Achieving High-Efficiency Wastewater Treatment with Sequencing Batch Reactor Grundfos Technology

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study demonstrates the innovative performance of the SBR-GT (Sequencing Batch Reactor – GRUNDFOS Technology) system for wastewater treatment, while emphasizing the need for further SBR optimization, particularly for large-scale applications, complex wastewater, and emerging contaminants. This manuscript presents a novel design of a sequencing Batch Reactor which showed high treatment efficiency of domestic wastewater. Several comments showld be addressed before giving the final recommendations: 

1- The authors used abbreviation for many names. However, they they still repeat the full name and the abbreviation in the manuscript. After using the abbreviation and the full nam for the first time, then only the abbreviation is needed. 

2- The measurements of COD and BOD5 in long term treatment experiments is questionable. As the .       organic compounds are being degraded COD decreases and may be BOD5. Some of the organic material which is now are not calculated in the BOD5 because they are not now the microorganism can not degrade it. However, after a time and some changes in their structure and they become non-toxic or easy to biodegrade by the cells, and consequently BOD5 increases. For this reason, I advise to measure the Total Organic Carbon TOC as a more stable variable than COD and BOD5. Fig. 2 shows the Violin plot for reduction of TSS, TN TP and COD and BOD. It is clear that the range of COD reduction is much wider than that of COD5.

3-   A  schematic diagram of the whole processes is needed. 

4- A suitable graphical abstract in missed. It is advisable to add a graphical abstract that reflects the methodology, analysis and results.

5- The organization of the manuscript should be revised. The discussion of any figure or table must be after the figure or the table. Their discussion should be after them.

6-The main results found in the discussion can be summarized and compared with previous published results of domestic wastewater treatment processes. 

7- Some recommendations for future work can be added after the conclusions.

8- The figures found in Appendix 1 and 2 are poor and not clear. More clear photos and more illustration are needed.

9- The selected composition of the industrial wastewater used in addition to the domestic wastewater must be identified. 
10- The parts of Figure 1 should be named as a, b, and c and the same for the corresponding illustration.

 

 

Author Response

Comments 1:

This study demonstrates the innovative performance of the SBR-GT (Sequencing Batch Reactor – GRUNDFOS Technology) system for wastewater treatment, while emphasizing the need for further SBR optimization, particularly for large-scale applications, complex wastewater, and emerging contaminants. This manuscript presents a novel design of a sequencing Batch Reactor which showed high treatment efficiency of domestic wastewater. Several comments showld be addressed before giving the final recommendations: 

1- The authors used abbreviation for many names. However, they they still repeat the full name and the abbreviation in the manuscript. After using the abbreviation and the full nam for the first time, then only the abbreviation is needed. 

Response 1:

Thank you for highlighting this. We have revised the manuscript to ensure that after introducing the full name and abbreviation for the first time, only the abbreviation is used in subsequent mention

Comments 2

2- The measurements of COD and BOD5 in long term treatment experiments is questionable. As the organic compounds are being degraded COD decreases and may be BOD5. Some of the organic material which is now are not calculated in the BOD5 because they are not now the microorganism can not degrade it. However, after a time and some changes in their structure and they become non-toxic or easy to biodegrade by the cells, and consequently BOD5 increases. For this reason, I advise to measure the Total Organic Carbon TOC as a more stable variable than COD and BOD5.

Fig. 2 shows the Violin plot for reduction of TSS, TN TP and COD and BOD. It is clear that the range of COD reduction is much wider than that of COD5.

Response 2:

We acknowledge the reviewer's concern about the reliability of COD and BOD5 in long-term treatment experiments. We could not measure Total Organic Carbon (TOC) due to the unavailability of the required technology and equipment, we have included this as a recommendation for future work.

Comments 3

3-   A  schematic diagram of the whole processes is needed. 

Response 3:

A schematic diagram of the entire process has been added to enhance clarity and provide a comprehensive understanding of the methodology.

Comments 4 and 5

4- A suitable graphical abstract in missed. It is advisable to add a graphical abstract that reflects the methodology, analysis and results.

5- The organization of the manuscript should be revised. The discussion of any figure or table must be after the figure or the table. Their discussion should be after them.

