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| Titel |
Synthesis of magnetic adsorbents for the removal of Hg(II) from aqueous solutions |
| VerfasserIn |
Ekavi C. Isari, Hrissi K. Karapanagioti, Ioannis D. Manariotis, David Werner |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250093823
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| Publikation (Nr.) |
 EGU/EGU2014-8923.pdf |
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| Zusammenfassung |
| Activated carbon (AC) is known to adsorb aqueous Hg (II). AC acts as a strong binding agent
that lowers the pollutant concentration and thus, its toxicity. Another promising material in
environmental applications such as metal removal is biochar (BC), which is obtained from the
incomplete combustion of carbon-rich biomass under oxygen-limited conditions. A draw
back of this method is that although the pollutant will be non- bioavailable for many
years into sorbents, it actually remains into the system. The objective of this study
was (a) to synthesize a magnetic powdered activated carbon (AC/Fe) and magnetic
powdered biochar (BC/Fe) produced from commercial AC (AC1 and AC2), and biochar
respectively, and (b) to evaluate the potential use of AC/Fe and BC/Fe to remove
aqueous Hg(II) while being magnetically recoverable. The biochar was produced
from olive seeds. The surface area, the pore volume, and the average pore size of
each sorbent were determined using gas (N2) adsorption-desorption cycles and
the Brunauer, Emmett, and Teller (BET) equation. Isotherms with 30 adsorption
and 20 desorption points were conducted at liquid nitrogen temperature (77K).
Open surface area and micropore volume were determined using t-plot method and
Harkins & Jura equation. Surface area measurements resulted in values of 640
and 790 m2/g for AC1 and AC2 samples and 433 and 517 m2/g for AC1/Fe and
AC2/Fe samples, respectively. The surface area BC and BC/Fe was 390 m2/g and 320
m2/g, respectively. Batch experiments with all sorbents were conducted at room
temperature (25oC), at pH 5, and various initial Hg(II) concentrations, in order to
compare the sorption properties of the materials. Based on the isotherm data, AC/Fe
and BC/Fe seem to be effective sorbents demonstrating lower sorption capacities
ranging from 50 to 75% of those of the initial materials. All these properties point to
promising materials that can be effectively used for in-situ environmental remediation. |
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