Municipal Solid Waste Composition and Generation with Emphasis on Plastics in Nablus City, Palestine

Round 1

Reviewer 1 Report

Landfill is an important way to deal with the problem by dispose of municipal solid waste (MSW) in developing countries, and the composition of MSW will affect the composition and the yield of leachate, as well as the production rate of greenhouse gases such as methane. Waste classification and statistics are often time-consuming and laborious, but this work is the basis of engineering technical analysis in many landfills, so this work is still valuable. From the manuscript, the technical or academic nature of the whole work is not strong enough, and the analytical methods used are conventional and lack of in-depth discussion. Generally, the manuscript does not show further study on the basis of previous studies, or the innovation of the work is not that strong. Fortunately, the manuscript put emphasis on the component content of the type of plastic in the regional waste of Nablus City (e.g., PET, PP, HDPE, et al.). It is suggested to add more reference related to the plastic in the MSW in the introduction section, so as to enhance the academic value of this paper. In view of the complexity and difficulty of this work, I would like to give the authors a chance to revise it thoroughly.

Author Response

Thank you for your comments and the understanding of the complexity of the conducted work.

The manuscript was enhanced to highlight the objectives of the work and its novelty (lines 107 – 117)
Furthermore, a section about the need to understand the plastic waste fraction and the situation in the state of Palestine was added to give the reader a better understanding to the experimental work and its implications. See lines 76 – 117.

Furthermore, a completely new imperial section was added to show the possibility of applying the generated data (384 – 468) .

Reviewer 2 Report

The paper, while having a good structure, has significant deficiencies, that must be addressed.

The introduction deals with many major issues and provides means to understand the paper. However, the following must be changed.

1. The study does not seem to provide a significant contribution. The authors must emphasize and make clear what is the contribution of the study to what we already know. They must include this contribution in both introduction and abstract. The phrase 'it is recommended...' should be replace with a phrase that clearly indicates the findings and what they imply for Palestine and OTHER countries with similar characteristics. Providing just statistical data for an area, does not constitute a research worth publishing.

2.The authors must replace the acronyms in the abstract, by the meaning they have . Eg MSW, HDPE etc, must not be used in abstract, and must be replaced by their full meaning (municipal solid waste etc) unless they are first explained there. On the contrary, the main part of the study, does not need alterations regarding this.

3. Discussion made in CHAPTER 3 must be explained with info regarding the cities and areas involved. Why the composition of waste for example is different in the one area from the other.  Is it because there is different mix of production facilities, is it because because there is different population characteristics, or for other reasons? the authors, must inform us, and connect it with the study clearly, based to published studies that provide the source of inference.

4. Conclusion is not clear, has to be completely rewritten.

5. An empirical part is missing. The authors will supposedly 'to propose optimized waste management scenarios', but it is not clear based on what equations, and findings, the conclusions are drawn. the authors must add a sepaprate chapter where they will show clearly (with equastions) their model, and the tables of their findings.

 

 

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Author Response

“The paper, while having a good structure, has significant deficiencies, that must be addressed.

The introduction deals with many major issues and provides means to understand the paper. However, the following must be changed.

1. The study does not seem to provide a significant contribution. The authors must emphasize and make clear what is the contribution of the study to what we already know. They must include this contribution in both introduction and abstract. The phrase 'it is recommended...' should be replace with a phrase that clearly indicates the findings and what they imply for Palestine and OTHER countries with similar characteristics. Providing just statistical data for an area, does not constitute a research worth publishing.

The contribution of this research is to understand the characteristics of the MSW stream that is mostly ending up in landfills and illegal dumpsites, which will aid in (I) understanding the local behavior in consumption and waste disposal (II) propose solutions of waste minimization and enhanced EOL treatment scenarios. This was emphasized as recommended in the abstract and introduction of the study.

See lines: 28 – 39 and 107 - 117

The phrase ‘is it recommended’ was removed providing a stronger implication to the proposed solutions.  

2.The authors must replace the acronyms in the abstract, by the meaning they have . Eg MSW, HDPE etc, must not be used in abstract, and must be replaced by their full meaning (municipal solid waste etc) unless they are first explained there. On the contrary, the main part of the study, does not need alterations regarding this.

Thank you for your comment, this was improved in the text.

3. Discussion made in CHAPTER 3 must be explained with info regarding the cities and areas involved. Why the composition of waste for example is different in the one area from the other. Is it because there is different mix of production facilities, is it because because there is different population characteristics, or for other reasons? the authors, must inform us, and connect it with the study clearly, based to published studies that provide the source of inference.

The reason of composition variations was explained in text and made clear for the reader. Kindly see:

Lines 244 – 246

Lines 270

Lines 277 - 283

4. Conclusion is not clear, has to be completely rewritten.

The conclusion was re-written as per the suggestion.

5. An empirical part is missing. The authors will supposedly 'to propose optimized waste management scenarios', but it is not clear based on what equations, and findings, the conclusions are drawn. the authors must add a sepaprate chapter where they will show clearly (with equastions) their model, and the tables of their findings.

Thank you for the insightful suggestion. An empirical application of the data was done in a new section. See lines 384 – 468 

Reviewer 3 Report

This manuscript investigated the composition of municipal solid waste and source of plastics in Nablus City. The introduction is well structured and fully demonstrates the purpose and importance of this study. However, the amount of data presented in the Results and Discussion was insufficient to support the framework of the discussion. In my opinion, this manuscript can be accepted by Sustainability after minor revisions.

1. The author categories Nablus into five districts with different characteristics, but the detailed data related to municipal solid waste, such as population, area, GDP and etc. in those five districts are not provided.

2. How about the production of municipal solid waste in those five districts?

3. It would be interesting to analyze the relationship between the composition of municipal solid waste and the relevant data in those five districts.