Response 4 and 5:

A suitable graphical abstract summarizing the methodology, analysis, and results has been added to the manuscript. The organization has been revised so that the discussion of each figure or table directly follows it for better readability and logical flow. If we know correctly, according to MDPI rules, citations should appear before the table or figures if possible. Additionally, the discussion should precede the table or figures whenever possible.

Comments 6 and 7:

6-The main results found in the discussion can be summarized and compared with previous published results of domestic wastewater treatment processes. 

7- Some recommendations for future work can be added after the conclusions.

Response 6 and 7:

We have summarized the main findings in the discussion section and compared them with relevant published results on domestic wastewater treatment processes. Please check the lines [462-478]:

"Sequencing Batch Reactor and Advanced Sequencing Batch Reactor (ASBR) were assessed for operational efficiency. This technology achieved an average 92% removal of BOD, COD, and TSS, confirming they met acceptable regulatory standards [50]. COD reduction provides an incomplete and inconsistent measure of wastewater treatment effectiveness due to the variability of compositions over short periods. Effective assessment should emphasize more stable indicators, particularly total organic carbon, to accurately evaluate the efficiency of new technologies and wastewater treatment processes [51]. Enhancing Sequencing Batch Reactor performance extends beyond dissolved oxygen (DO) control and requires advanced modeling to effectively treat municipal wastewater. Integrated hybrid control strategies—such as Proportional Integral, Fractional Proportional Integral, and fuzzy logic—alongside real-time monitoring of critical parameters and the calculation of the Effluent Quality Index are essential [52]. Effluents from a vegetable processing plant for canned soup were analyzed to assess the impact of Solid Retention Times of 15 and 25 days, showing that optimal time enhances organic matter and nutrient removal. Understanding the biodegradable COD fraction is crucial for optimizing the system, as nitrogen and phosphorus removal relies on biomass assimilation and a healthy microbial population [53].

Recommendations for future work, particularly focusing on SBR optimization for large-scale applications and handling complex wastewater, have been added at the end of the conclusions.

 

Comments 8, 9 and 10:

8- The figures found in Appendix 1 and 2 are poor and not clear. More clear photos and more illustration are needed.

9- The selected composition of the industrial wastewater used in addition to the domestic wastewater must be identified. 
10- The parts of Figure 1 should be named as a, b, and c and the same for the corresponding illustration.

Response 8, 9 and 10:

The figures in Appendix 1 and 2 have been excluded. The composition of the industrial wastewater used, in addition to domestic wastewater, has been clearly identified and described in the methodology section. The parts of Figure 1 have been labeled as a, b, and c, and corresponding illustrations have been updated accordingly.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors 

please find the reviewer comments in the attached document. 

Comments for author File: Comments.pdf

Comments on the Quality of English Language

i have provided my comments in the authors comments box. 

Author Response

Reviewer comments 1

Manuscript ID: processes-3506452 Manuscript title: Achieving High-Efficiency Wastewater Treatment with Sequencing Batch Reactor (SBR) GRUNDFOS Technology (GT) The manuscript titled "Achieving High-Efficiency Wastewater Treatment with Sequencing BatchReactor (SBR) GRUNDFOS Technology (GT)" presents an interesting research idea. The authors have put considerable effort into producing a valuable research piece. However, the manuscript's quality has been compromised by several careless and repetitive mistakes. To enhance the overall standard of the manuscript, the authors are advised to carefully revise the content in accordance with the following comments.

 

Response 1:

We have addressed the points raised and incorporated them into the study wherever possible.

 

 

Comments 2 and 3

1. The manuscript is poorly drafted. The language is poor and has many formatting issues. The same mistakes have been repeated again and again. The authors need a substantial revision to make it publishable in this journal.

2. Use the terms Sequencing Batch Reactor (SBR) and The SBR-GT (Sequencing Batch Reactor–GRUNDFOS Technology) consistently.

 

Response 2 and 3:

Thank you for your valuable comments, which have significantly enhanced the depth and clarity of our work. We now consistently use the terms "Sequencing Batch Reactor Grundfos Technology (SBR-GT)" throughout the manuscript for clarity and uniformity.

 

Comments 3-7

3. Line 45 to 46 change the sentence for clarity

4. Introduce MBR on its first appearance and do the same for the rest of manuscript

5. Line 70 to 71 the term is already introduced then no need to write the full name again here. Same is the case for line 89

6. Methodology part is not very well written the authors are advised to rewrite with proper citations 7. The same mistake has been continuously and carelessly repeated Table 2. Parametrs for wastewater treatment with Sequencing Batch Reactor (SBR) GRUNDFOS Technology (GT).

