The Role of Surface Functional Groups of Iron Oxide, Organic Matter, and Clay Mineral Complexes in Sediments on the Adsorption of Copper Ions

Round 1

Reviewer 1 Report

I believe that the journal choice is totally wrong - you should submit the manuscript to  a surface science journal .However clarify the at least the form of copper and so not use methods used which were referenced used with different metals . the presentation of the references is incorrect and links to the references are lacking. further what about the Z-potentiahttps://en.wikipedia.org/wiki/Zeta_potential

l 

 

Author Response

22- September-2022

Dear reviewer:

We would like to thank you for the careful and constructive reviews. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to your suggestions. We have uploaded a clean version with the latest changes.

The following is a response to the revision：

 

I believe that the journal choice is totally wrong - you should submit the manuscript to a surface science journal. However, clarify the at least the form of copper and so not use methods used which were referenced used with different metals. the presentation of the references is incorrect and links to the references are lacking. further what about the Z-potentiahttps://en.wikipedia.org/wiki/Zetapotential.

 

Response: Thanks for your comments. First of all, the subject of our research focuses on the prevention and control of heavy metals in the estuary of the lake. The study of the adsorption mechanism of the complex can better grasp the adsorption law of heavy metals, so as to achieve environmental sustainability. Secondly, we have mentioned copper ions many times in the article, not without a clear copper form. And there are many studies on copper adsorption, and there is no problem of incorrect treatment of copper ions. Thirdly, we have adjusted to the journal's reference format. Finally, we have added relevant comments about zeta potential and copper ion adsorption in the article, which helped us a lot, thank you again.

 

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 2 Report

The present manuscript shows the potential in providing new inputs to scientific readers but it needs clarification as mentioned below-

1. Line 126-127. Removal of Fe-oxides was given from sample B but no mention of the Al-oxides removal. Please revise. 

2.  Line 149-152. The statement is too long and complex. Please state the reaction setups clearly. 

3. Line 196. 'R_L is a dimensionless constant...' but in Table 2, it was written K_L. Please revise. 

4. Please mark or write groups on the major peaks of the FTIR and XRD graphs. It is recommended to provide peak markings for a better understanding. 

5. RDA was performed with which samples, were not mentioned. Please provide RDA data for all 8 different samples. 

6. Table 3 and Table 4 represent data from which study sites or samples ? 

7. Line 261-262. Fe-oxides and Al-oxides were mentioned to be better for Cu adsorption than SOM. But in the earlier paragraph (line 225-230) and later (line 330), it was mentioned that the OH group in SOM is better for Cu adsorption. Please rectify. 

8. Line 319-321. It was mentioned that the adsorption amount of Cu in group C did not increase with the increase of iron and aluminum oxides. But in the previous paragraph, it was mentioned that Fe and Al oxides are higher in Group C samples and hence the adsorption was higher. Please rectify. 

9. Too many repetitions of similar statements in the whole result-discussion section. Please minimize such repetitions.

10. Provide more references in the discussion section. This part is not well-referenced. 

Author Response

22- September-2022

Dear reviewer:

We would like to thank you for the careful and constructive reviews. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to your suggestions. We have uploaded a clean version with the latest changes.

The following is a response to the revision：

 

1. Line 126-127. Removal of Fe-oxides was given from sample B but no mention of the Al-oxides removal. Please revise. 

Response: Thanks for your comments. In nature, iron oxides and aluminum oxides often coexist. It can also be seen from Table 1 that the content of aluminum oxides in group B decreases while the iron oxides decrease.

2. Line 149-152. The statement is too long and complex. Please state the reaction setups clearly. 

Response: Thank you for your suggestion. We have simplified this section accordingly to make it clearer and more concise for the reader.

3. Line 196. 'R_Lis a dimensionless constant...' but in Table 2, it was written K_L. Please revise. 

Response: Thanks for pointing out our mistakes. We have modified this.

4. Please mark or write groups on the major peaks of the FTIR and XRD graphs. It is recommended to provide peak markings for a better understanding. 

