Optimising Brewery-Wastewater-Supported Acid Mine Drainage Treatment vis-à-vis Response Surface Methodology and Artificial Neural Network

Round 1

Reviewer 1 Report

An interesting and useful approach.

Line 52: decimals should be avoided here (COD t)

§1- assuming brewery ww’s COD is mostly in dissolved form they might be in easily degradable form. IF that is the case, it is worth mentioning.

§2 why not make a table introducing the water quality of the sample? I see it is partially included in §2.2 but it should be included at the beginning.

Fig 2: suggest to write the full words in the legend BW/L. Figures should be easy to understand (at least to a certain degree) even without the text.

Figure 3 a-c: good if you can describe the different colours in markers

Author Response

Good day,

Please tubulated responses to both reviewers,

Best regards

SKO Ntwampe

obo All authors

Author Response File: Author Response.docx

Reviewer 2 Report

After reading the manuscript I have following remarks.

1. What is the physical meaning of pH 6.99? Did the Authors measure pH with an accuracy of ±0.01? Check all manuscript body, please.
2. The BW value is specified with high accuracy i.e. ±0.01 mg/L! It should be corrected in all manuscript body. The measured values must be correlated with the calculated values.
3. The characteristics of the brewing and melting wastewater should be accurately described. Quote the relevant literature data in the Introduction part, please.
4. The above remark applies to AMDs characteristics.
5. The application of RSM and ANN in environmental research should be characterized more broadly. Refer to following papers, please. E.g.

Taguchi Method and Response Surface Methodology in the Treatment of Highly Contaminated Tannery Wastewater Using Commercial Potassium Ferrate

Effect of Green Oxidizing Agent on Inhibition of Escherichia coli Present in Livestock Wastes

Treatment of Real Textile Wastewater by Using Potassium Ferrate(VI) and Fe(III)/H2O2. Application of Aliivibrio Fischeri and Brachionus plicatilis Tests for Toxicity Assessment

6. What is the novelty of this work? It should be precisely described.
7. In the section Materials I recommend to start with Chemicals section. After that Bacterial inoculums etc. In the subsection Chemicals all reagents used should be described.
8. In the line 99 Authors claimed that “The characteristics of the AMD is as described in 99 Akinpelu et al [16]” Did the Authors use the same? What does this statement mean?
9. What was the purity of the gases and other reagents used?
10. The parameters (solvents, flow velocity, kind of detectors) for the determination of carbohydrates and other ingredients by using HPLC should be given. It should be completed. It should be in the additional section Analytical Methods.
11. What method was used to determine of sulphate?
12. Why were the values of the independent parameters presented in Table 1 assumed? It should be explained.
13. In the line 140: the described methods (COD etc.) should be in the additional subsection Analytical Methods described. Unfortunately, it is still unknown what methods were used.
14. How are the coefficients in Equation 7 calculated? It should be explained. The Authors should add a table with the coefficients and the calculated errors.
15. In my opinion B^2 is not significant because p-value>0.05. It should be deeply explained based on literature data. Quote relevant references, pleas.
16. What are the limit values for COD and sulfates in South Africa and Nigeria? The results should be discussed based on these data (limit values). It would be interesting for the scientists from other countries. Complete the discussion part, please.

Author Response

Good day,

Please tubulated responses to both reviewers,

Best regards

SKO Ntwampe

obo All authors

Author Response File: Author Response.docx