| Autor: |
Patience M. Shilowa, Bamidele J. Okoli, Olugbemi T. Olaniyan, Johannes S. Modise, Fanyana Mtunzi |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Environmental Challenges, Vol 3, Iss , Pp 100058- (2021) |
| Druh dokumentu: |
article |
| ISSN: |
2667-0100 |
| DOI: |
10.1016/j.envc.2021.100058 |
| Popis: |
Quantity of water is a major concern, but the quality is of more urgent concern due to heavy metal pollution. In this study, the focus was to develop adsorbents (tannin resin (TR) and iron-doped tannin resin (Fe-TR)) from invasive Acacia mearnsii for Pb2+ and Ni2+ in solution. The developed TR and Fe-TR were prepared directly by crosslinking and iron-grafting; respectively with thermal stable at ≤ 350 °C. Surface functionality analysis revealed the presence of chelating groups at ≈ 1688 and 3661 cm−1. The crystallite sizes of the adsorbents were smaller compared to tannin; however, the % carbon and nitrogen were significantly higher. Also, the Brunauer–Emmet–Teller study revealed that iron-grafting of tannin after crosslinking increases the surface area, pore volume and pore size. Furthermore, the surface morphology of adsorbents indicated a well-defined structure with the formation of a whitish deposit and rough lump-like after ion uptake. Both adsorbents showed a type II isotherm with adsorption capacities of 40.650 mg/g and 13.763 mg/g for Pb2+and 120.63 mg/g and 110.74 for Ni2+ ion by TR and Fe-TR; respectively. The absorbate-adsorbent interactions were observed to be endothermic with negative and positive Gibb's free energy values for the adsorption of Pb2+ and Ni2+; respectively. The adsorption kinetics of Ni2+ is governed by several models; however, Pb2+ interaction is regulated by Pseudo-second-order model. Furthermore, the data generated offered the possibility of both chemisorption and physisorption processes; highlighting the flexibility and multifunctionality of tannin traps for the erasure of ion impurities in wastewater. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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