Response: According to your opinion, we have added the peaks of the main changes to the FTIR and XRD graphs to make the changes more intuitive to the reader.

5. RDA was performed with which samples, were not mentioned. Please provide RDA data for all 8 different samples. 

Response: Thanks for your comments. In section 4, we have written “To further explore the relationship between SOM content, CEC, pH, iron oxide, and aluminum oxide and adsorption capacities of the three groups, redundancy analysis (RDA) was conducted, where the three groups were considered as species and SOM content, CEC, pH, iron oxide, and aluminum oxide were considered as environmental factors.”, and the sample data are in Table 1 and Supplementary Data Figure S1.

Location	Group	CEC（coml/kg）	SOM（mg/g）	Free Iron Oxide（mg/g）	Aluminum oxide（mg/g）	pH
CH	A	1.09	32.57	62.13	11.72	8.18
CH	B	9.73	44.69	7.83	1.22	9.15
CH	C	31.27	34.39	35.51	6.06	8.49
DD	A	0.80	20.72	41.60	4.27	7.25
DD	B	9.63	35.89	3.37	0.81	9.50
DD	C	32.25	46.58	26.55	4.92	7.97
GS	A	1.48	33.66	45.71	3.42	8.14
GS	B	14.45	44.54	4.50	0.91	8.81
GS	C	45.36	49.12	30.73	4.68	8.25
GP	A	2.15	31.08	52.60	4.94	8.06
GP	B	26.01	66.98	5.85	1.18	8.69
GP	C	56.87	48.81	35.23	5.33	8.02
LY	A	1.80	21.44	76.04	8.16	7.95
LY	B	20.92	46.90	5.79	0.81	9.18
LY	C	52.33	46.65	49.59	5.85	8.02
LB	A	0.81	22.66	37.03	5.89	7.39
LB	B	6.90	29.24	3.52	0.84	8.51
LB	C	20.77	37.47	28.27	4.78	7.91
XH	A	0.44	21.52	26.52	4.71	8.39
XH	B	2.42	19.50	1.10	0.30	9.46
XH	C	18.71	31.96	8.98	1.07	8.35
YN	A	2.08	18.38	131.02	15.06	7.51
YN	B	19.15	24.50	17.30	2.11	9.18
YN	C	57.92	24.83	85.05	9.59	8.06

 

6. Table 3 and Table 4 represent data from which study sites or samples? 

Response: Thanks for your comments. Table 3 represents the relevant parameters of the redundancy analysis, and Table 4 represents correlation between sediment components and adsorption capacity.

7. Line 261-262. Fe-oxides and Al-oxides were mentioned to be better for Cu adsorption than SOM. But in the earlier paragraph (line 225-230) and later (line 330), it was mentioned that the OH group in SOM is better for Cu adsorption. Please rectify. 

Response: Thanks for your comments on the writing. We have reanalyzed the results and concluded that both organics and iron oxides contributed to Cu adsorption, but iron oxides contributed more. As we mentioned "After the adsorption of copper ions, the zeta potential was gradually neutralized, and the electrostatic repulsion between iron oxides was reduced, making them aggregate and combine together, which reduced the adsorption sites of iron oxides, thereby reducing the amount of adsorption. However, in group C, the amount of Cu adsorption increased significantly after bridging by organic matter, while in group B, the lower content of iron oxides affected the adsorption of Cu by organic matter-clay mineral complex." in Section 4, it is important to study the specific combination of iron oxide with organic and inorganic ligands to understand its effect on heavy metal adsorption and stabilization efficiency.

8. Line 319-321. It was mentioned that the adsorption amount of Cu in group C did not increase with the increase of iron and aluminum oxides. But in the previous paragraph, it was mentioned that Fe and Al oxides are higher in Group C samples and hence the adsorption was higher. Please rectify. 

