Treatment of Infectious Waste through the Application Rotary Kiln Incinerators and Ozone Technology

Round 1

Reviewer 1 Report

The authors have greatly improved their manuscript according to the first round review comments. This reviewer think it can be accepted for publication now.

Author Response

Thanks for your review.

Reviewer 2 Report

The paper by Khannam entitled "treatment of flue gas from an infectious waste by applying rotary kiln incinerators to ozone technology is a study on flue gas treatment. Authors examined flue gas treatment with ozone technology. They used ozone water to remove gas pollutants in exhaust gases. Results shows the treatment succeeded to reduce gas pollutants compared with non ozone system.

Comments:

1.The purpose of this manuscript is not clear. because  Flue gas treatment using ozone has been already examined and review paper is available. (for example, Lin et al. Chem. Eng. J. (2020) 382 p123030 https://doi.org/10.1016/j.cej.2019.123030).  Especially, Q. Ma et al. reported the application of ozone treatment with wet scrubber in the  Kiln Furnace.Energy Fuels 2016, 30, 3, 2302–2308. Unless authors state their purpose compared with previous research above at least, readers would not follow the novelty of this manuscript.

2. Although ozone water treatment succeeded to reduce gas pollutants, authors have not mentioned its mechanism. Other previous research using ozone treatment mentioned its mechanism. Author can find chemical mechanisms which can explain their results in previous researches.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors, I have a number of important remarks to you, namely:
1. The list of references is too small for such a significant problem. It is necessary to revise the sources for the relevance of the information; publications have been submitted for more than 10 years.
2. In the tables, the value of indicators must be given in a single form, namely, rounded to the active, or to hundredths.
3. The annotation needs to be made more informative.
4. In general, waste disposal by incineration is a rather old and ineffective method. Combustion products have a bad effect on service personnel. How this issue is being resolved.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

The article “Treatment of an Infectious Waste by Applying Rotary Kiln Incinerators to Ozone Technology” is interesting but in my opinion it must be rewritten before publishing, the authors should be able to handle this without any problem. Lack of line numbering makes it difficult to review the article.

Please use native speaker to improve English language.

Abstract:

Please do not use abbreviations like N/D in your abstract. Maybe you should attach more detailed results in your abstract.

Keywords

Just add one more-“standards”

Introduction

This part of your article should be rewritten. A better review of the data and literature on infectious waste not only in Thailand is needed. Just give greater overview (literature, companies, etc.) on waste incineration technology and use of ozone in environmental engineering please.

At the end of the introduction chapter, please state clearly what the scientific and practical aim of the presented research and article was

Material and methods

First give short information and table 1 as: Basic parameters of infectious waste rotary kilns incineration.

 Maybe you should write about improvements to the incinerator system using table? For example give the reason of changes-solution and result.

Give the reference of figures 1 and 2.

Chapter 2.2

Please give chosen specific parameters of ozone system in table, it will be clearer to understand figure 2.

Table 2 What about detection limits for other indicators?

Results and discussion

In this chapter please give only results. Some of the information in this chapter should go to Material and methods chapter.

Table 3- use only abbreviations e.g. Hg, Pb, Cd………

I do not understand information under the table N/D. I cannot see any N/D in your table, just check it please.

Please give broader discussion of figure 3.

Conclusion- or better conclusions

This is very important chapter. You must definitely extend it. Just give some specific results from the chapter Material and methods.

References

You should improve your article extending chapter Introduction. Also you can improve discussion of results. Use more references in your article please.

Author Response

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Author Response File: Author Response.pdf

Reviewer 5 Report

The work concerns the study of infectious waste incineration in a rotary kiln. The authors investigate the effect of the added ozone on the emission of pollutants from the combustion installation. The topic is important and interesting from the point of view of environmental protection. However, the manuscript looks more like a research report than a scientific article. There is no scientific explanation of how O₃ reacts with combustion substrates. The obtained pollutant emission result is satisfactory, but how can it be interpreted if the authors did not report the oxygen concentration in the exhaust gas. Experimental studies are not replicable unless excess combustion air is reported. I recommend that the article be scientifically supplemented with an explanation of the reactions taking place, the specification of the speciation forms of Cd, Pb and Hg in the exhaust gas, and the addition of information enabling the replication of the experiment.  
Check also Table 1: „Chamber combustion 2” maybe Chamber combustion 3?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 5 Report

The authors responded my comments very well, and the manuscript was improved in a good way. I think this paper can be considered to accept.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

This manuscript concentrated on the treatment of flue gas from an infectious waste by applying rotary kiln incinerators by ozone oxidation. Based on the proven flue gas treatment technique route, the addition of ozone facilitated the deep removal of several typical pollutants, i.e. Hg, NO₂, and SO₂, which was suitable for practical application and could solve the practical problems in flue gas further treatment to cope with such serious policies in recent years. However, this manuscript is not perfect enough, which should be carefully revised before published in Technologies.

1. Numerous investigations have reported flue gas treatment by ozone and achieved excellent efficiency. What is the main innovation of this manuscript? The significant importance of this study should be further emphasized in the introduction section. The manuscript is lack of description of environment significance at last paragraph.
2. In section 3, the author only provided the removal efficiency of the pollutants, including Hg, Pb, Cd, HF, TSP, SO₂, NO₂, CO, HCl. However, no discussion illustrated the final products. The products distribution analysis might be quite significant for this investigation which should be added in this manuscript.
3. This manuscript investigated the removal of various inorganic pollutants by ozonation, while there are still existing organic pollutants in flue gas, such as VOCs, PCDD/Fs. Several works have proved the superiority of ozone for VOCs efficient degradation (Environmental Science & Technology 55 (5), 3341-3351, Chemical Engineering Journal 426 (2021) 130814, Chemical Engineering Journal 427 (2021) 130929, Journal of hazardous materials 391 (2020), 122218, Applied Catalysis B: Environmental 266 (2020), 118662), whether the author conducted any evaluation about this? Some discussion should be added in the revised manuscript.
4. For the comparison of the effects of ozone addition on pollutants removal efficiency, the author conducted 0%, 7% and 15% ozone addition, respectively. Although it has achieved considerable removal efficiency, the consumption of ozone is very high. From the perspective of practical application, the energy consumption and operating cost analysis must be evaluated. Besides, how about the ozone residual.
5. Ozone was mixed with water before entering into flue gas, right? Do you consider the ozone decomposition in water? Have you considered the effect of temperature on oxidation efficiency?
6. Is it possible to present the results during long-term operation?
7. More related references should be added (Chemical Engineering Journal 382 (2020), 123030-123059, Fuel Processing Technology 88 (8)2007, 817-823, Energy & fuels 20 (6) 2006, 2432-2438), and some typos and grammar mistakes should be corrected.

Reviewer 2 Report

The paper by Khannam entitled "treatment of flue gas from an infectious waste by applying rotary kiln incinerators to ozone technology is a study on flue gas treatment. Authors examined flue gas treatment with ozone technology. They used ozone water to remove gas pollutants in exhaust gases. Results shows the treatment succeeded to reduce gas pollutants compared with non ozone system.

Comments:

1. Although ozone water treatment succeeded to reduce gas pollutants, authors have not mentioned its mechanism, which should be discussed.

2. Flue gas treatment using ozone has been examined and review paper is available. (for example, Lin et al. Chem. Eng. J. 2020 https://doi.org/10.1016/j.cej.2019.123030.) Authors should compare with efficiency of author's method with previous ozone treatment methods. And should state a merit and de-merit of their technique.