Photocatalytic Performance of Functionalized Biopolymer for Neodymium (III) Sorption and the Recovery from Leachate Solution

Round 1

Reviewer 1 Report

Dear Editor

The manuscript entitled “Photocatalytic Performance of Functionalized Biopolymer for Neodymium (III) Sorption and the Recovery from Leachate Solution” needs critical improvement in grammar and incomplete sentences. In the current form, I recommend rejection.

The text of this paper needs a thorough review, as there are multiple spelling and grammatical errors

Concerning the analyses, it seems that the authors try to provide the results of many techniques, without a deep discussion of the obtained results:

1. Please explain, what is the relevance of BET analyses in this work? The surface area is very low  23.85 m2/g

2. What is the relevance of pHpzc results (6.28 and 6.58), if sorption process is carried out at pH 4 ?

3.What is the relevance of EDX analyses? Please move Figure 7 to supplementary materials section

The introduction section does not highlight the scientific aspects of using chitosan in this work, please supply more and cite more reference:

Zhang et al. (https://doi.org/10.1016/j.jes.2021.01.009) evaluated the introduction of ammonium quaternary groups and La(OH)3 for increasing the selectivity towards phosphate ions by immobilizing nano-sized La(OH)3

4. The authors reported that a contact time of 20 min represents "fast kinetic sorption". I do not agree with this; 20 min. of contact time is very low to be up-scaled to an industrial system, which requires very short reaction times (some seconds).

5. Please improve Figure 1 it is not clear.

6. The sorption capacities provided in Tables 1, 2 and 3 are in mmol/g or in mg/g??

7. Figures 9 and 11 are not clear. Please provide a table instead of figures in 3D

8. Line 376 (page13): concertation or concentration ?

9. –Conclusion: the theoretical mechanisms and limitations of the study should be clearly reported

10.  It has been detected inappropriate self-citations by authors (the authors have cited at least 15 self-articles, which is too much).

Author Response

RESPONSE to REVIEWER#1

 Red: Specific response to Reviewer comment.

Blue: New statement added to the revised manuscript

We would like to thank the reviewer for the careful reading of the manuscript and meaningful suggestions. We hope the revised version will comply with his/her expectations.

 Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

Quality of English Language

( ) English very difficult to understand/incomprehensible
(x) Extensive editing of English language and style required
( ) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I am not qualified to assess the quality of English in this paper

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	( )	(x)	( )
Are all the cited references relevant to the research?	( )	( )	(x)	( )
Is the research design appropriate?	( )	( )	(x)	( )
Are the methods adequately described?	( )	( )	(x)	( )
Are the results clearly presented?	( )	(x)	( )	( )
Are the conclusions supported by the results?	( )	( )	(x)	( )

Comments and Suggestions for Authors

Dear Editor

The manuscript entitled “Photocatalytic Performance of Functionalized Biopolymer for Neodymium (III) Sorption and the Recovery from Leachate Solution” needs critical improvement in grammar and incomplete sentences. In the current form, I recommend rejection.

Thank，we are sorry for hearing his/her recommendation, we revised the manuscript according the suggestions requested from the reviewers and hope the revised version met his/her expectation

The text of this paper needs a thorough review, as there are multiple spelling and grammatical errors

We try best to fix the English language and the grammatical errors in the revised version

Concerning the analyses, it seems that the authors try to provide the results of many techniques, without a deep discussion of the obtained results:

Thanks for attention, we thought that we provide a suitable (sufficient) discussion for each kind of analysis. Sometimes deep discussion (than necessary) makes confusion and unsatisfied case to the readers. Most of the readers follow the results of loading and the outcome of the synthesis. On the other hands, the manuscript in resent state including more than 9600 word counts beside the supplementary information and this is suitable the scientific article. Anyway, we try to support this part and hope will be sufficient for the reviewer, we believe more will be loaded on the manuscript.

1. Please explain, what is the relevance of BET analyses in this work? The surface area is very low  23.85 m2/g

We thank the reviewer for this comment, actually this is normal especially the SEM and TEM analyses provide a kind of agglomerate of particles due to the effects of magnetite. This work is matched to our previous work that appeared with these agglomerations and effects on the surface area properties.  

2. What is the relevance of pHpzc results (6.28 and 6.58), if sorption process is carried out at pH 4 ?

As the reviewer follow the discussion in the manuscript, the sorbent turns to completely negative at pH higher than 6 (this is the main relevance from the pHpzc, to give us a complete figure on the surface charge of the sorbent). During the study of the pH and pH_pzc effect, the sorbent becomes partially protonated (at slightly acidic pH values), which affects on the type of binding through electrostatic attraction, chelation (via ionic exchange or through the available pairs of electrons on the chelating atoms). In our opinions the pH 4 value gives much possibilists for efficient and varieties for binding mechanism especially for metal ions which have different ionic species.

