Combined Effect of Ferrous Ion and Biochar on Cadmium and Arsenic Accumulation in Rice

Round 1

Reviewer 1 Report

The research presented by the authors is interesting, but the English language and style hindrances its potential, making it hard to read and understand.

The discussion about As, Fe and Fe uptake by plant in the phytoremediation of mining soils can be enhanced. Please have a look to, for example, the paper entitled “Phytoremediation of highly contaminated mining soils by Jatropha curcas L. and production of catalytic carbons from the generated biomass” (Journal of Environmental Management, Volume 231, 1 February 2019, Pages 886-895).

Abstract, line 17: “Oryza sativa” should be in italic.

Abstract, line 19: “1BC-1Fe” should be described.

Page 1, line 43: Can the term “hypoxia” be used in this context?

Materials and Methods, line 70: Please provide a briefly explanation about the procedure of producing the biochar, and what was the raw material to produce it.

Materials and Methods, lines 114 to 121. Please rephrase this section and add more useful information about the chemical analyses.

Table 1: Please specify in the tittle what are TOC and CEC (as in line 77).

Table 2: I do not understand how the effective tiller number of, for example, control sample (CK), is 4.1±0.2. If there were 3 replicas, two of them had 4 tillers and the other 5 tillers, 4.1 tillers as mean cannot be achieved.

Figure 3. Should not be the figure caption as follow: “Available Cd and As in soils after treatments?

Lines 202-204, lines 236-237, lines 255-257: These statements should be experimentally supported or by comparison with the works of other authors, such as the abovementioned.

Line 214: absorbed?

Tables 3 and 4: Bioaccumulation factors (BF) and translocation factors (TF) of …

Lines 321 to 323: I am not sure whether this conclusion is well supported by the experimental results.

Some examples of English mistakes:

Line 36: “the rice take in more”

Line 37: “As it …. took” TAKEN

Line 45: “Biochar ……….. were effective” WAS

Line 52:  “There are numerous iron-based materials THAT have been”,

Line 53 and throughout the text: do not write arsenic with capital letter.

Line 129: “were digestion”.

Line 161: “Fe treated”, “the BC alone treated”.

Line 171: “although BC alone treated reduction the available Cd”.

Line 191: “plant are more susceptible to damage”.

Line 212: “Total As” (total should not be in capital letter).

Line 246: “which could be induces” INDUCED

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors,

I read the MS "Combined effect of ferrous ion and biochar on cadmium and arsenic accumulation in rice". This is an interesting research that describes a hot topic: coimmobilisation of As and Cd in paddies to ensure rice quality. The experimental work is interesting, timing and topical. Finally, the authors describe some combinations of Fe(II)+biochar amendments that are able to mitigate inorganic pollution in rice grains. But the MS needs extra work. Here you can find some general and specific comments that should be addressed in the next draft:

ABSTRACT:

Line 13-15, State here that As and Cd pollution in rice grain is a relevant exposure pathway for humans.

Line 23 and over all the MS: you sometimes use BC+Fe, others Fe combined with BC, others Fe and BC, FeSO4·7H2O combined with biochar (why 7H2O in interesting to name the treatment?), etc. Please select one notation and use it in the whole manuscript (homogenise terms).

Line 27, this is the first time it is shown the importance of the pH. Please bring some attention to it before in the abstract or delete, otherwise it appears suddenly.

KEYWORDS: In my opinion, you should include availability/phytoavailability, I would consider deleting rice tissue

INTRODUCTION:

Same experimental scheme has been used recently (Fresno, T.,... (2020). Aided phytostabilisation over two years using iron sulphate and organic amendments: Effects on soil quality and rye production. Chemosphere, 240, 124827.) but in aerobic crops (rye) with As and other metal (Cu), it may help in introduction and discussion.

Table 1. Change units of TOC from g/kg to %. In line 84, it may be helpful to state the limit of detection (mg/kg) of metals.

Line 87, it says w/w but later only says 9 kg soil. State the percentaje this implies (1%).

Line 91. State the number of replicates (pots) per treatment.

Line 123. Did you analyse Zn and Fe in the grains? It is another hot topic and your treatments may change the concentration of both in rice.

Figure 1 and thereafter, change CK by Control. Not sure what CK stands for in English.

In ALL the tables and figures give more details in captions/headings. When applicable, state that you show mean+-SE, show number of replicates (n). Also give a short description of the tratments (in brackets add the coding).

Line 188 and all over the MS. When you show SE in the figure/table, do not state in the text the same value. Text should be easy to read and having such pile of numbers does not ease it.

DISCUSSION

Discussion has a lot of typos, odd expression and mistakes, sometimes is diffucult to follow what the authors are expressing. For instance, Line 238-240 is very odd, you have to revise all this sentence. Line 250-251 it is the same. Line 255-257 as well. Line 259-263 the sentence is too long, badly connected and difficult to understand. Line 266-268 what studies are you meaning? what is a "basilic part"? Please revise all the discussion, I cannot revise properly this unless authors improve what is being said there and how they are writting the sentences. The work may improve a lot if the MS is revise by English scientific editors.

Conclusions, instead, are more clear and better written, but please try to shorten them if possible. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Authors have properly addressed my criticisms, so I do not have any other comment or suggestion about the technical part of the paper. Notwithstanding, the format and English style still need to be improved.

Author Response

Dear reviewer,

Thank you for your comments on our manuscript entitled “Combined effect of ferrous ion and biochar on cadmium and arsenic accumulation in rice”. (Manuscript ID: applsci-667211)

We appreciate your positive, constructive comments and suggestions which made great improvement on our manuscript. We have studied the review reports carefully and have made corrections according to reviewers’ suggestions. The English language and style have been edited extensively which we hope meet with approval. Revised portion were marked in red in the paper. The main corrections in the paper and the responds to reviewers are following:

We tried our best to improve the manuscript and made changes in the manuscript. These changes will not influence the content and the framework of the paper. All the revisions are highlighted using the “Track changes” function in Microsoft Word. We hope that the correction will meet with approval.

Once again, thank you very much for your comments and suggestions.

With best regards,

Rong Qun

Reviewer 2 Report

Line 98: transform limits of detection to ug/kg.

Author Response

Dear reviewer,

Thank you for your comments on our manuscript entitled “Combined effect of ferrous ion and biochar on cadmium and arsenic accumulation in rice”. (Manuscript ID: applsci-667211)

We appreciate your positive, constructive comments and suggestions which made great improvement on our manuscript. We have studied the review reports carefully and have made corrections according to reviewers’ suggestions. The English language and style have been edited extensively which we hope meet with approval. Revised portion were marked in red in the paper. The main corrections in the paper and the responds to reviewers are following:

Point 1. Line 98: transform limits of detection to ug/kg.

Response: Thank you for your suggestion. We have made a supplement of details about our sample analysis(L157-L158). Then the limits of detection were transformed according to the method of our analysis. The limits of detection were: As 0.025 mg/kg, Cd 0.0125 mg/kg (L112-L113).

We tried our best to improve the manuscript and made changes in the manuscript. These changes will not influence the content and the framework of the paper. All the revisions are highlighted using the “Track changes” function in Microsoft Word. We hope that the correction will meet with approval.

Once again, thank you very much for your comments and suggestions.

With best regards,

Rong Qun