4. In line 50, wrong reference“[2], 9]”.

5. In Figure 3, the color of group Al-Makhfia is different from other groups, dose it means something special?

6. In line 193, why Al-Makhfia showed the highest generation for polymers PET and HDPE, and Al-Masakin Al-Shaebia showed the lowest generation?

7. In Figure 8, is the unit of Amonut (Mg/a) suitable?

Author Response

1. The author categories Nablus into five districts with different characteristics, but the detailed data related to municipal solid waste, such as population, area, GDP and etc. in those five districts are not provided.

The characteristics of the different districts were provided in Table 1. Specific data like population number of GDP are not to be easily obtained, especially that there are no statistical studies differentiating these districts. However, their selection was based on their location (to cover the city from east to west) and based on the knowledge of the authors regarding the different construction structures (buildings, villas, houses, etc.) in addition to the average income (low, middle, or high). This information is provided in the table through the description of each of these districts.

However, an image to the selected points was added to help the reader to see the coverage of the city.

2. How about the production of municipal solid waste in those five districts?

There is no available data in the Nablus municipality for each and every district. They consider the city as a whole unit. The distribution of waste samples between the districts was done by the authors for scientific purposes, to insure the coverage of different locations, behaviors, etc.

3. It would be interesting to analyze the relationship between the composition of municipal solid waste and the relevant data in those five districts.

The composition between the different regions is quite similar. However, there were explanations provided to understand the reasons for the minor differences (e.g. structure, services, average income, etc.). Please see lines:

244 – 247

270

277 – 283

4. In line 50, wrong reference“[2], 9]”.

The reference was checked once more, and this information is based on what reported in the mentioned publication.

As quoted:

“Reliable waste management data provides an all-inclusive resource for a comprehensive, critical and informative evaluation of waste management options in all waste management programmes (Chang and Davila, 2008, Hancs et al., 2011, Qdais et al., 1997). Unfortunately, these required fundamental statistics are lacking in many developing countries (Buenrostro et al., 2001) and where they are available, they are inconsistent because they come from many sources which cannot be validated and are sometimes based on assumptions but not scientific measurements (Couth and Trois, 2011, IPCC, 2006, Ranjith, 2012).”

5. In Figure 3, the color of group Al-Makhfia is different from other groups, dose it means something special?

Thank you for your question! The different color is to highlight the discussion part about why this area has higher fraction of organic waste. However, since this is already explained in the discussion, the color was changed to make it uniform with all other regions.

6. In line 193, why Al-Makhfia showed the highest generation for polymers PET and HDPE, and Al-Masakin Al-Shaebia showed the lowest generation?

Thank you for the constructive feedback, this was enhanced in the text, lines 277 – 283

“The high composition of PET and HDPE in Al-Makhfia and in Al-Amiria is due to their residential structures and the less commercial activities, indicating higher consumption of household products (higher consumption of packaged products). Al-Masakin Al-Shaebia has large commercial complex of restaurants and malls. In addition to the schools and the college of technology. Hence, the product consumption behavior is different, resulting in higher fractions of LDPE films (as shopping bags), and the presence of PVC fraction, which could originate from the car repair shops in the area.”

7. In Figure 8, is the unit of Amonut (Mg/a) suitable?

Mg or tonnes should be interchangeable. Since the reviewer has concerns, the unit was changed to tonnes.

Reviewer 4 Report

The manuscript entitled "Municipal Solid Waste Composition and Generation with Em- 2 phasis on Plastics in Nablus City, Palestine" was a good attempt to quantify the different fractions and to propose optimized waste management scenarios in Palastine. 

In the conclusion part the authors mentioned "The analysis of the polymeric composition of the plastic waste fraction showed that the LDPE films are the most dominant fraction. This is due to the unregulated consumption of plastic films (in form of bags) in the country". The authors are recommended to explain further.

Author Response

Thank you for your comment1 The conclusion part was edited to give clearer indication to the outcomes of the study. Further explanation about the polymeric distribution was also provided.

Round 2

Reviewer 1 Report

The readability has been improved in the revised manuscript.  I suggest formatting and modification before publication. 

Author Response

Dear Reviewer, 

The manuscript was proof-read and the formatting and language correction was conducted. 

Kindly check lines:

50, 60, 153-154, 224-232, 253-256

Also section 3.4 was merged into section 3.3

Figure 11 was removed as it was not very relevant

The conclusion was fully edited to amke it more readable and concise. 

Reviewer 2 Report

The authors made serious efforts to improve their study. They rewrote the abstract, the inroduction and other parts. However the authors did not yet rewrote the paper to an extent that they provide evidence of  significant contribution of their study to whatever we already know.

This contribution must be very well written and must emphasize how this study can be useful to address things we did not knowm, and can be useful for other areas or markets.

 

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Author Response

Thank you for your comments.   Regarding the significant contribution of our study, we'd like to emphasize that our research fills a marked gap in the existing literature. As pointed out in lines 103-105 of our manuscript.

Furthermore, our study doesn't merely add another piece of information to what we already know, but instead provides foundational data on the post-consumer plastic waste composition and formats in Palestine, which, to our understanding, is a novelty in the current literature.

To better emphasize this unique contribution, we have worked on enhancing our introduction and conclusion sections to stress the broader implications and significance of our study in the context of the existing body of knowledge.

Additionally, this study proposes the consideration of a centralized recycling system, where the recyclables and organic waste fractions are collected separately from the main cities in the northern part of the west bank and sent to the waste treatment facilities. Based on the proposed case-study (section 4), potential of recycled material was considered, and hence, the capacity of the recycling facilities could be estimated. This in itself is a significant part of this research, which was added based on the reviewers recommendations.

The language and readibility of the manuscript were enhanced in this revision.