Depending on this comment we design an expected sorption mechanism

 

Scheme 2. Expected binding mechanisms for Nd(III) sorption on CH-POH sorbent

    

3.What is the relevance of EDX analyses? Please move Figure 7 to supplementary materials section

Thanks for the comment, as shown, it provides the successive adsorption of Nd(III) ions without deteriorate of the sorbent structure’s (the presence of P and Fe) are the main important component in the structure, also the presence of S give us evidence that the sulfate species participate in the binding mechanisim.

As the reviewer suggested, we move the figure to the SI

The introduction section does not highlight the scientific aspects of using chitosan in this work, please supply more and cite more reference:

Zhang et al. (https://doi.org/10.1016/j.jes.2021.01.009) evaluated the introduction of ammonium quaternary groups and La(OH)3 for increasing the selectivity towards phosphate ions by immobilizing nano-sized La(OH)3

Thanks, we add the suggested reference and try to support the introduction by other update references   

This sentence was added

It has a singular property through the known polysaccharides because of cationic behavior, with facilities for dissolving, modification and shaping by the protonated amines. Improving the sorption kinetics and solid liquid separation by reducing the size through coating on magnetite and other nanoparticles for producing nano/micro structured composites. The presence of amines and hydroxyls on their structure make possibilities for the chemical modifications [62], recovering of metal ions and complexes. Several grafting groups were achieved; i.e., carboxylic group derivatives [63,64], poly(amines) [65,66], aminophosphonic [67,68] and phosphonic [69] moieties. Improving the selectivity of chitosan derivatives towards phosphate ions by immobilizing nano-sized La(OH)3[70].

4. The authors reported that a contact time of 20 min represents "fast kinetic sorption". I do not agree with this; 20 min. of contact time is very low to be up-scaled to an industrial system, which requires very short reaction times (some seconds).

Actually, we don’t agree with the reviewer on this point, many sorbents described as high sorption kinetics for the metal loading with higher sorption time than 30 min.  

5. Please improve Figure 1 it is not clear.

Thanks for the reviewer, we try best to improve it.

 

Figure 1. FTIR spectra of MCH, CH-POH, CH-POH+Nd, and after 5 cycles of sorption desorption

6. The sorption capacities provided in Tables 1, 2 and 3 are in mmol/g or in mg/g??

The sorption was assigned in these tables by mmol, we mentioned this in the text, and add a column for notification of the units.   

 Table 1. Uptake kinetics of the Nd(III)sorption using CH-POH sorbent under UV and VL parameters.

Model	Parameter	Unit	CH-POH#UV	CH-POH#VL
	qeq,exp	mmol Ndg-1	0.871	0.779
PFORE	qeq,1	mmol Ndg-1	0.891	0.785
	k1 × 10	min-1	0.395	0.582
	R2	-	0.996	0.991
	AIC	-	-102	-95
PSORE	qeq,2	mmol Ndg-1	1.08	0.886
	k2 × 10	gmmol-1 min-1	1.95	2.36
	R2	-	0.893	0.902
	AIC	-	-52	-44
RIDE	De × 108	m2 min-1	2.16	1.86
	R2		0.928	0.953
	AIC		-87	-89

 

 Table 2. Sorption isotherms of Nd(III) using CH-POH sorbent under UV and VL.

Model	Parameter	Unit	CH-POH_UV	CH-POH_VL
	qm,exp	mmol Nd g-1	1.45	1.33
Langmuir	qm,L	mmol Nd g-1	1.49	1.36
	bL	L mmol-1	3.68	2.25
	R2	-	0.991	0.989
	AIC	-	-130	-124
Freundlich	kF	L1/nF mmol1-1/nF g-1	1.37	1.95
	nF	-	2.86	2.53
	R2	-	0.855	0.872
	AIC	-	-39	-43
Sips	qm,S	mmol Nd g-1	1.51	1.42
	bS	(L mmol-1)1/nS	1.66	1.59
	nS	-	0.962	0.901
	R2	-	0.995	0.990
	AIC	-	-153	-133

 