 

Response 3-7:

Thank you for pointing this out. We have thoroughly revised the manuscript to improve its language and formatting. Repeated mistakes have been corrected to ensure consistency and quality.

The sentence has been rephrased for clarity and improved readability. We have introduced the abbreviation "MBR" clearly upon its first appearance and ensured that subsequent mentions are consistent across the manuscript. Repeated full-term names have been replaced with abbreviations where appropriate to improve the flow of the text. The methodology section has been rewritten with proper citations to enhance clarity and alignment with academic standards. Please check. All methodology provided is mark in yellow. Repeated mistakes in Table 2 have been corrected, and we have ensured accuracy and consistency throughout the paper.

 

Comments 8

8. Please mention and cite figures from the appendixes

 

Response 8:

All figures from the appendices have been excluded.

 

Comments 9 and 10

9. The discussion part need to be discussed in the light of literature published on similar subjects

10. The quality of the figures need to be improved not to just put an image.

 

Response 9 and 10:

The discussion has been updated and expanded by incorporating insights from relevant literature to provide a robust analysis of the findings. We added this literature list in the Discussion section in lines [462-478]:

"Sequencing Batch Reactor and Advanced Sequencing Batch Reactor (ASBR) were assessed for operational efficiency. This technology achieved an average 92% removal of BOD, COD, and TSS, confirming they met acceptable regulatory standards [50]. COD reduction provides an incomplete and inconsistent measure of wastewater treatment effectiveness due to the variability of compositions over short periods. Effective assessment should emphasize more stable indicators, particularly total organic carbon, to accurately evaluate the efficiency of new technologies and wastewater treatment processes [51]. Enhancing Sequencing Batch Reactor performance extends beyond dissolved oxygen (DO) control and requires advanced modeling to effectively treat municipal wastewater. Integrated hybrid control strategies—such as Proportional Integral, Fractional Proportional Integral, and fuzzy logic—alongside real-time monitoring of critical parameters and the calculation of the Effluent Quality Index are essential [52]. Effluents from a vegetable processing plant for canned soup were analyzed to assess the impact of Solid Retention Times of 15 and 25 days, showing that optimal time enhances organic matter and nutrient removal. Understanding the biodegradable COD fraction is crucial for optimizing the system, as nitrogen and phosphorus removal relies on biomass assimilation and a healthy microbial population [53].

The figures have been excluded for mthe manuscript.

 

 

Comments 11:

11. Some recent studies are suggested to be cited https://doi.org/10.1002/asia.202300618

 

Response 11:

The suggested study has been cited, along with other relevant recent studies, to strengthen the manuscript.

 

Comments 12 and 13:

12. Section 2.2, the content needed to be supported with proper citations. Include more recent studies

13. Check the entire manuscript for grammatical mistakes, spell mistakes and reference style as per the journal requirements and guidelines.

 

Response 12 and 13:

Section 2.2 has been revised to include appropriate citations and references to recent studies to substantiate the content. We have performed a meticulous revision of grammar, spelling, and reference formatting to ensure compliance with the journal's guidelines.

Reviewer 3 Report

Comments and Suggestions for Authors

1)The work problem is unclear

2)New work should be introduced in the introduction 

3)A comparative study is mandatory

4)What are the strong points of this process compared to other water treatment processes?

5)Other analyses such as TA, TAC and hardness (HT) should also be added.

Comments on the Quality of English Language

corrections to minor methodological errors and text editing

Author Response

Comments 1:

1) The work problem is unclear

Response 1:

We have addressed the points raised and incorporated them into the study wherever possible in the Introdcution chapter (lines 115-121]:

"This study highlights the innovative performance of a new wastewater treatment system tailored for small-scale applications, tackling complex challenges in municipal areas with emerging contaminants. The objectives of the study were: a) Assessing the usability of the Sequencing Batch Reactor Grundfos Technology; b) Evaluating reductions in oxygen indicators (COD, BOD), total nitrogen, total phosphates, and total suspended solids concentrations; c) Modeling flow patterns within the chamber of the newly developed wastewater treatment tank".

Comments 2, 3 and 4:

2) New work should be introduced in the introduction 

3)A comparative study is mandatory

4) What are the strong points of this process compared to other water treatment processes?

