Zinc Oxide/Moringa Oleifera Gum-Grafted L-Methionine-Functionalized Polyaniline Bionanocomposites for Water Purification
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
This paper aims to develop a biocomposite to eliminate cations (II) from water. The work is interesting and could be recommended after some minor revisions.
1. Some peaks attributed on the IR curves (Fig 2) are not clearly visible. Which mode is used KBr or ATR? The quality of all the figures in the manuscript should be improved for a good readability.
2. The kinetic and isotherm studies are not addressed in depth, for instance, the Langmuir model stating that materials have a uniform surface with equal adsorption sites could not reasonably explain the phenomenon. The recent achievements in this domain explain how this model cannot lead to any definitive conclusion.
3. Why did you choose linear kinetic models rather than nonlinear ones? I recommend authors to fit the experimental data with non-linear model to avoid common errors made during linearization.
4. The effect of pH should also be discussed in regard to the zero point of charge (pHpzc) of the materials.
5. Adsorption remains a surface phenomenon and the study of morphology alone is not enough, the authors should provide the measurement of the specific surface area as well as the pore volume of the different material used, this is crucial in such a study.
Most of the articles reviewer receive on absorption unfortunately present the same shortcomings, notably the use of obsolete models to explain kinetics and isotherms. Very often reviewer find the classic pseudo-first and second order models or Langmuir and Freundlich models which most often cannot explain such phenomena given the heterogeneity of the surface of the composites used. Much more, some authors continue to use linear models while many authors have demonstrated that non-linear models are better suited in view of the errors during linearization. Finally, pH being a very determining factor in such a study, focusing only on the effect of pH on adsorbates without taking into account this effect on the surface of the adsorbent is an error.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1. Add reference for preparation of Gum and ZnO NPs in the experimental section
2. Describe the characterization techniques used in greater detail, such as the specific parameters measured for IR, or SEM, or the wavelength of the elements that are used in ICP
3. Explain the adsorption experimental procedures, including sorbent dosage, contact time, pH control, etc.
4. Expand on the correlations between adsorbent properties (e.g., surface area, pore volume) and adsorption performance.
5. Explanation about the theory of equilibrium of kinetic studies should go in the experimental section, not in the results
6. Discuss potential synergistic or antagonistic effects between different adsorbent properties on HM removal.
7. Delve deeper into the proposed adsorption mechanisms, providing more evidence and supporting data.
8. Compare the findings to relevant literature more extensively to contextualize the results.
9. Highlight the significance and novelty of using your adsorbent as a sustainable adsorbent for HM wastewater treatment.
10. Discuss potential scale-up considerations and real-world applicability of the biochar adsorbents.
11. I would like to see a table of comparison of analytical parameters of the proposed method with other reported methods.
12. Study limitations should be included in methodology and discussion section
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for Authorsit is good to publish
