Natural Treatment Systems and Importance of Social Cost Benefit Analysis in Developing Countries: A Critical Review

Round 1

Reviewer 1 Report

Review to „Natural Treatment Systems and Importance of Social Cost Benefit Analysis in Developing Countries: A Critical Review “

This study was conducted for pollutants removal overview performed in the Natural Treatment Systems (NTSs) as more appropriate wastewater treatment system in developing countries. "This search was carried out in EBSCOhost, Google Scholar and Web of Science database and Scopus.- maybe not needed to add here these sources.

Regarding to wastewater technologies, Bacterial enrichment cultures developed under optimized conditions including temperature , optimum pH and the lower maximum  growth condition than needed for cleaning need to be overviewed. The results should showed what bacterial consortia well developed under various conditions, as a  novel result

In Your research, there need to be given available wastewater treatment systems, MBR, MBBR, UASB, SBR as exapmles with references.

Parameters are given with too much accuracy, without standard error (+/-) 

Literature has shown a lot of similar studies on the BNR, more novelty is needed to be defined here. Microbial communities are dominated by anammox bacteria across various results. Therefore, it is highly desirable to establish and show data on the whole BNR microbial communities’ profiles at different process stages- Be more specific how bacterial quantities increase as fast as their doubling time enables.

Check whether for a wastewater samples taken from reactor, can normally the value of VSS be greater than the value of TSS?

Figure 1. Fig. 2. How come the figure is not involved graphical components, in present form not great look of figures is given.

Is it correct to give proportions of bacteria with using  specific primer sets and  Illumina sequencing?

Figures can be sharper, showing the detailed info with error bars.

Was there measured stable pH in overviewed period for bacteria. - what was stable ph with error estimations +-?

Following a comprehensive analysis of data, the results were promising.

After: „Developing countries follow the western nations’ traditional model of centralised wastewater treatment in many places. Add: nitrogen emission standards being increasingly strict, researchers are urged to devote themselves to development of novel high-efficient and economical technologies. “ Literature have shown different water treatments to be solved by economical way, which could be shown as: https://doi.org/10.1016/j.scitotenv.2021.149133, https://doi.org/10.3390/w13030350, https://doi.org/10.1080/09593330.2020.1721566

 

Author Response

Response to Review Comments

Comments and Suggestions for Authors

Review to „Natural Treatment Systems and Importance of Social Cost Benefit Analysis in Developing Countries: A Critical Review “

 

This study was conducted for pollutants removal overview performed in the Natural Treatment Systems (NTSs) as more appropriate wastewater treatment system in developing countries. "This search was carried out in EBSCOhost, Google Scholar and Web of Science database and Scopus.- maybe not needed to add here these sources.

 

Regarding to wastewater technologies, Bacterial enrichment cultures developed under optimized conditions including temperature , optimum pH and the lower maximum  growth condition than needed for cleaning need to be overviewed. The results should showed what bacterial consortia well developed under various conditions, as a  novel result

Response:

Thanks for reviewer suggestion. Our work focus on policy aspects of the Natural Treatment Systems and do not focus on micro-level experimental or bacterial work. However, we have still attempted to include the following.

Balcterial enrichment cultures can degrate Haloacetic acids (HAAs) frequently detected in surface waters and in drinking water distribution systems (McRae et. al., 2004).    Biomass containing Denitrifying polyphosphate accumulating organisms (DPAOs) maintained an efficient COD, nitrogen and phosphorus removal. Hence, it can be used for treatment of wastewater containing high nitrite and nitrate content (Zekker et. al., 2021).

 

In Your research, there need to be given available wastewater treatment systems, MBR, MBBR, UASB, SBR as exapmles with references.

 

Response:

Thanks for reviewer suggestion. Our work focus on policy aspects of the Natural Treatment Systems and do not focus on mechanized treatment systems. However, we have still attempted to include the following.

