TY - JOUR

T1 - Modification of Natural Peat for Removal of Copper Ions from Aqueous Solutions

AU - Shvartseva, Olga

AU - Skripkina, Tatiana

AU - Gaskova, Olga

AU - Podgorbunskikh, Ekaterina

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation, project No 18‐77‐10029 (field, experimental, and analytical work, and mechanical and mechanochemical activation (treatment) of peat), and project No 20‐77‐10084 (physical and chemical properties of peat samples)., Design and adaptation of the potentiometric titration technique, determination of functional groups, structural, and morphological analysis of samples were supported by the Russian Science Foundation, project No 21‐13‐00046. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/7/1

Y1 - 2022/7/1

N2 - This study aimed at estimating peat adsorption properties for copper ion removal from aqueous solutions during peat modification. Two peat modifications have been studied using batch tests and quantitatively reproduced with instrumental analysis by using spectrometric, potentiometric, and thermodynamic modeling methods. The first variation—mechanical activation—was carried out in a planetary mill; for the second one—mechanochemical activation— dry sodium percarbonate (Na2CO3∙1.5H2O2) was added. The adsorption of copper ions was studied in the concentration range from 10–150 mg/L with an interaction time from 0.25–12 h. Both modifications led to significant changes in the interaction energy in the adsorption layer; thus, the acceptor properties of macromolecules were enhanced from natural peat to mechanically activated peat and mechanochemically activated peat. FTIR spectra, specific surface area characteristics, and sorption experiments show the predominantly chemical nature of copper sorption. Maximum adsorption capacity was determined to be 24.1, 42.1, and 16.0 mg/g for natural peat, mechanically activated peat, and mechanochemically activated peat, respectively. The example of peat mechanochemically oxidized with Na2CO3∙1.5H2O2 shows that the improvement in the physicochemical properties (CBET and specific surface area) plays a smaller role in the sorption capacity in relation to copper ions than the presence of phenolic and carboxyl groups, the content of which decreases during oxidation.

AB - This study aimed at estimating peat adsorption properties for copper ion removal from aqueous solutions during peat modification. Two peat modifications have been studied using batch tests and quantitatively reproduced with instrumental analysis by using spectrometric, potentiometric, and thermodynamic modeling methods. The first variation—mechanical activation—was carried out in a planetary mill; for the second one—mechanochemical activation— dry sodium percarbonate (Na2CO3∙1.5H2O2) was added. The adsorption of copper ions was studied in the concentration range from 10–150 mg/L with an interaction time from 0.25–12 h. Both modifications led to significant changes in the interaction energy in the adsorption layer; thus, the acceptor properties of macromolecules were enhanced from natural peat to mechanically activated peat and mechanochemically activated peat. FTIR spectra, specific surface area characteristics, and sorption experiments show the predominantly chemical nature of copper sorption. Maximum adsorption capacity was determined to be 24.1, 42.1, and 16.0 mg/g for natural peat, mechanically activated peat, and mechanochemically activated peat, respectively. The example of peat mechanochemically oxidized with Na2CO3∙1.5H2O2 shows that the improvement in the physicochemical properties (CBET and specific surface area) plays a smaller role in the sorption capacity in relation to copper ions than the presence of phenolic and carboxyl groups, the content of which decreases during oxidation.

KW - adsorption isotherm

KW - copper ions

KW - mechanical activation

KW - mechanochemical oxidation

KW - peat

KW - sorption

KW - thermodynamic modeling

UR - http://www.scopus.com/inward/record.url?scp=85133719158&partnerID=8YFLogxK

U2 - 10.3390/w14132114

DO - 10.3390/w14132114

M3 - Article

AN - SCOPUS:85133719158

VL - 14

JO - Water (Switzerland)

JF - Water (Switzerland)

SN - 2073-4441

IS - 13

M1 - 2114

ER -