Response: Thanks for pointing out the question. We have removed the expression "the adsorption amount of Cu in group C did not increase with the increase of iron and aluminum oxides". After analyzing of the experimental results, we found that the content of iron oxides had a greater effect on the adsorption of copper ions, and the organic matter more only played a bridging role, which could be seen in the revised manuscript.

9. Too many repetitions of similar statements in the whole result-discussion section. Please minimize such repetitions.

Response: Thanks for your opinion on writing. In the Results and Discussion sections, we have removed many repeated statements and synthesized statements with similar meaning to make the manuscript more concise to read.

10. Provide more references in the discussion section. This part is not well-referenced. 

Response: Thanks for your comments. In the Discussion section, we have inserted further references, making this part well-referenced.

 

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 3 Report

sustainability-1867006

The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions.

 

Major Revision is required.

 

1.   R² is the determination coefficient instead of the correlation coefficient.

2.   The unit of K_F is mg g^^-1 (mg L^^-1)^^-1/nF. ^means exponent.

3.   Table 2- The parameters' standard deviations or standard errors are much higher than expected. As an example, 1.86 +/- 1.05; 0.43 +/- 0.72.

4.   RL (Langmuir) equation makes no sense in the manuscript since R_L will always be lower than 1. The only possibility of R_L being > 1 is if K_L or C_o is negative. Considering that there is no negative concentration and no negative equilibrium constant, R_L will always be < 1 if the Langmuir isotherm model is fitted. Based on that, I request that you remove this from the manuscript. I perfectly know that there are a lot of mistakes similar to yours spread entirely in the literature.

5.   Si-O-Si is called siloxane and not silicide.

6.   Section 3.2.1- It is hard to understand that C-H groups could complex metallic ions. Also, siloxane is a very stable chemical bond and is not expected of complex metallic ions. Therefore, the interaction that could take place is superficial adsorption.

 

7.   Figures 2 and 3 are not histograms.

Author Response

22- September-2022

Dear reviewer:

We would like to thank you for the careful and constructive reviews. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to your suggestions. We have uploaded a clean version with the latest changes.

The following is a response to the revision：

 

1. R² is the determination coefficient instead of the correlation coefficient.

Response: Thanks for pointing out our mistakes. We have corrected this to keep the parameter names correct.

2. The unit of K_Fis mg g^^-1 (mg L^^-1)^^-1/nF. ^means exponent.

Response: Thanks for your comments. We have added the units of K_f to Table 2 in the manuscript.

3. Table 2- The parameters' standard deviations or standard errors are much higher than expected. As an example, 1.86 +/- 1.05; 0.43 +/- 0.72.

Response: Thanks for your comments. Although there were two individual data in Table 2 that were not in line with expectations, most of the other data could represent the research results and the conclusions we had reached, so we believe that this was caused by the volatility of the experiment, and the overall results were acceptable.

4. RL (Langmuir) equationmakes no sense in the manuscript since R_L will always be lower than 1. The only possibility of R_L being > 1 is if K_L or C_o is negative. Considering that there is no negative concentration and no negative equilibrium constant, R_L will always be < 1 if the Langmuir isotherm model is fitted. Based on that, I request that you remove this from the manuscript. I perfectly know that there are a lot of mistakes similar to yours spread entirely in the literature.

Response: Thanks for your comments. Although the value of R_L always was 0<R_L<1, the value of RL could represent the favorable degree of adsorption, which was helpful for us to judge the trend of adsorption.

5. Si-O-Si is called siloxane and not silicide.

Response: Thanks for pointing out our mistakes. We have corrected this to keep the noun names correct.

6. Section 3.2.1- It is hard to understand that C-H groups could complex metallic ions. Also, siloxane is a very stable chemical bond and is not expected of complex metallic ions. Therefore, the interaction that could take place is superficial adsorption.

Response: Thanks for your comments. According to our experimental results, the functional groups mentioned by you have indeed changed. We do not deny that there is a certain surface adsorption, but we cannot ignore the coordination and complexation that occur between them.