There are different biological methods for treatment of greywater including sequencing batch reactor (SBR), the membrane bioreactor (MBR), rotating biological contactors (RBCs), the moving bed biofilm reactor (MBBR), and the upflow anaerobic sludge blanket (UASB) (Khalil and Liu, 2021).  MBR is one of the most preferred alternative for wastewater recycling in high rise buildings  (Kalbar et. al., 2012) 

Up-flow Anaerobic Sludge Blanket (UASB) reactor, Final Polishing Unit (FPU) and Down-flow Hanging Sponge (DHS) system, treating municipal wastewater located at Dhandhupura, Agra, Uttar Pradesh (India) outperforms many other contemporary NTS technologies (Mazhar et. al., 2021). The treated water may be considered for cultivation, and safely discharged into water bodies

 

Kalbar (2021) suggest to involve hybrid treatment systems (HTSs) considering a combination of natural and mechanized treatment approaches for India. Adoption of HTSs would save energy and deliver environmental benefits.

Kalbar et. al. (2012b, 2016) proposes scenario-based multiple-attribute decision-making (MADM) methodology to include regional and local  societal priorities including environmental and economic perspectives to select appropriate technology.

 

 

Parameters are given with too much accuracy, without standard error (+/-)

Response:

Thanks for reviewer suggestion. It is not clear which parameter is being indicated. In general, we have not cited any parameter.  Our work focus on policy aspects of the Natural Treatment Systems.

Literature has shown a lot of similar studies on the BNR, more novelty is needed to be defined here. Microbial communities are dominated by anammox bacteria across various results. Therefore, it is highly desirable to establish and show data on the whole BNR microbial communities’ profiles at different process stages- Be more specific how bacterial quantities increase as fast as their doubling time enables.

Response:

Thanks for reviewer suggestion. Our work focus on policy aspects of the Natural Treatment Systems and do not focus on micro-level experimental or bacterial work.

Check whether for a wastewater samples taken from reactor, can normally the value of VSS be greater than the value of TSS?

Response:

We have not conducted any laboratory study and the work is based on literature review and mainly focus on macro level aspects of socio-economic benefits of NTSs.

 

Figure 1. Fig. 2. How come the figure is not involved graphical components, in present form not great look of figures is given.

Response:

We have produced the original figure

Is it correct to give proportions of bacteria with using  specific primer sets and  Illumina sequencing?

Response:

Thanks for reviewer suggestion. Our work focus on policy aspects of the Natural Treatment Systems and do not focus on micro-level experimental or bacterial work.

Figures can be sharper, showing the detailed info with error bars.

Response:

We have produced the original figure

 

Was there measured stable pH in overviewed period for bacteria. - what was stable ph with error estimations +-?

Response:

We have not conducted any laboratory study and the work is based on literature review and mainly focus on macro level aspects of socio-economic benefits of NTSs.

 

Following a comprehensive analysis of data, the results were promising.

 

After: „Developing countries follow the western nations’ traditional model of centralised wastewater treatment in many places. Add: nitrogen emission standards being increasingly strict, researchers are urged to devote themselves to development of novel high-efficient and economical technologies. “ Literature have shown different water treatments to be solved by economical way, which could be shown as: https://doi.org/10.1016/j.scitotenv.2021.149133, https://doi.org/10.3390/w13030350, https://doi.org/10.1080/09593330.2020.1721566

 

Response:

We have included the referred article.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper reviews the pros and cons of natural treatment systems, including the economic and social cost-benefit implications.  Before publication, the grammar and syntax of the paper should be reviewed and improved (particularly the consistency of verb tenses).  The authors are also encouraged to remain consistent with their usage of abbreviations.  Readers would benefit from additional explanation of some concepts introduced in the paper (see specific comments).  Authors should consider providing a more detailed explanation of the treatment systems discussed (NTSs, conventional systems, etc.), as these methods can encompass many different technologies/treatment methods.  The nature and process(es) of “community participation” in wastewater treatment must also be defined/clarified.  Many other concepts are introduced with insufficient explanation (see specific section comments) – while this is a review and covers a lot of valuable information, if readers are not presented with context/explanation of this information, they will likely miss the authors’ message.  Please see specific comments (attached).

