Distribution Characteristics of Typical Heavy Metals in Sludge from Wastewater Plants in Jiangsu Province (China) and Their Potential Risks
Round 1
Reviewer 1 Report
I revised the manuscript “Distribution characteristics of typical heavy metals in sludge from wastewater plants in Jiangsu Province (China) and their potential risks” submitted to the Water.
The authors presented the topic on the contents of heavy metals pollutants in sewage sludge from WWT. Furthermore, authors currented approaches to sewage sludge management into circular bioeconomy and potential risks by pollutants. The topic of the article is up to date, the introduction is easy detailed. This problem is relevant for journal scope.
The concept and aim are clearly defined. The presentation and discussion of the presented topicis clear and very detailed.
Other weaknesses to be corrected:
-Keywords should be in alphabeti-cal order.
-Please follow the list of abbreviations. The authors use acronyms, e.g. UCT, MBR, CAST, CASS, UNITANK etc.
The manuscript follows the formal regulations of MDPI journals.
I suggest the acceptance after minor revision.
Author Response
Dear reviewer:
Thank you for your decision and constructive comments on my manuscript. We have carefully considered the suggestion of Reviewer and make some changes. We have tried our best to improve and made some changes in the manuscript.
- Keywords should be in alphabeti-cal order.
Responds: Thank you for your correction, we have completed the correction according to the Reviewer’s comments.
- Please follow the list of abbreviations. The authors use acronyms, e.g. UCT, MBR, CAST, CASS, UNITANK etc.
Responds: Thank you for your correction, we have completed the correction according to the Reviewer’s comments.
Special thanks to you for your good comments.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The current manuscript is a repeated type of work with several previously published case studies.
I do not know why did authors write the introduction part using the past tense. I made this section confusing.
In methodology, there is a need the information like sampling time and frequency, number of samples etc.
The result section is ok but the discussion part should be improved.
The conclusion section must be rewritten with future recommendations.
Author Response
Dear reviewer:
Thank you for your decision and constructive comments on my manuscript. We have carefully considered the suggestion of Reviewer and make some changes. We have tried our best to improve and made some changes in the manuscript. Revised portion are marked in red in the paper.
- The current manuscript is a repeated type of work with several previously published case studies.
Response: I am sorry that original manuscript of our paper does not make clear the novelty and importance; In view of this, we have strengthened the introduction to highlight innovation. This paper is based on a research sampling of sludge throughout Jiangsu province to evaluate the heavy metals in Jiangsu province-wide sludge, and adds gaps to the effects of different processes on sludge heavy metals in different regions for other researchers to use as a reference basis.
- I do not know why did authors write the introduction part using the past tense. I made this section confusing.
Response: I'm sorry that there are some syntax errors in the Introduction, which has been corrected. In addition, the past tense content used in Introduction is a literature review, is the content of others have completed the elaboration.
- In methodology, there is a need the information like sampling time and frequency, number of samples etc.
Response: The sludge collected was dewatered sludge from the wastewater plant before it was shipped out, and was mixed using multi-point sampling, or in the case of multiple filter presses working at the same time, it is sampled and mixed at each filter press. Sampling on each filter press was done by taking approximately 200g of sludge every 1min on the conveyor belt and mixing it 10 times in a row. Samples were repeated six times at each treatment plant, with a sample mass greater than 1 kg to ensure that the total amount of samples was sufficient to support the subsequent experimental unfolding. The collected sludge was packed in clean and dense bags or polyethylene bottles and stored temporarily in an insulated box, and subsequently stored under refrigeration and sealed at 4°C. Sam-ples were collected in December 2021.
- The result section is ok but the discussion part should be improved. The conclusion section must be rewritten with future recommendation
Response: Thank you very much for your comments. Based on the results of the assessment of heavy metals of sludge in Jiangsu province, we can consider the reuse of its non-organic fraction for building materials, and the feasibility of building materials can be evaluated in the future; in addition, since sludge toxicity is related to its morphology, we can consider the study of the influence of different factors on sludge morphology and toxicity in the future.
Special thanks for you for your valuable comments and Suggestions!
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Although the authors addressed some of the points, there is still a need for significant improvements in the manuscript before its publication.
1. I do not agree with the modifications done in the introduction part. It should be revised thoroughly to make a clear sense and to generate a hypothesis.
2. Discussion part should further be updated with proper and recent citations. The authors must try to compare the results with the previously published papers.
3. The future prospects added in the conclusion section is clear to me.
Author Response
Dear reviewer:
Thank you again for your decision and constructive comments on my manuscript. We have carefully considered the suggestion of Reviewer and make some changes. We have tried our best to improve and made some changes in the manuscript. Revised portion are marked in red in the paper.
- I do not agree with the modifications done in the introduction part. It should be revised thoroughly to make a clear sense and to generate a hypothesis..
Responds 1 : We apologize for the lack of completeness of the first revision. We have completely revised the entire Introduciton section, and in this version we have reorganized the introdution content to produce clear sense and generate hypotheses.
- Discussion part should further be updated with proper and recent citations. The authors must try to compare the results with the previously published papers.
Responds 2: Thank you for your corrections. We have updated the new literature and eliminated the old ones, and the discussion sections have all been revised.
- The future prospects added in the conclusion section is clear to me.
Responds 2: Thank you for your approval, and we will keep this in mind in my subsequent research.
Special thanks for you for your valuable comments and Suggestions!
Best regards,
Mrs Xiao
Author Response File: Author Response.docx