7. Figures 2 and 3 are not histograms.

Response: Thanks for pointing out our mistakes. We've fixed the mistake and fixed the names of Figures 2 and 3.

 

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 4 Report

In this study, the characteristics and rule of Cu adsorption to organic–inorganic, inorganic minerals, and iron-oxide–clay complexes in the estuary sediments of the Dianchi Lake were explored . The Langmuir and Freundlich isotherm models were used to Cu adsorption experiments on three complexes to study their adsorption kinetics. The results showed that Freundlich isothermal model was better than Langmuir model in describing adsorption behavior of the adsorbents. It was also found that organic-inorganic complex had the strongest Cu adsorption capacity. It is significant for the theoretical understanding of adsorption in multi-component-complex system. Accordingly, the corresponding technology for metal ions removal in estuary sediments will be developed. I suggest that it could be accepted after a  revision of English grammar.

Author Response

22- September-2022

Dear reviewer:

We would like to thank you for the careful and constructive reviews. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to your suggestions. We have uploaded a clean version with the latest changes.

The following is a response to the revision：

In this study, the characteristics and rule of Cu adsorption to organic–inorganic, inorganic minerals, and iron-oxide–clay complexes in the estuary sediments of the Dianchi Lake were explored. The Langmuir and Freundlich isotherm models were used to Cu adsorption experiments on three complexes to study their adsorption kinetics. The results showed that Freundlich isothermal model was better than Langmuir model in describing adsorption behavior of the adsorbents. It was also found that organic-inorganic complex had the strongest Cu adsorption capacity. It is significant for the theoretical understanding of adsorption in multi-component-complex system. Accordingly, the corresponding technology for metal ions removal in estuary sediments will be developed. I suggest that it could be accepted after a revision of English grammar.

Response: Thank you for your recognition of our manuscript. We have made corrections to English grammar errors in the manuscript.

 

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 5 Report

This study focuses on the Cu adsorption mechanisms using the organic-inorganic, inorganic minerals, and iron-oxide-clay complexes in the estuary sediments of the Dianchi Lake as adsorbents. The relationship between adsorption capacity and the functional groups of those complexes is further analyzed and conducted. In general, the experimental data is sufficient and the analysis is credible. I am glad to recommend this paper to publish in Sustainability if the authors could resolve the following issues:

1) Why is the heavy metal Cu selected in current study?  Could the  mechanism obtained in this study be extrapolated to other heavy metals?

2) The authors should give the characterization information of three materials (group A and group B) to comfirm if relizing the removal of organic matter and free iron oxides, respectively.

3) The authors should give the Fourier transform infrared spectra of the materials before the adsorption in Fig. 2 for comparison.

Author Response

22- September-2022

Dear reviewer:

We would like to thank you for the careful and constructive reviews. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to your suggestions. We have uploaded a clean version with the latest changes.

The following is a response to the revision：

 

Comments and Suggestions for Authors

This study focuses on the Cu adsorption mechanisms using the organic-inorganic, inorganic minerals, and iron-oxide-clay complexes in the estuary sediments of the Dianchi Lake as adsorbents. The relationship between adsorption capacity and the functional groups of those complexes is further analyzed and conducted. In general, the experimental data is sufficient and the analysis is credible. I am glad to recommend this paper to publish in Sustainability if the authors could resolve the following issues:

1) Why is the heavy metal Cu selected in current study?  Could the mechanism obtained in this study be extrapolated to other heavy metals?

Response: Thanks for your comments. The reason why we chose copper is that in the Dianchi Lake area, the pollution load of copper was higher than that of other heavy metal elements, which could represent the heavy metal pollution in this area.

2) The authors should give the characterization information of three materials (group A and group B) to comfirm if relizing the removal of organic matter and free iron oxides, respectively.

Response: Thanks for your comments. We have given the Fourier transform infrared spectrum and XRD pattern as characterization information, and have completed Table 1, in which the differences in the content of organic matter and iron oxides of the three groups of complexes can be seen, and it can be considered that organic matter and iron oxides are removed.

