe-biochar and the engineered Mg-biochar compared to unmodified bamboo-based biochar. The maximum sorption capacity of modified samples decreased in the order Fe-biochar (Qe = 10.35 mg g-1), Mg-biochar (Qe = 9.13 mg g-1), and the lowest capacity was found in the unmodified biochar (Qe = 4.41 mg g-1). In the case of ammonium removal, unmodified biochar with maximum sorption capacity (Qe = 12.60 mg g-1), was more efficient than Fe-(Qe = 5.66 mg g-1), and Mg-engineered biochars (Qe = 3.23 mg g-1). The pseudosecond- order kinetic model and Langmuir isotherm model proved to be the most appropriate for the experimental sorption data. In addition, engineered Fe-biochar presented magnetic properties due to the presence of Fe2O3 and therefore, may be easily separated from the reaction mixtures.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
Comenius University Bratislava, Czech Technical University in Prague (CTU), State Geological Institute of Dionyz Stur, University of Natural Resources and Life Sciences, Austrian Institute of Technology, Slovak Academy of Sciences (SAS), University of Vienna
Journal
Desalination and Water Treatment
Volume
191
Pages
318-331
No. of pages
14
ISSN
1944-3994
DOI
https://doi.org/10.5004/dwt.2020.25750
Publication date
07-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
104011 Materials chemistry, 105113 Crystallography
Keywords
ASJC Scopus subject areas
Water Science and Technology, Pollution, Ocean Engineering
Portal url
https://ucrisportal.univie.ac.at/en/publications/a6c48184-a7c4-4fb9-a317-aa869c3c7be7