Response 2, 3 and 4:

Thank you for your valuable comments, which have significantly enhanced the depth and clarity of our work. We have added a schematic diagram of the entire SBR-GT process to highlight the strengths of this approach, particularly in terms of the waste treatment process. These paragraph has been added:

"The wastewater from the buffer tank is pumped into the SBR reaction chamber in a manner that does not disturb the sediment layer accumulated at the bottom of the chamber after sedimentation. The incoming wastewater raises the liquid level, causing the treated wastewater to overflow into the static decanter, from where it is discharged to the receiving environment (Figure 2A). The mixing of raw wastewater with concentrated sludge promotes intensive anaerobic and anoxic processes, ensuring effective biological defosfitation and denitrification processes, while also improving the sedimentation capabilities of the sludge (anaerobic selector). After filling the SBR reactor with a new batch of sewage, the reaction phase begins. Alternating mixing and aeration of the entire tank contents effectively reduces the contaminants in the sewage to the required level. The aeration process is controlled to optimize electricity consumption. In the final period of the reaction phase, it is possible to add chemicals to adjust pH and precipitate phosphorus (Figure 2B). Upon the completion of the treatment process, the aeration and mixing systems are halted, and the sedimentation process begins. During the final period of sedimentation, the submersible pump removes part of the thickened sludge from the bottom of the chamber as excess sludge. Once the sedimentation process is finished, the system enters a new cycle by simultaneously filling with a new batch of raw sewage and removing a batch of treated sewage (Figure 2C)."

We added comparative study in the Discussion section in lines [462-478]:

"Sequencing Batch Reactor and Advanced Sequencing Batch Reactor (ASBR) were assessed for operational efficiency. This technology achieved an average 92% removal of BOD, COD, and TSS, confirming they met acceptable regulatory standards [50]. COD reduction provides an incomplete and inconsistent measure of wastewater treatment effectiveness due to the variability of compositions over short periods. Effective assessment should emphasize more stable indicators, particularly total organic carbon, to accurately evaluate the efficiency of new technologies and wastewater treatment processes [51]. Enhancing Sequencing Batch Reactor performance extends beyond dissolved oxygen (DO) control and requires advanced modeling to effectively treat municipal wastewater. Integrated hybrid control strategies—such as Proportional Integral, Fractional Proportional Integral, and fuzzy logic—alongside real-time monitoring of critical parameters and the calculation of the Effluent Quality Index are essential [52]. Effluents from a vegetable processing plant for canned soup were analyzed to assess the impact of Solid Retention Times of 15 and 25 days, showing that optimal time enhances organic matter and nutrient removal. Understanding the biodegradable COD fraction is crucial for optimizing the system, as nitrogen and phosphorus removal relies on biomass assimilation and a healthy microbial population [53]."

Comments 5:

5) Other analyses such as TA, TAC and hardness (HT) should also be added

 

Response 5:

Unfortunately, we could not include analyses such as TA, TAC, and hardness (HT) due to the unavailability of the required technology and equipment at our disposal. However, we’ve provided detailed alternative analyses that complement the study for future recommendation

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I have provided my comments to the editor. 

Author Response

Reviewer comments 1

Manuscript ID: processes-3506452 Manuscript title: Achieving High-Efficiency Wastewater Treatment with Sequencing Batch Reactor (SBR) GRUNDFOS Technology (GT) The manuscript titled "Achieving High-Efficiency Wastewater Treatment with Sequencing BatchReactor (SBR) GRUNDFOS Technology (GT)" presents an interesting research idea. The authors have put considerable effort into producing a valuable research piece. However, the manuscript's quality has been compromised by several careless and repetitive mistakes. To enhance the overall standard of the manuscript, the authors are advised to carefully revise the content in accordance with the following comments.

 

Response 1:

We have addressed the points raised and incorporated them into the study wherever possible.

 

Comments 2 and 3

1. The manuscript is poorly drafted. The language is poor and has many formatting issues. The same mistakes have been repeated again and again. The authors need a substantial revision to make it publishable in this journal.

2. Use the terms Sequencing Batch Reactor (SBR) and The SBR-GT (Sequencing Batch Reactor–GRUNDFOS Technology) consistently.