Comments for author File: Comments.pdf

Author Response

Response to Review Comments

 

Abstract

• Line 10: NTSs are “more” appropriate than what alternative  treatment method?

Response: We have deleted “more”

• Line 11-12: Consider using this line as your first sentence of the abstract, or at least incorporating this information into the first sentence (rather than stating that NTSs are the best option, with no reason).

Response: We have made required changes

• Line 15-16: This sentence is

Response: We have made required changes

 

Introduction

• Line 28: Add “to” between “goes” and “waste”

Response: We have added “to”

• Line 31: Be cautious when using the word “more” or “less” to describe something if you are not referencing anything with which to compare the description. Here, you say “more acute” – more than what? Consider re-wording.
• Response: We have made required changes
• Line 45 – 46: This sentence is unclear – be sure to remain consistent with  verb tense.
• Response: We have made required changes
• Line 45 – 46: In the introduction, please add more background information about NTSs. You mention that they can be soil- and aquatic-based, but how do they generally work? What does the treatment train look like?  Are there many different varieties and/or do they all operate on the   same basic treatment principles? Adding information is critical in making sure readers are all on the same page in their understanding of  

Response: Paragraph 2 and 3 of Introduction provides the background of NTS and type of NTSs. We also discuss different technologies.

• Line 50: How does the community need to participate in NTSs? This is unclear – please add additional

Response: We have provided the explanation in the text. The community need to participate in operation and maintenance (O&M) and monitoring

• Line 65 – 74: This paragraph feels a bit out of place. Consider putting it earlier in the introduction, and also adding background information to it (see previous comments on explaining NTSs and the community participation required for them).

Response: We have reworked and placed it earlier in the section

Material and Methods

• Line 75: Should read “Materials” rather than “Material”

 

 Response: We have corrected the mistake

 

• Line 79: Listing 3 stages and subsequently breaking down your process into 2 stages (i and ii) is a bit confusing. Consider restructuring/rewording.

Response: We have now described that there are 2 stages only

• Line 94: The A in “Articles” should not be capitalized

Response: We have capitalised “A”

Wastewater Treatment: Developed vs Developing Countries

• Line 106: I don’t think this is a fair statement – consider researching/citing the proportion of centralized wastewater treatment plants vs. homes utilizing onsite wastewater treatment systems. Given the recent push for advanced OWTS technologies, stating that developed countries primarily use centralized treatment may not be

Response: we have discussed OWST technologies used in developed countries. We mentioned that developed countries use on-site wastewater treatment systems

• Line 116: Providing examples of NTSs like this is helpful and should be added to the introduction. Also, remain consistent with your abbreviations – you oscillate between NTS and NTSs for natural treatment

Response: We have provided examples in the introduction. NTS is used singular noun and NTS in plural noun.

• Line 131: What do you mean by “conventional technology”? There are many different technologies utilized in the world of wastewater treatment - please be more specific here (you could provide a few examples).

Response: By conventional technology we mean activated sludge process.  We have mentioned it in the text

• Line 136: This concept is unclear – does the rainwater introduce health problems because it is contaminated?

Response: We mean that rainwater generates flow of pathogenic wastewater. We have mentioned it in the text.

• Line 138: What technology are you referencing here, and why does it “need” that specificamount of water?

Response: We mean conventional centralise technology. We have mentioned it in the text.

• Line 152: What do you mean by “biological communities”? Are you referring to the microbial communities responsible for facilitating wastewater treatment, or something else? Please be more clear here, since this is the first time you are mentioning this

Response: The members of biological communities including aquatic plants like floating, sub-merged, and rooted macrophytes helps absorbing pollutants. We have mentioned it in the text.

• Line 162-164: This claim could use a bit more justification/explanation. Also please explain what net present value means in terms of cost (how its’s  calculated/etc.).

Response: We have explained NPV

• Line 184-186: Why is this the case?

Response: We have explained in the text why NTS works better for inner city and decentralize system work better for urban fringe and suburban zones.

 This is because city’s wastewater can flow more easily to the inner city centralized treat-ment facility as compared to urban fringe. Decentralised system are more appropriate in urban fringe and suburban zones as it requires more land and space.

