The Design and Performance Prediction Model of an Integrated Scheme of a Membrane Bioreactor and Anaerobic Digester for the Treatment of Domestic Wastewater and Biowaste

Round 1

Reviewer 1 Report

Manuscript Number: sustainability-2501033

A design and performance prediction model of an integrated scheme of membrane bioreactor and anaerobic digester for the treatment of domestic wastewater and biowaste.

The present work tries to model the behavior of a compound system for the treatment of wastewater and the subsequent treatment of the waste generated in this process. To do this, he uses real data obtained to carry out the modeling that is compared with the operation of an installation on an experimental scale. Taking into account the acceptable adjustments obtained, they carry out the design of a pilot plant.

GENERAL COMMENTS

In the first place, it is important to value the long period of experimentation that has taken to obtain the results that have given rise to the realization of this work. It seemed to me a very interesting and necessary work to predict the changes that may occur in a real wastewater treatment plant in which the fluctuations of the water to be treated can cause problems. In addition, the proper management of the waste generated to achieve a process whose impact is minimal is a philosophy that must begin to be included in all the investigations to be carried out.

I think the work is interesting and it should be accepted after some minor revisions.

FORMAT COMMENTS

My comments are mainly about format issues. There are serious flaws in this aspect, figures have been found that are not fully displayed, and some quotes that are not in the proper format. In addition, the charges of the analyzed ions must be included.

Author Response

Please see attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

Introduction

Dear Authors, congratulation for the outcome of this very interesting experimental and modelling project. The system is innovative and it is really interesting to read about it and obtain relevant information about its performance. I mainly have one comment which is eventually to introduce the variability dimension in your modelling exercise which will provide additional quality to your overall modelling and simulation work.

 

Major comments:

Figures with observation would benefit from error bars to give a hint on the “observation variability” just as also more information on the confidence intervals of the resulting models based on the inputted variability due to aspect such as “quantification or place of sampling originating from the 3D wise “unideal mixing” of such systems”.

Otherwise, specify that the error bars are “within the dot” or why it is not relevant to focus on that aspect. This comment is mainly because, biological models of such systems look more serious when “variability and probability” of predictions are also plotted. Otherwise, you could provide them in the supplementary material which I couldn´t find in the paper.

Minor comments

14: Membrane aerobic bioprocess. Could be reformulated to immediately bring clarity in the abstract. “Membrane aerobic bioprocess” is an approach not a process and thus in a standalone form at abstract level it does not inform on what the bioprocess step is really doing e.g. is it aerobic composting ? Oxidative biological degradation of organic matter/activated sludges? Just to be precise on the “in and outs” of the process even the information comes later or if some readers might find it trivial.

22: the predominance of the heterotrophic. Consider removing “the” since there is not only 1 or if yes, then specify it.

42: same comment as line 14 or change to aerobic and anerobic bioprocesses are an // or aerobic and anaerobic waste bioprocessing... Again just to bring the highest possible clarity to the subject matter.

46-47: check formulation of “it is deal for small to medium…”

63-64: check formulation: This way, early adopters could be essentially supported à did you state: “these models could bridge the distance between technological innovation and full scale exploitation while “supporting adopters/decision makers”?

80: this fact shed light for the need for less complicated à This reveals/shows the need …..

158: missing reference

213 - 224: figure formatting but also figure 5 line 242,

215: “illustrating” à are illustrating or illustrate

248: “autotrophic bacteria also presented an increase but very limited, underlining the….. revise formulation with e.g. autotrophic bacteria presented a very limited increase which underlines/ underlining that

369 – 370: formulation: In this context, a pilot was constructed, operated under various…. In this context, a pilot was constructed and operated under….

371: formulation à by the pilot plant operation it was demonstrated. Change eventually to e.g. the pilot plant operation demonstrated…

389 to 390. Check the formulation.

Author Response

Please see attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

In the present manuscript, a mathematical model was developed to simulate the performance of the integrated scheme including an aerobic membrane-based process and anaerobic digestion to treat wastewater and biowaste. The study is overall well-designed. My comments are listed below:

1. The introduction lacks background information about the aerobic membrane-based process and anaerobic digestion, why we want to integrate them, and why their integration is innovative.

2. It is not clear how zero waste is achieved. Need more information in the introduction.

3. Membrane pore size of 0.1 pm does not look right.

4. There is an error message in line 158.

5. Check the formatting of all figures and figure captions in the result section.

6. Need to add reference(s) for "By the pilot plant operation it was demonstrated the feasibility of an innovative integrated system that will be able to produce biogas suitable for combustion (used as renewable electric and thermal energy), a stabilized solid fertilizer and high quality water that can be used either within the process or as irrigation water in agriculture." (lines 371-374).

7. Instead of saying the model is satisfactory, please report the model simulation accuracy quantitatively.

There are many typographical, formatting, and grammatical errors. Please double-check!

Author Response

Please see attached file.

Author Response File: Author Response.pdf