Simple Alkali-Modified Persimmon Peel–Montmorillonite Composite Hydrochar for Rapid and Efficient Removal of Methylene Blue

Na Chai, Lihui Gao (), Shulei Li (), Zilong Ma, Lingni Li and Ming Hu
Additional contact information
Na Chai: School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116, China
Lihui Gao: School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
Shulei Li: National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China
Zilong Ma: National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, China
Lingni Li: School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116, China
Ming Hu: School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China

Sustainability, 2023, vol. 15, issue 15, 1-17

Abstract: Modified persimmon peel–montmorillonite composites (PMHC-KOH/NaHCO 3 ) for efficient and rapid removal of methylene blue (MB) were synthesized using hydrothermal carbonization and simple alkali impregnation. The surface properties and material compositions of the hydrochars were determined with SEM, zeta potential, and XRD, and the adsorption mechanism of MB on two modified hydrochars was analyzed with FTIR, XPS, and DFT calculation. The results showed that modified hydrochars with a rough surface structure and rich oxygen-containing groups exhibited a strong affinity for MB, and the adsorption capacity of PMHC-NaHCO 3 and PMHC-KOH for MB reached 121.28 mg/g and 278.41 mg/g, respectively, with PMHC-KOH achieving more rapid adsorption of MB, at a rate of 0.043 g/mg/min. After five adsorption/desorption cycles, the two modified hydrochars still maintained a high adsorption rate of MB (92.32%/98.43%). The excellent adsorption performance of the modified hydrochars was attributed to hydrogen bonding, π-π interaction, electrostatic attraction, and ion exchange. DFT calculations revealed that oxygen-containing groups of the modified hydrochars played an important role in the adsorption of MB and confirmed that electrostatic attraction, hydrogen bonding, and π-π interactions were the key forces for rapid and efficient adsorption of MB. The prepared adsorbents gave full play to the regenerative applicability of agricultural waste, the simple alkali impregnation method eliminated the need for the additional cost of pyrolysis and activation, and their application in MB adsorption realized the treatment of waste with waste.

Keywords: alkali-modified hydrochar; methylene blue; oxygen-containing functional groups; adsorption (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2023
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/15/15/11867/pdf (application/pdf)
https://www.mdpi.com/2071-1050/15/15/11867/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:15:y:2023:i:15:p:11867-:d:1208759

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().