Wydział Chemii

Agnieszka Medyńska-Juraszek

Maria Luisa Álvarez

Andrzej Białowiec

Maria Jerzykiewicz

2021

Materials

14

4714/1-4714/19

10.3390/ma14164714

Naukowa

Angielski

Artykuł

Excessive amounts of sodium cations (Na+) in water is an important limiting factor to
reuse poor quality water in agriculture or industry, and recently, much attention has been paid to
developing cost-effective and easily available water desalination technology that is not limited to
natural resources. Biochar seems to be a promising solution for reducing high loads of inorganic
contaminant from water and soil solution, and due to the high availability of biomass in agriculture
and forestry, its production for these purposes may become beneficial. In the present research,
wheat straw, sunflower husk, and pine-chip biochars produced at 250, 450 and 550 C under simple
torrefaction/pyrolysis conditions were chemically modified with ethanol or HCl to determine the
effect of these activations on Na sorption capacity from aqueous solution. Biochar sorption property
measurements, such as specific surface area, cation exchange capacity, content of base cations
in exchangeable forms, and structural changes of biochar surface, were performed by FTIR and
EPR spectrometry to study the effect of material chemical activation. The sorption capacity of
biochars and activated carbons was investigated by performing batch sorption experiments, and
adsorption isotherms were tested with Langmuir’s and Freundlich’s models. The results showed
that biochar activation had significant effects on the sorption characteristics of Na+, increasing its
capacity (even 10-folds) and inducing the mechanism of ion exchange between biochar and saline
solution, especially when ethanol activation was applied. The findings of this study show that biochar
produced through torrefaction with ethanol activation requires lower energy demand and carbon
footprint and, therefore, is a promising method for studying material applications for environmental
and industrial purposes.

biochar, modification, sodium, sorbent, saline water, soil

CC-BY

https://doi.org/10.3390/ma14164714

http://www.mdpi.com/journal/metals