Adsorption Characteristics of Cd²⁺ Ions in Aqueous Solution on Modified Straw Biochar

Round 1

Reviewer 1 Report

In this study, effect of metal nps modified biochar have studied on removal of Cd ion from wastewater. Authors have done a lot of study and well presented the data but there are many grammatical, typo and other technical mistakes. Consider the following points to improve your manuscripts for possible publication in Sustainability.  

1.      Rewrite the title with clear understanding which reflect this study.

2.      Abstract is not written well and there are typo mistakes as well, check line 6. The language is very poor in abstract, revise the abstract with main results and findings obtained in this study.

3.      Introduction section does not reflect the strong background and there only 8 references in this section. Improve it with more citation. Help can be taken from the following new references on adsorption studies.

https://doi.org/10.1016/j.chemosphere.2023.137824, https://doi.org/10.1007/s44246-022-00007-3, Ahmed Abutaleb et al 2021 EPL 135 30005, https://doi.org/10.1016/j.envres.2021.112243, https://doi.org/10.1016/j.jwpe.2022.103405

 

4.      In the first two line of last paragraph in the introduction section, the meaning of sentence is not clear, what does it mean by iron modification, manganese modification…does it mean, biochar was modified by iron metal, manganese etc. then writes it properly.

5.      Rewrite the last paragraph of introduction with mentioning novelty of the work and actual work done in this study with proper meaning and full understanding.

6.      Section 2.1 Experimental materials- complete the sentences in this section and rewrite in proper way. Experimental material or materials- check grammar though whole manuscript.

7.      Section 2.2.1 rewrite this para, it looks like written in manual of the experiment. Similarly, for section 2.2.2, 2.2.3 and 2.2.4. Please check grammar and typo mistakes.

8.      In XRD section the peaks indicating positions at two theta angle 35.1 degree in FMBC1 and FMBC2 belongs to alpha Fe2O3. Use the citation. https://doi.org/10.1016/j.matlet.2019.126748

9.      Similarly, for manganese use the proper citation. https://doi.org/10.1021/acs.energyfuels.2c03370

10.  Fig. 4 usually we wrote “Concentration” of adsorbent on x-axis,

11.  Write Cd²⁺ ion everywhere in the manuscript. Take care of the subscript/superscript throughout the manuscript.

12.  Line 240-241, 242-but the adsorption rate of the biochar after the iron-manganese composite modification is higher than that of the original biochar, from the overall curve, please explain the reason of high adsorption with proper and recent references.

13.  Line 260-265-The adsorption 260 capacity of MBC2, FBC2, and FBC1 three modified biochars in this process is lower than  that of the original biochar, this shows that the modification of biochar increases its porosity, active sites and functional groups, but at the same time it also causes the internal  pore size of the biochar to become smaller, which prevents Cd2+ from entering the inside  of the biochar, how it can assume that those sample have high adsorption capacity has high porous structure, is it possible to provide BET surface area of the samples.

14.  It would be better if the findings from this study can be written in bullets form in the conclusion section. Write down the main findings from the results.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In this study, three methods of iron, manganese and iron-manganese compound modification were used to modify the physical and chemical properties of rice straw and corn straw biochar. FITR, SEM, XRD and other methods were used to characterize and analyze the surface structure of the biochar before and after modification, the surface functional groups of the biochar, and the internal atomic crystal structure of the biochar, finally, using the modified biochar as the adsorbent, the adsorption kinetics and isothermal adsorption experiments of Cd2+ in wastewater were carried out, and the adsorption effect and adsorption mechanism of kinds of biochar on Cd2+ in wastewater were compared and analyzed.

The results of the paper are interesting. I recommend the paper after minor revision. My comments are:

1) The abstract of the paper is too long and contains too many complex sentences. Please rewrite the abstract in a concise way and use simple English.

2 )The literature review is enough and are discussed in details. Please provide the structure of the paper at the end of the introduction part.

3)  There are some mathematical models of water waste which need to be discussed in the introduction part. I suggest :

a) On Numerical Analysis of Bio-Ethanol Production Model with the Effect of Recycling and Death Rates under Fractal Fractional Operators with Three Different Kernels

b) Mathematical analysis of biodegradation model under nonlocal operator in Caputo sense

4)  Figure 3 is not visible. Please correct the margin of the figure.

5) Please check the whole paper for typo and grammatical mistakes.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Write Cd²⁺ ions everywhere in the manuscript. This comment is not done. please check your manuscript carefully, it is written Cd²⁺ only, it must include ions.

Author Response

I have written Cd²⁺ ions everywhere in the manuscript. Thanks a lot for your suggestions.