• Line 186-188: This is a confusing claim after previously saying that extreme climate conditions do not compromise the effectiveness of

Response: We have deleted the statements and shifted the discussion in the first paragraph of 3.1

• Line 205: Define O&M.

Response: We have described O&M.

Post-construction safeguards like performance bond, long term post-supervision contract and budget coverage are required to assist the local government in operating and main-taining the system to avoid risk for human and the system

• Line 221: How is the community involved? Again, consider being providing additional detail about community participation efforts in the introduction, that way readers know what  you meanhere.

Response: The community is involved in cleanup of rivers and lakes in exchange of benefits out of selling fish. Thus, community engagement developed a sense of ownership which is one of the important factors of long-term success

We have mentioned it in the text.

• Line 226: What do you mean by saying the filth/odors are being replaced? Are they somehow being eliminated? Or are you suggesting that the benefits of farming/tourism outweigh the cons associated with the filth/odors?

Response: The filth of sewerage coupled with odor and mosquito menace is being reduced and transformed into water resource for farmers and place for tourism.

We mentioned it in the text.

Institutional Issues

• Line 249: What do you consider to be the “process of  community participation”?

Response: The process of community participation involving several steps or activities such as building institutional commitment and partnership for planning, understanding existing context and defining priorities, developing systems and implementation is required for the community to understand their own problem and trigger actions as illustrated by Kar and Chambers (2008) and Parkinson et. al (2014) for implementation of community-led total sanitation.

We mentioned it in the text.

• Line 271: You  list “coproduction” and in this section – be sure to remainconsistent

Response: We have only kept “co-production”

• Line 277: Define NGO

Response: NGO is Non-governmental organization. We mentioned in the text.

• Line 283: What do you mean by your statement of how costs may be passed on to the poor? This suggestion is unclear and needs to be explained more

Response: Understanding the complexity of the O&M of the system and bearing the cost may become an unwanted burden for the poor if they are not consulted before entrusting the responsi-bility of O&M on them.

• Line 298: Define what you mean by “microcredits”

Response: We explained “Microcredit is small loan taken from own saving group (also known as self-help group) or loans disbursed by venture capitalists known as microcredit organisations.”

• Line 314: Briefly describe the Contingent Valuation Method

Response: We explained “ CVM is a survey-based elicitation method to estimate the WTP of goods or services not traded in market. A hypothetical market scenario is formulated and described to the sur-vey respondents to elicit their WTP for the good or service. This process of eliciting WTP is called stated preference method”

• Line 333: Eliminate the word “but”

Response: We deleted “but”.

• Line 338: Replace “has” with “have”

 

Response: We replaced “has” with  “have”

 

 

 

• Line 343: This sentence is unclear

Response: We have rewritten the sentence.

• Figure 2: The flow path of this figure is a little confusing – please indicate where the  process starts

Response: We have replaced the old diagram with new one. The flow paths are now clearer.

• Line 352: What do you mean by “losers”? Consider using a different  word here

Response: People with negative NPV are the losers. We explained this in the text.

• Line 355: Define Palcreto Criteria of distributional analysis (or at least refer readers to  Figure 2)

Response: We had already described Pareto criteria.  Now we have referred to figure 2.

• Line 371: The community may participate in what? This sentence is  

Response: Community participation in O&M in of NTS. We have mentioned it in the text

• Line 380: Replace “are” with “is” (referring to information, singular)

Response: We have replaced “are” with “is”

Summary and Conclusions

• Line 405: Again, developed countries do not solely rely on centralized  treatment

Response: We have mentioned “Centralised system is more appropriate in developed countries as compared to developing countries”

• Line 414: Listening “community” in your list of examples of “community participation”  is redundant

– consider providing a more specific example in lieu of this  word.

Response: We have replaced “community” with “beneficiary” and have rewritten the sentence.

• Consider elaborating a bit more on the social implications of NTS here  as yousummarize/conclude

Response: We have elaborated social implications of NTS in the last paragraph of the article.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The paper looks great!  Readers will definitely benefit from the additional detail/discussion you provided.