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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10500 - Earth and related environmental sciences

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Molecules

ISSN

1420-3049

e-ISSN

1420-3049

Svazek periodika

30

Číslo periodika v rámci svazku

23

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

20

Strana od-do

nestránkováno

Kód UT WoS článku

001635052800001

EID výsledku v databázi Scopus

2-s2.0-105024609574