3) The authors should give the Fourier transform infrared spectra of the materials before the adsorption in Fig. 2 for comparison.

Response: According to your opinion, we have given the Fourier transform infrared spectra of the materials before the adsorption in Fig. 2. Attaching the picture below.

 

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

 

Author Response File: Author Response.docx

Reviewer 6 Report

I accept the material in revised form.

 

Author Response

Dear reviewer:

Thank you for your recognition of our manuscript.  Thank you very much again.

Best regards,

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 7 Report

Line 58:  Erie, kaolin and montmorillonite - why Erie, as mineral data?

Line 77: explain which factor...

Overall: The graphics are of poor quality, the size of the letters and numbers is almost invisible - please improve the quality. 

Author Response

Dear reviewer:

We would like to thank you for the careful guidance. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to suggestions. We have uploaded a clean version with the latest changes.

 

The following is a response to the revision：

Line 58: Erie, kaolin and montmorillonite - why Erie. as mineral data?

Response: Thanks for your comments. We have changed the word "Erie" to "illite" to better convey our following content.

 

Line 77: explain which factor.

Response: Thanks for your comments. The "main factor" here refers to the fact that copper ions account for most of the total content of natural process pollutants among the common heavy metal pollutants in the Dianchi basin, and therefore have a high pollution load. We have now modified this sentence to read "According to the study, the copper pollution load in the Dianchi watershed is relatively large among natural process pollutants, so we used sediments from the Dianchi estuary as the study object" for better understanding.

 

Overall: The graphics are of poor quality, the size of the letters and numbers is almost invisible. please improve the quality.

Response: Thanks for your comments. We have made the appropriate changes to Figure 2, Figure 3 and Figure 5.

 

All modified parts are marked with red font.

 

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

 

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

i STILL DO NOT RECOGNIZE THE SIGNIFICANCE OF THE WORK  FOR IMPROVING SUSTAINABILITY . IT IS THE ADSORPTION BEHAVIOR OF THE SEDIMENT AND AND AS SUCH CONTRIBUTES NOTHING TO THE SUSTAINABILITY . I RECOMMEND AGAIN AN OTHER JOURNAL 

Author Response

Dear reviewer:

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 2 Report

Authors tried to revise the manuscript and addressed all the queries and suggestions. At present, the manuscript is more well-represented than before. The manuscript needs a little more revision and careful cross-checking on English and grammatical errors before further processing.

Author Response

Dear reviewer:

We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Reviewer 3 Report

I did not receive the letter with the response to the reviewers. It is very hard to read a manuscript with the track version of Microsoft Word. Please show only the changes made in the present text and not the past version. The RL requested to remove from the Tables remain in the text. It was not possible to verify if the authors did made the changes requested in the previsous version without the response letter

Author Response

Dear reviewer:

I'm very sorry that I forgot to upload my revisons due to my negligence. We are appreciated for your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

no further commrent

Author Response

15-March-2023

Dear reviewer:

We would like to thank you for the careful guidance. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to suggestions. We have uploaded a clean version with the latest changes.

Thank you for your continued criticism and guidance, which has resulted in a richer manuscript. The knowledge about zeta potential, copper adsorption, and the requirements for the figure has improved us.

 

We are appreciated your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to the submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

 

Best wishes to you.

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

 

Author Response File: Author Response.docx

Reviewer 3 Report

Two questions were not responded to by the Authors. RL should be removed from the text. 

The C-H and Si-O-Si could not be complexed with any specie. It seems that the authors have difficulties with simple concepts of chemistry. How could I be confident in research, where the authors have a low domain in chemistry?

Author Response

15-March-2023

Dear reviewer:

We would like to thank you for the careful guidance. We revised the manuscript (sustainability-1867006) entitled “The role of surface functional groups of iron oxide, organic matter, and clay mineral complexes in sediments on the adsorption of copper ions” according to suggestions. We have uploaded a clean version with the latest changes.