7. Figures 9 and 11 are not clear. Please provide a table instead of figures in 3D

We thank the reviewers for this suggestion and we replaced them by tables

 Table 4. Selectivity studies of CH-POH in polymetallic equimolar solution under VL(a) and (UV) conditions

pHeq	VL				UV
	Nd/Fe	Nd/Ca	Nd/Mg	Nd/Al	Nd/Fe	Nd/Ca	Nd/Mg	Nd/Al
1.1	0.154	1.173	0.428	0.574	0.201	0.630	0.8278	0.531
2.12	4.118	5.578	3.781	6.344	3.665	7.193	4.934	9.321
3.18	6.2098	15.971	9.602	14.599	4.867	17.647	12.475	18.958
3.76	15.3938	34.587	22.628	32.78	16.388	44.328	51.68	44.212
4.75	13.385	34.481	22.213	34.789	19.561	53.803	58.013	50.147

 

Table 7. Effect of the pH values on sorption efficiencies of polymetallic ions using CH-POH; after treatment with amino-sulfonic chitosan composite

Conditions	pHeq	Nd/Zr	NdPb	Nd/Mg	Nd/Fe	Nd/Al	Nd/Ca
VL	1.16	12.345	5.4483	5.138	9.138	3.375	6.810
	2.19	7.306	7.1364	3.623	7.883	4.513	8.864
	3.27	11.565	12.461	10.383	19.911	9.197	15.956
	4.11	13.691	23.836	20.360	2.056	8.957	21.552
	4.89	12.567	23.874	23.558	1.424	3.559	24.567
UV	1.11	7.807	6.93	3.697	7.04	3.988	6.912
	2.15	10.029	14.255	3.613	11.313	7.861	9.65
	3.21	12.853	11.369	7.61	20.588	12.378	10.273
	4.1	14.243	26.82	17.862	2.305	12.42	13.745
	4.79	14.427	30.282	27.54	1.98	3.918	18.531

 

8. Line 376 (page13): concertation or concentration ?

Thanks, it was corrected

9. –Conclusion: the theoretical mechanisms and limitations of the study should be clearly reported

Thanks, it was added

10.  It has been detected inappropriate self-citations by authors (the authors have cited at least 15 self-articles, which is too much).

Thanks for the alerting, actually most of the references are important and essential, we try best to decrease this number and hope the revised version is suitable now.

 

 

 

 

 

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

In this work, the composite was prepared, and the neodymium element was tested for evaluating (under UV and VL conditions) in a new functionalized sorbent for sorption properties before applied for REEs recovery in pregnant raffinate solution. The experimental process is reasonably designed. But I think it should be revised before publishing. 

1. The current summary is too long, please refine the language.

2. Please check line 92, “under UV emission UV and……”, Please check whether the expression of this sentence is wrong.

3. The detail experimental conditions should be provided in the figure 6, 8, 10, 11.  

4. Please check the space between the percent sign and the number, it is not necessary, such as line 182-186, O%, 4.12%, et al.,

5. The unit parameters should be provided in the table.

6. Line 273-274, the sentence in the brackets: the initial slope of sorption capacities as a function of the metal residual concentrations, should be removed maybe better. 

7. Line 324, Please check the completeness of this sentence. Maximum adsorption..?or adsorption equilibrium was achieved in slightly acidic pH..? please express more clearly.

8. 2.2.4, Binding Mechanism, The mechanism was not explained clearly. Please give a clearer explanation according to the material characterization results.

9. The format of references should be unified, please check the page number of the reference carefully.

Author Response

RESPONSE to REVIEWER#2

Red: Specific response to Reviewer comment.

Blue: New statement added to the revised manuscript

We would like to thank the reviewer for the careful reading of the manuscript and meaningful suggestions. We hope the revised version will comply with his/her expectations.

 

Open Review

 

Review Report Form

Open Review

( ) I would not like to sign my review report
(x) I would like to sign my review report

Quality of English Language

( ) English very difficult to understand/incomprehensible
( ) Extensive editing of English language and style required
(x) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I am not qualified to assess the quality of English in this paper

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	(x)	( )	( )
Are all the cited references relevant to the research?	( )	(x)	( )	( )
Is the research design appropriate?	( )	(x)	( )	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	(x)	( )	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

In this work, the composite was prepared, and the neodymium element was tested for evaluating (under UV and VL conditions) in a new functionalized sorbent for sorption properties before applied for REEs recovery in pregnant raffinate solution. The experimental process is reasonably designed. But I think it should be revised before publishing. 

