Development of Technology for the Bioleaching of Uranium in a Solution of Bacterial Immobilization

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Introduction

- What are the objectives of the study? There are nowhere to be found.

- While the literature review are lengthy, it is literally the explanation on the previous studies. There is no mention about the research gap that you've found and subsequently, no mention about the novelty of the study that you are undertaking currently.

- The first 4 paragraphs should be referred to any related references.

Methodology

- The methodology section should be divided into sub-sections, and for each sub-section, more elaboration is needed. The existing explanation is insufficient.

- Please include the diagram of the individual bioreactor configuration.

Results & Discussion

- Severe insufficient discussion of the findings. Please elaborate the findings.

- The contents need to be divided into sub-sections.

Abstract

- The abstract does not reflect the discussion presented in the manuscript. Please rewrite the abstract accordingly.

Title

- The title is too general. Please rephrase the title and make it more specific.

 

Comments on the Quality of English Language

Moderate editing required

Author Response

Hello, we are sending you a revised version of the article. If you are satisfied with the answers to the reviews, we would like to give you an English translation in MDPI

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The article titled 'Investigation of the rate of oxidation of ferrous iron by bacteria' fits well into the profile of the Applied Sciences journal and has the potential for implementation research. In the manuscript, the authors discussed the issue of stabilizing the growth of bacteria oxidizing iron ions on immobilizing media. In the Introduction, the authors indicated the current state of knowledge, focusing on microorganisms with specific properties. but the purpose of the work was weak.

 

Point 1 - Please clarify the research goal and describe it in 2-3 sentences at the end of the Introduction section.

The Authors demonstrated a strong relationship between the uranium content and pH in the production solution. The rate of oxidation of iron II ions increases with the use of an immoblizer, the wood chips used provide a large surface for microorganisms.

The authors clearly indicated the possibilities of using the technology, e.g. in the extraction of metals from ores, as well as in wastewater treatment processes. In the Discussion section, the authors describe important issues regarding the usability of the tested technology. However, there is no reference here to the results of other authors.

 

Point 2 - in the Discussion section, it is worth referring at least to a short comparison of the properties of several natural materials used in immoblization by bacteria, by other authors - What properties did they have/what effectiveness did they show compared to wood chips?

 

In the Introduction, the authors focused on microorganisms, in the Discussion you can focus on material properties. Especially since the Special Issue ''Sustainable Materials and Waste Recovery'' should focus strongly on the possibilities of using materials such as wood chips.

Author Response

Hello, we are sending you a revised version of the article. If you are satisfied with the answers to the reviews, we would like to give you an English translation in MDPI

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

General Comments:

The manuscript titled “Investigation of the rate of oxidation of ferrous iron by bacteria” has discussed the utilization of various immobilizer materials to facilitate bio-oxidation by Acidibacillus ferrooxidans. The topic is interesting to the readership of the journal as it could be broadly applied in the mining industry. However, the manuscript needs to be extensively improved as certain important information is missing. For instance, the introduction section does not sufficiently discuss the importance of ferrous ion oxidation to ferric ions in the Uranium mining process. And neither does it explain what leaching solution and productive solution are. Introduction does not specify the novelty of the research, the goals/objectives, or the research hypothesis. The Methodology section also needs to be improved by providing more details of the flow bioreactor operation. The Results and discussion section needs to be expanded adding more discussion on similar results obtained by previous studies. I do not recommend this manuscript for publication at this status and suggest revising/improving it. Specific comments are listed below.  

 

Specific comments 

 

Section	Comment
Introduction	Suggest adding more details on why oxidation of ferrous ions is important, what its impact on uranium mining, etc.
L50	More explanation/details about bio-leaching process/mechanism would be nice as it is mentioned multiple times later in the texts
L58	Immobilizotors? Or immobilizers?
L66-88	Suggest expanding the literature discussion here. This section does not seem to provide sufficient information related to the topic discussed. Sentences look incomplete as they do not provide sufficient information. Suggest reorganizing this section with more discussion relevant to the topic
L66-108	Use “et al” rather than writing the names of all the authors when citing a paper.
L109	Highlight the novelty, goals, objectives, and research hypothesis of the current study
L115, 122-123	Recommend providing manufacturer details for all instruments if available
L116-117	Either provide a reference or list constituents used in the medium
L126 -127	Specify the spectrometric method
Method section	Need to be organized in a methodical way. Certain important details are missing: flow rate of the flow bioreactor, residence time, how the samples were collected for analysis, and initial water quality of water subjected to treatment both in laboratory scale and pilot scale studies.
L169	Missing “by” before the name of the bacteria strain
Table 1	I find it difficult to understand why the minus value is given for material size. To effectively utilize space “H” and “D” that denote height and diameter can be removed as it is already given in the first column and the units can be indicated in the first column
L185	To better understand and compare it would have been better to include an SEM image of chips without iron hydroxide coating.
Table 2	Does “,” decimal point?
L211	What is the difference between the leaching solution and the productive solution? The word “productive solution” appears here for the first time and difficult to understand what it means. Please provide major water quality details of the two solution
L213	Research hypotheses haven’t been mentioned previously.
	Discussion and results are not sufficient. No comparison with the literature.
L237	Please specify what efficiency is high.
L248-250	References are needed as it is not experimentally tested in the current study

Comments on the Quality of English Language

English language needs moderate improvement. For instance, certain sentences in the methodology section look informal and incomplete.

Author Response

Hello, we are sending you a revised version of the article. If you are satisfied with the answers to the reviews, we would like to give you an English translation in MDPI

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Introduction 

- Yellow highlighted parts - Needs grammatical check and paraphrasing.

- This is not the way how introduction should be written. The introduction should be brief yet complete and informative. This introduction is just too long and redundant. Please rewrite the Introduction.

- Line 37-126 - There is almost no reference cited in all these para.

Results & Discussion

- Seriously insufficient for the publication in this journal.

 

 

Comments on the Quality of English Language

English editing is required

 

Author Response

Author's Reply to the Review Report (Reviewer 1)

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The majority of the previous concerns have been adequately addressed by the authors. 

A few additional comments are listed below:

1. Lines 136- 146 are lines 434 -444 are repetitive. (copy-paste)

2.  Values in Table 2 and Table 3 need to be revised for clearer presentation. Suggest replacing "comma" with "decimal point"

 

 

 

Comments on the Quality of English Language

The English language needs moderate improvement. For instance, certain sentences are incomplete and informal. 

Author Response

Author's Reply to the Review Report (Reviewer 3)

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Insufficient discussion.

Comments on the Quality of English Language

English editing is required.

Author Response

Author's Reply to the Review Report (Reviewer 1)

Author Response File: Author Response.docx