The main goal of the work was to study the Moringa oleifera leaves and seeds as sorbents against Pb(II), Cd(II), Co(II), and Ni(II) from aqueous solutions, to explore the effect of various parameters (such as contact time, biosorbent dosage, and initial concentration of metals) and to determine the adsorption mechanisms [1].
In the original publication, there were some errors in Figure 2 and on the discussion about it. Since the XRD analysis of these biomass-derived materials is not crucial due to their amorphous nature, and considering also that the XRD analysis does not affect the experimental conclusions regarding the remediation efficiency, the authors would like to remove mentions of XRD analysis, the Figure 2 of XRD spectra, and the discussion related to XRD analysis (Section 3.2).
The XRD analysis is not necessary as it does not affect the main scope and experimental conclusions regarding the remediation performance of the studied biomass-derived materials. The scientific conclusions remain unaffected.
The phrase “X-ray Diffraction (XRD)” has been removed from line 6 of the Abstract.
The last sentence at the Section 2.3, first paragraph: “The L-MO and S-MO samples were also characterized by employing an X-ray diffractometer. The samples’ XRD patterns were recorded at 30 kV and 25 mA in the range of 2θ from 5° to 70° at a 2°/min scan rate.” has also been removed.
The XRD patterns have been removed in Section 3.2:
“Figure 2a,b shows the X-ray diffractograms of L-MO and S-MO powders before and after the sorption of heavy metals. The XRD pattern of L-MO shows weak and poorly resolved peaks indicating the predominance of the amorphous nature of the biosorbent. This pattern has been observed for other biosorbents where the heavy metals could be more easily sorbed in the surface [34,35]. After L-MO interactions with Co(II) and Cd(II), the XRD patterns showed an increase in the peaks’ intensity, suggesting the deposition of heavy metals and/or that those specific interactions took place. In Figure 2b, the XRD patterns of Pb(II), Cd(II), Co(II), and Ni(II) loaded S-MO exhibited a similar broad peak at around 19.6° and 22.4°. The presence of this peak in Moringa seeds was also reported in previous studies, which was associated with the presence of cellulose, proteins, or lipids [36]”.
Removed Figure 2 is shown below:
Figure 2.
XRD patterns of (a) L-MO, L-MO-Pb, L-MO-Cd, L-MO-Co, and L-MO-Ni; and (b) S-MO, S-MO-Pb, S-MO-Cd, S-MO-Co, and S-MO-Ni [1].
Figure 2.
XRD patterns of (a) L-MO, L-MO-Pb, L-MO-Cd, L-MO-Co, and L-MO-Ni; and (b) S-MO, S-MO-Pb, S-MO-Cd, S-MO-Co, and S-MO-Ni [1].
The last sentence in the first paragraph of Section 3.3, FTIR Spectra “These results were also corroborated the XRD data after the adsorption, where no new crystalline phase was observed.” has been removed.
The phrase “XRD and” in the first sentence of the second paragraph of Section 3.3 FTIR Spectra has been removed.
In Acknowledgments, the phrase “X-ray diffraction and” has been removed.
References [34–36] have been removed from the Reference Section, and all other references in further text rearranged accordingly.
This correction was approved by the Editorial Board Member and Editor-in-Chief of Coatings. The original publication has also been updated.
Ultimately, the authors regret about these issues.
Reference
- Abatal, M.; Olguin, M.T.; Anastopoulos, I.; Giannakoudakis, D.A.; Lima, E.C.; Vargas, J.; Aguilar, C. Comparison of Heavy Metals Removal from Aqueous Solution by Moringa oleifera Leaves and Seeds. Coatings 2021, 11, 508. [Google Scholar] [CrossRef]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).