We thank the reviewer for the recommendation and try best improving the manuscript according to his/her suggestion

1. The current summary is too long, please refine the language.

Thanks, we try best to improve the language and fixe the grammars

2. Please check line 92, “under UV emission UV and……”, Please check whether the expression of this sentence is wrong.

Thanks, it was corrected

3. The detail experimental conditions should be provided in the figure 6, 8, 10, 11.  

Thanks, it was revised and the experimental conditions were provided in the revised version

4. Please check the space between the percent sign and the number, it is not necessary, such as line 182-186, O%, 4.12%, et al.,

Thanks for attention, it was revised accordingly in the whole manuscript

5. The unit parameters should be provided in the table.

Thanks, it was provided

6. Line 273-274, the sentence in the brackets: the initial slope of sorption capacities as a function of the metal residual concentrations, should be removed maybe better. 

Thanks for alerting, it was removed

7. Line 324, Please check the completeness of this sentence. Maximum adsorption..?or adsorption equilibrium was achieved in slightly acidic pH..? please express more clearly.

Thanks, it was revised and improved

8. 2.2.4, Binding Mechanism, The mechanism was not explained clearly. Please give a clearer explanation according to the material characterization results.

Thanks, it was improved in details and we provide the scheme of expected sorption mechanisms

Scheme 2. Expected binding mechanisms for Nd(III) sorption on CH-POH sorbent

9. The format of references should be unified, please check the page number of the reference carefully.

Thanks for alerting, but this is was arranged by endnote tools according to the journal style.

 

 

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript has been conceived and written well.

 

 

Author Response

RESPONSE to REVIEWER#3

We would like to thank the reviewer for his/her time consumed in reading the manuscript and the global recommendation that give to our work.

 

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

Quality of English Language

( ) English very difficult to understand/incomprehensible
( ) Extensive editing of English language and style required
(x) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I am not qualified to assess the quality of English in this paper

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	(x)	( )	( )
Are all the cited references relevant to the research?	(x)	( )	( )	( )
Is the research design appropriate?	(x)	( )	( )	( )
Are the methods adequately described?	( )	(x)	( )	( )
Are the results clearly presented?	(x)	( )	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

The manuscript has been conceived and written well.

We appreciate the global recommendation from the reviewer.

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Abstract: Please rephrase the first sentence as it is very difficult to understand.

Abstract: The problem statement is missing and the objective of the paper is unclear. The authors may want to add 1-2 lines to describe how the output of this research could improve the recovery from leachate solution, as this is mentioned in the title but not in the abstract. Perhaps a problem statement that focuses on the difficulties in recovering REEs from leachate solutions can be emphasized together with the objective of this paper.

Abstract: Where is pH0 4 coming from?

Abstract: What do you mean by a “U recovery”?

Abstract: These results make the sorbent as a promising in the field of metal valorization - a promising of (what)?

Abstract: The novelty of this study is not mentioned.

Line 94, “…under UV emission UV and…”  should be replaced with “..under UV emission and...”

Line 137, incomplete sentence.

It is good to show TEM & SEM analysis for magnetite chitosan nanoparticles (MCH).

Line 375, Section 3.3 Application on ore leachate. While in Line 440, there is another Section 3.3

Content in 2. Results and Discussion is jumbled up with content in 3. Materials and Methods. Materials and Methods should come first before Results and Discussion.

Table 5 is repetitive with different contents.

 

 A massive amendment is required for this paper as the oral presentation is untidy. 

Author Response

RESPONSE to REVIEWER#4

Red: Specific response to Reviewer comment.

Blue: New statement added to the revised manuscript

First, we would like to thank the reviewer for his/her time consumed in the deep reviewing of the paper and for their instructive and meaningful comments.

 

Review Report Form

Open Review

( ) I would not like to sign my review report
(x) I would like to sign my review report

Quality of English Language

( ) English very difficult to understand/incomprehensible
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I am not qualified to assess the quality of English in this paper

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	( )	(x)	( )
Are all the cited references relevant to the research?	(x)	( )	( )	( )
Is the research design appropriate?	( )	( )	(x)	( )
Are the methods adequately described?	( )	( )	(x)	( )
Are the results clearly presented?	( )	( )	(x)	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

Abstract: Please rephrase the first sentence as it is very difficult to understand.

Thanks for the comment, we improve this sentence as follow:

Successive grafting of new sorbent bearing amino phosphonic groups based on chitosan nano magnetite particles through coupling with formaldehyde.

Abstract: The problem statement is missing and the objective of the paper is unclear. The authors may want to add 1-2 lines to describe how the output of this research could improve the recovery from leachate solution, as this is mentioned in the title but not in the abstract. Perhaps a problem statement that focuses on the difficulties in recovering REEs from leachate solutions can be emphasized together with the objective of this paper.

Thank you for alerting. We revised the abstract and try best to improve it and clarify the novelty of the work.

