Removal of Hexavalent Chromium from Water Using Cork-Based Biochars Obtained via Slow and Microwave Pyrolysis

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27350%2F25%3A10259164" target="_blank" >RIV/61989100:27350/25:10259164 - isvavai.cz</a>

Result on the web

<a href="https://www.mdpi.com/1420-3049/30/23/4501" target="_blank" >https://www.mdpi.com/1420-3049/30/23/4501</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/molecules30234501" target="_blank" >10.3390/molecules30234501</a>

Result language

angličtina

Original language name

Removal of Hexavalent Chromium from Water Using Cork-Based Biochars Obtained via Slow and Microwave Pyrolysis

Original language description

Cork-derived biochars produced by slow pyrolysis (C-SP) and microwave-assisted pyrolysis (C-MWP) were evaluated for the removal of hexavalent chromium [Cr(VI)] from aqueous solutions. The materials were characterized by proximate/elemental analysis, N&lt;inf&gt;2&lt;/inf&gt; physisorption (BET), thermogravimetry and FTIR. C-SP exhibited a higher specific surface area (174.5 m&lt;sup&gt;2&lt;/sup&gt;·g&lt;sup&gt;−1&lt;/sup&gt;), a larger micropore volume and stronger O–H/C–O surface signatures than C-MWP, which showed partial aromatization and less-developed texture. Batch equilibrium adsorption experiments at pH 2.0 with initial Cr(VI) concentrations of 5–150 mg·L&lt;sup&gt;−1&lt;/sup&gt; and kinetic experiments (c&lt;inf&gt;0&lt;/inf&gt; = 40 mg·L&lt;sup&gt;−1&lt;/sup&gt;) were analyzed by nonlinear fitting to standard isotherm and kinetic models. The experimentally observed maximum uptakes were qmax,obs = 32.7 mg·g&lt;sup&gt;−1&lt;/sup&gt; (C-SP) and 35.9 mg·g&lt;sup&gt;−1&lt;/sup&gt; (C-MWP) at pH 2.0. Under screening conditions (pH 1.1, 45 min), removals reached 72% (1.44 mg·g&lt;sup&gt;−1&lt;/sup&gt;) for C-SP and 87% (1.73 mg·g&lt;sup&gt;−1&lt;/sup&gt;) for C-MWP. The Freundlich model provided the best fit to the equilibrium data for C-SP, consistent with adsorption on an energetically heterogeneous surface, whereas for C-MWP the fitted isotherm models did not yield physically meaningful parameters. Kinetic modeling showed rapid initial uptake consistent with energetic heterogeneity of surface sites. However, kinetic fits alone do not determine whether uptake is dominated by physical adsorption, chemical binding or redox reactions; direct surface/speciation analyses would be required to substantiate mechanistic assignments.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10500 - Earth and related environmental sciences

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Molecules

ISSN

1420-3049

e-ISSN

1420-3049

Volume of the periodical

30

Issue of the periodical within the volume

23

Country of publishing house

CH - SWITZERLAND

Number of pages

20

Pages from-to

nestránkováno

UT code for WoS article

001635052800001

EID of the result in the Scopus database

2-s2.0-105024609574