We have removed the relevant parts of R_L as you requested. the issue of C-H and Si-O-Si complexes has also been removed to some extent, and the remaining parts have been revised to a more appropriate description.

The revision of the original text is as follows:

1.Line 199

Table 2. Freundlich isothermal model and Langmuir isothermal model parameters.

Site	Group number	Freundlich model			Langmuir model
		Kf(mg/g) [23]	1/n	R2	Qmax (mg/kg)	R2
CH	A	0.35 ± 0.06	1.28 ± 0.51	0.9956	4.85 ± 4.43	0.92616
	B	4.01 ± 0.64	0.64 ± 0.08	0.99698	26.38 ± 4.00	0.99831
	C	1.79 ± 0.52	0.77 ± 0.12	0.99375	55.11 ± 53.37	0.99084
DD	A	0.42 ± 0.10	0.87 ± 0.07	0.9995	43.69 ± 15.02	0.99967
	B	0.75 ± 0.36	0.23 ± 0.16	0.99928	2.06 ± 0.53	0.99961
	C	1.86 ± 1.05	0.43 ± 0.18	0.99332	7.53 ± 1.76	0.99088
GS	A	1.71 ± 0.22	0.75 ± 0.05	0.99851	33.33 ± 4.39	0.99892
	B	3.57 ± 0.77	0.82 ± 0.14	0.99635	52.51 ± 0.36	0.99721
	C	3.52 ± 0.20	0.27 ± 0.02	0.99993	10.66 ± 0.94	0.99904
GP	A	0.63 ± 0.21	1.03 ± 0.12	0.99453	219.97 ± 743.21	0.99457
	B	2.84 ± 0.17	0.94 ± 0.04	0.99975	153.14 ± 1.19	0.99979
	C	4.82 ± 0.42	0.54 ± 0.05	0.99894	21.82 ± 0.84	0.99978
LY	A	0.51 ± 0.28	0.68 ± 0.14	0.9993	46.25 ± 90.69	0.99898
	B	2.56 ± 0.64	0.65 ± 0.11	0.99751	19.28 ± 1.38	0.99882
	C	5.29 ± 0.43	0.13 ± 0.02	0.99987	9.22 ± 0.28	0.9999
LB	A	0.53 ± 0.29	0.74 ± 0.15	0.99815	23.51 ± 12.12	0.99827
	B	1.42 ± 0.27	0.85 ± 0.08	0.99683	46.30 ± 14.51	0.99808
	C	2.83 ± 0.40	0.46 ± 0.05	0.99869	17.38 ± 2.83	0.99507
XH	A	0.39 ± 0.08	0.88 ± 0.06	0.9997	45.60 ± 14.48	0.9998
	B	1.01 ± 0.50	0.52 ± 0.13	0.99799	10.39 ± 1.72	0.999
	C	3.07 ± 4.50	0.37 ± 0.50	0.94052	10.05 ± 4.21	0.94166
YN	A	2.52 ± 0.39	0.72 ± 0.06	0.99237	28.60 ± 6.55	0.99581
	B	5.02 ± 2.30	0.34 ± 0.15	0.9735	19.40 ± 3.35	0.9844
	C	1.24 ± 0.22	0.65 ± 0.06	0.99916	24.64 ± 8.09	0.99748

2．Lines 209-211:

The spectral features of group B indicate that functional groups such as -OH and -COOH react through coordination or complexation, while -CH, silicide, and siloxane mainly undergo surface adsorption.

 

3. Lines 357-359:

Silicides (e.g., Si–O–Mg stretching vibrations), siloxane (e.g., Si-O-Si stretching vibrations), and –CH participated in the specific adsorption of Cu through surface adsorption.

We are appreciated your help with this manuscript. We tried our best to revise this manuscript according to your suggestions to the submitter. We are longing for your help with new progress on our manuscript. Thank you very much again.

 

Sincerely,

Xiao Long Sun.

College of Wetlands, Southwest Forestry University,

Kunming 650224, China.

Email address: [email protected]

 

Author Response File: Author Response.docx