This sentence was added

The sorbent was used for REEs recovery from leach liquor residue after pretreatment for extraction of some interested elements. From these results (high loading capacity, fast kinetics, high selectivity and stable against acid treatments), it makes the sorbent as a promising tool for selective recovering of rare earth elements in the field of metal valorization.

Abstract: Where is pH0 4 coming from?

The optimization of Nd(III) sorption during studies of the pH effects (section 2.2.1), shows the high sorption was achieved at pH₀ 4. The studies were performed at different pH values (1-6) and the sorbent appears a high sorption performances at pH₀ 4

Abstract: What do you mean by a “U recovery”?

Thanks for alerting, we mentioned this work for descripting the dissolution from ore materials and extraction by sorbent to get it in the final form of the yellowcake precipitation. This is because this solution was provided from the mining area after treated for uranium extraction.  

Abstract: These results make the sorbent as a promising in the field of metal valorization - a promising of (what)?

We mean by this sentence that the sorbent can be used in the extraction of the REEs with highly efficient comparing to the other alternative sorbent. This is derived from the high sorption capacities, fast kinetics, selectivity and stability.

This sentence was added

From these results (high loading capacity, fast kinetics, high selectivity and stable against acid treatments), it makes the sorbent as a promising tool for selective recovering of rare earth elements in the field of metal valorization.

Abstract: The novelty of this study is not mentioned.

Thanks for alerting, we revised it and try best to improve the quality and novelty.

Line 94, “…under UV emission UV and…”  should be replaced with “..under UV emission and...”

Thanks for alerting, it was corrected

Line 137, incomplete sentence.

Thanks, it was revised and corrected

It is good to show TEM & SEM analysis for magnetite chitosan nanoparticles (MCH).

Thanks, it was provided in the revised version

Figure 4. TEM and SEM analyses of MCH (a and b) and CH-POH (c and d) sorbents

Line 375, Section 3.3 Application on ore leachate. While in Line 440, there is another Section 3.3

Thanks, it was corrected

Content in 2. Results and Discussion is jumbled up with content in 3. Materials and Methods. Materials and Methods should come first before Results and Discussion.

Thanks for alerting, but this is according to the instruction of the journal that make the results and discussion as the second section after introduction followed by Materials and Methods, it is out of our control

Table 5 is repetitive with different contents.

 Thanks for alerting, but this is the constituents (metal ions) in the solution and the extraction % of each metal after treatment.

 A massive amendment is required for this paper as the oral presentation is untidy. 

Thanks for alerting, we carefully checked the Editing (typing and grammar). We hope the revised version is meaningful and making the manuscript readable.

Finally, we appreciate the efforts that done by the reviewer and hope this revised version makes the data more readable and understandable.

 

 

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear editor

The authors have improved this manuscript, however several recommendations were not followed:

1. A lot of self citations, which is not ethical. Please leave the three more relevant references. I will not accept more than three references (self citations).

2. Fast kinetic is not appropriate for 20 min. The conception and design of industrial reactors require very short time (some seconds). Twenty min. is too long time to be upscaled to an industrial system. Please change this term "fast kinetic" in your text

Author Response

RESPONSE to REVIEWER#1

Red: Specific response to Reviewer comment.

Blue: New statement added to the revised manuscript
First, we would like to thank the reviewer for his/her time consumed in the reviewing of the paper and for the instructive and meaningful comments.

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

Quality of English Language

( ) English very difficult to understand/incomprehensible
( ) Extensive editing of English language and style required
(x) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I am not qualified to assess the quality of English in this paper

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	(x)	( )	( )
Are all the cited references relevant to the research?	( )	(x)	( )	( )
Is the research design appropriate?	( )	(x)	( )	( )
Are the methods adequately described?	( )	(x)	( )	( )
Are the results clearly presented?	( )	(x)	( )	( )
Are the conclusions supported by the results?	( )	(x)	( )	( )

Comments and Suggestions for Authors

We try best to fix the English language and grammar, precising the discussion, support more information in the introduction and provide references of the discussion.

Dear editor

The authors have improved this manuscript, however several recommendations were not followed:
1. A lot of self citations, which is not ethical. Please leave the three more relevant references. I will not accept more than three references (self citations).

Thanks, we remove as much as possible of the self-citation and hope the revised version of the manuscript being suitable now
2. Fast kinetic is not appropriate for 20 min. The conception and design of industrial reactors require very short time (some seconds). Twenty min. is too long time to be upscaled to an industrial system. Please change this term "fast kinetic" in your text

Done, it was removed

Author Response File: Author Response.pdf