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Ma S, Wei S, Li S, Wei W, Huang Y. Facile activation of natural calcium-rich sepiolite with oxalic acid for selective Pb(II) removal: Highly-efficient performance, mechanisms and site energy distribution. CHEMOSPHERE 2023; 342:140201. [PMID: 37722536 DOI: 10.1016/j.chemosphere.2023.140201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/20/2023]
Abstract
The design and development of adsorbents with high efficiency, selectivity, and economy for Pb(II) are essential to environmental governance and ecological safety. Herein, an oxalic acid (OA) activated natural sepiolite (nSEP) composite for highly efficient Pb(II) removal was prepared by a facile impregnation strategy. The OA activated nSEP nanocomposite (OA-nSEP) was characterized by various instrumental techniques and its adsorption performance towards Pb(II) was further evaluated through a series of static and dynamic experiments under various environmental conditions. Results revealed that OA reacted with the calcium impurities in nSEP to form calcium oxalate, causing mesoporous structure and larger specific surface area of OA-nSEP. The obtained OA-nSEP possessed super high Pb(II) adsorption capacities (858.4-1252 mg/g), which were much higher than that of most modified clays or conventional materials. The average adsorption site energy and the standard deviation of the site energy distribution were analyzed to investigate the strength of Pb(II) binding onto OA-nSEP and the adsorption site heterogeneity. Mechanism studies confirmed that oxalate groups exerted a primary role in the adsorption process. X-ray diffraction and X-ray photoelectron spectrometry (XPS) unveiled that the coordination of oxalate with Pb(II) and precipitation of lead oxalate was responsible for the high efficiency and selectivity. Distinguishing feature of high adsorption capacity, specific selective adsorption, abundant availability, and splendid reusability make the OA-nSEP a promising candidate for eliminating Pb(II) in practical scenarios.
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Affiliation(s)
- Shoucheng Ma
- School of Environment, Jiangsu Engineering Lab of Water and Soil Eco-remediation, Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing Normal University, Nanjing, 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, 210023, China
| | - Song Wei
- Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, 541004, China
| | - Siyuan Li
- School of Environment, Jiangsu Engineering Lab of Water and Soil Eco-remediation, Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing Normal University, Nanjing, 210023, China
| | - Wei Wei
- School of Environment, Jiangsu Engineering Lab of Water and Soil Eco-remediation, Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing Normal University, Nanjing, 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, 210023, China.
| | - Yao Huang
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Academy of Sciences, Guangzhou, 510650, China.
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Nkwoada A, Onyedika G, Oguzie E, Ogwuegbu M. Thermodynamics, Kinetics, and Reaction Mechanism of Kaolin Adsorption/Photocatalysis of Hazardous Cationic and Anionic Dyes. CHEMISTRY AFRICA 2022. [DOI: 10.1007/s42250-022-00426-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Nyankson E, Aboagye SO, Efavi JK, Agyei-Tuffour B, Paemka L, Asimeng BO, Balapangu S, Arthur PK, Tiburu EK. Chitosan-Coated Halloysite Nanotubes As Vehicle for Controlled Drug Delivery to MCF-7 Cancer Cells In Vitro. MATERIALS 2021; 14:ma14112837. [PMID: 34073202 PMCID: PMC8198553 DOI: 10.3390/ma14112837] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 01/08/2023]
Abstract
The aim of the work is to improve the release properties of curcumin onto human breast cancer cell lines using coated halloysite nanotubes (HNTs) with chitosan as a polycation. A loading efficiency of 70.2% (w/w) was attained for loading 4.9 mg of the drug into 0.204 g bed volume of HNTs using the vacuum suction method. Results acquired from Brunauer-Emmett-Teller (BET), Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron spectroscopy (SEM), zeta potential, and thermogravimetric analysis (TGA) indicated the presence of the drug and the biopolymer in and around the nanotubes. The release properties of drug-loaded HNTs (DLHNTs) and chitosan-coated drug-loaded HNTs (DLHNTs-CH) were evaluated. The release percentages of DLHNTs and DLHNTs-CH after 6 h were 50.7 and 37%, respectively. Based on the correlation coefficients obtained by fitting the release nature of curcumin from the two samples, the Korsmeyer-Peppas model was found to be the best-fitted model. In vitro cell viability studies were carried out on the human breast cancer cell line MCF-7, using the MTT and trypan blue exclusion assays. Prior to the Trypan blue assay, the IC50 of curcumin was determined to be ~30 µM. After 24 h of incubation, the recorded cell viability values were 94, 68, 57, and 51% for HNTs, DLHNTs-CH, DLHNTs, and curcumin, respectively. In comparison to the release studies, it could be deducted that sustained lethal doses of curcumin were released from the DLHNTs-CH within the same time. It is concluded from this work that the "burst release" of naked drugs could be slowly administered using chitosan-coated HNTs as potential drug carriers.
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Affiliation(s)
- Emmanuel Nyankson
- Department of Materials Science and Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana; (E.N.); (S.O.A.); (J.K.E.); (B.A.-T.)
| | - Shadrack O. Aboagye
- Department of Materials Science and Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana; (E.N.); (S.O.A.); (J.K.E.); (B.A.-T.)
| | - Johnson Kwame Efavi
- Department of Materials Science and Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana; (E.N.); (S.O.A.); (J.K.E.); (B.A.-T.)
| | - Benjamin Agyei-Tuffour
- Department of Materials Science and Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana; (E.N.); (S.O.A.); (J.K.E.); (B.A.-T.)
| | - Lily Paemka
- Department Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG54 Legon, Ghana; (L.P.); (P.K.A.)
- West Africa Center for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana;
| | - Bernard O. Asimeng
- Department of Biomedical Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana;
| | - Srinivasan Balapangu
- West Africa Center for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana;
- Department of Biomedical Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana;
| | - Patrick K. Arthur
- Department Biochemistry, Cell and Molecular Biology, University of Ghana, P.O. Box LG54 Legon, Ghana; (L.P.); (P.K.A.)
- West Africa Center for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana;
| | - Elvis K. Tiburu
- West Africa Center for Cell Biology of Infectious Pathogens, University of Ghana, Legon, Ghana;
- Department of Biomedical Engineering, University of Ghana, P.O. Box LG77 Legon, Ghana;
- Correspondence: ; Tel.: +233-559-585-194
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