 

Response 2 and 3:

Thank you for your insightful comments, which have greatly improved the depth and clarity of our work. We have now ensured consistent usage of the term "Sequencing Batch Reactor Grundfos Technology (SBR-GT)" throughout the manuscript for clarity and uniformity. In certain sections, such as lines 130 and 134 or 137, we have opted to use the abbreviation (SBR-GT).

 

Comments 3-7

3. Line 45 to 46 change the sentence for clarity

4. Introduce MBR on its first appearance and do the same for the rest of manuscript

5. Line 70 to 71 the term is already introduced then no need to write the full name again here. Same is the case for line 89

6. Methodology part is not very well written the authors are advised to rewrite with proper citations

7. The same mistake has been continuously and carelessly repeated Table 2. Parametrs for wastewater treatment with Sequencing Batch Reactor (SBR) GRUNDFOS Technology (GT).

 

Response 3-7:

Thank you for pointing this out. We have thoroughly revised the manuscript to improve its language and formatting. Repeated mistakes have been corrected to ensure consistency and quality.

The sentence has been rephrased for clarity and improved readability in lines 47-51.

We have introduced the abbreviation "MBR" clearly upon its first appearance and ensured that subsequent mentions are consistent across the manuscript in line 46.

Repeated full-term names have been replaced with abbreviations where appropriate to improve the flow of the text. The methodology section has been rewritten with proper citations to enhance clarity and alignment with academic standards. Please check.

All methodology provided is mark in yellow in lines 165-183.

Repeated mistakes in Table 2 have been corrected, and we have ensured accuracy and consistency throughout the paper.

 

 

Comments 8

8. Please mention and cite figures from the appendixes

 

Response 8:

All figures from the appendices have been excluded.

 

Comments 9 and 10

9. The discussion part need to be discussed in the light of literature published on similar subjects

10. The quality of the figures need to be improved not to just put an image.

 

 

Response 9 and 10:

The discussion has been revised and expanded by incorporating relevant literature insights to provide a robust analysis of the findings. This includes an exploration of SBR processes and multi-phase CFD simulations.For example, lines 366–371 state: "During the first aeration phase of the SBR, multi-phase CFD simulations identified a reduced stagnation zone in the center of the bioreactor due to high air flow rates (average 4,500 m³/h) compared to inflow rates (250 m³/h). Air distribution was significantly influenced by circular and vertical flows driven by mixers, with reduced air volume observed in areas lacking diffusers and the center of the tank during the anaerobic phase [37]."

The figures have been excluded from the manuscript.

 

 

Comments 11:

11. Some recent studies are suggested to be cited https://doi.org/10.1002/asia.202300618

 

Response 11:

The suggested study has been cited, along with other relevant recent studies, to strengthen the manuscript in lines 77-81.

 

 

Comments 12 and 13:

12. Section 2.2, the content needed to be supported with proper citations. Include more recent studies

13. Check the entire manuscript for grammatical mistakes, spell mistakes and reference style as per the journal requirements and guidelines.

 

Response 12 and 13:

In the discussion, section "4.2" has been revised to include appropriate citations and references to recent studies, ensuring the content is well-substantiated. Please check lines 452–469: "COD reduction provides an incomplete and inconsistent measure of wastewater treatment effectiveness due to the variability of compositions over short periods. Effective assessment should emphasize more stable indicators, particularly total organic carbon, to accurately evaluate the efficiency of new technologies and wastewater treatment processes [50]. Enhancing Sequencing Batch Reactor performance extends beyond dissolved oxygen (DO) control and requires advanced modeling to effectively treat municipal wastewater. Integrated hybrid control strategies—such as Proportional Integral, Fractional Proportional Integral, and fuzzy logic—alongside real-time monitoring of critical parameters and the calculation of the Effluent Quality Index are essential [51]. Effluents from a vegetable processing plant for canned soup were analyzed to assess the impact of Solid Retention Times of 15 and 25 days, showing that optimal time enhances organic matter and nutrient removal. Understanding the biodegradable COD fraction is crucial for optimizing the system, as nitrogen and phosphorus removal relies on biomass assimilation and a healthy microbial population [52]. Similar to our SBR-GT technology, Continuous-flow Sequencing Batch Reactors improve wastewater treatment by allowing continuous flow during operation. This design reduces downtime, enhances efficiency, and minimizes the reactor's footprint, making it ideal for various applications [50]".

 

We have revised grammar, spelling, and reference formatting to ensure full compliance with the journal's guidelines.