Treatment of Winery Wastewater with a Combination of Adsorption and Thermocatalytic Processes

Round 1

Reviewer 1 Report

The manuscript concerns an interesting issue which is the treatment of winery wastewater with the use of adsorption and thermocatalytic oxidation processes. The authors studied three processes: adsorption with activated sodium bentonite; thermocatalytic oxidation with potassium persulfate and sodium percarbonate; and combined treatment adsorption-thermocatalytic oxidation processes. Moreover, the authors evaluated the effect of the treatment processes in the germination index of different plant seeds.

The manuscript is written neatly and clearly. The title reflects the article’s content. The objectives of the study are clearly defined. The results are presented in a comprehensible way. The tables and figures present essential data.

However, the manuscript requires a few corrections:

• Line 70: The formula of sodium percarbonate is incorrect. It should be Na₂CO₃·1.5H₂O₂ instead of Na₂CO₃·1.5H₂O.
• In the 2.4 section “Activated sodium bentonite characterization” the authors described the results of the FTIR analysis for activated sodium bentonite but did not include the spectrum. Please provide FTIR spectrum of activated sodium bentonite.
• Line 165 ad 166: in my opinion, the results of FTIR analysis are not properly described. At 902 cm^-1 there are the stretching vibration of structural Al–O–Al–OH groups (not Al–Al–OH), and at 883 cm^-1 there are the stretching vibration of structural Al–O–Fe–OH groups (not Al–Fe–OH).
• Line 363: The designation of the oxidation potential for the sulfate radical is incorrect. Instead of the sulfate radical, there is a sulfate ion.
• Equation 10 is incorrect (it should be H₂O₂ instead of H₂O). Please correct this equation.

Overall, the article shows interesting results but needs to be improved before publication.

Author Response

Dear Reviewer,

Thank you very much for the comments. Allow to improve the quality of the final article. It has been revised as suggested and the changes are shaded in yellow in the manuscript.

Yours sincerely,

Authors

Comments and Suggestions for Authors

The manuscript concerns an interesting issue which is the treatment of winery wastewater with the use of adsorption and thermocatalytic oxidation processes. The authors studied three processes: adsorption with activated sodium bentonite; thermocatalytic oxidation with potassium persulfate and sodium percarbonate; and combined treatment adsorption-thermocatalytic oxidation processes. Moreover, the authors evaluated the effect of the treatment processes in the germination index of different plant seeds.

The manuscript is written neatly and clearly. The title reflects the article’s content. The objectives of the study are clearly defined. The results are presented in a comprehensible way. The tables and figures present essential data.

However, the manuscript requires a few corrections:

• Line 70: The formula of sodium percarbonate is incorrect. It should be Na₂CO₃·1.5H₂O₂ instead of Na₂CO₃·1.5H₂O.

Reviewer 1, thank you for your comment, the formula was corrected.

• In the 2.4 section “Activated sodium bentonite characterization” the authors described the results of the FTIR analysis for activated sodium bentonite but did not include the spectrum. Please provide FTIR spectrum of activated sodium bentonite.

Reviewer 1, thank you for your observation. Indeed, the FTIR chart should be present in the text, and therefore, the FTIR spectrum was provided. It appears as “Figure 1”.

• Line 165 ad 166: in my opinion, the results of FTIR analysis are not properly described. At 902 cm^-1 there are the stretching vibration of structural Al–O–Al–OH groups (not Al–Al–OH), and at 883 cm^-1 there are the stretching vibration of structural Al–O–Fe–OH groups (not Al–Fe–OH).

Thank you for your commentary. The changes in the structural groups were corrected.

• Line 363: The designation of the oxidation potential for the sulfate radical is incorrect. Instead of the sulfate radical, there is a sulfate ion.

Thank you, the sentence was corrected.

• Equation 10 is incorrect (it should be H₂O₂ instead of H₂O). Please correct this equation.

Thank you, the chemical composition of Equation 10 was corrected.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper reports treatment of winery wastewater by combination of adsorption and thermocatalytic processes. The removal rate of TOC, COD, and total polyphenols were 76.7, 81.4 and 99%, respectively. The effect of treatment processes in the germination index of plant seeds indicates low phytotoxicity effect. Overall, authors presented an interesting topic and could be considered for publication on Processes. However, several issues need to be addressed before publication:

1. Some parameters in Table 2 have no clear definition or explanation. Such as: , . A1/ A2 – absorbance at 520 nm, does it mean both A1 and A2 are absorbance at 520. TP and PP are calculated by the same equation. How can one get two different parameters (TP and PP) from the same equation please explain.
2. In the SPC releasing mechanism section, how is the experiment carried out? It seems SPC was applied to water instead of wastewater. If it is true, how come there is TOC in water? As for 1g/L of SPC, why is the measured H2O2 significantly larger than theoretical value. I think it is beyond the measurement error. Thus, authors must give an explanation.
3. The results in some figures of the thermocatalytic oxidation with KPS and SPC too close to draw a conclusion, such as Figure 4, 5, and 6. It is recommended that authors add y error bars to all the figures.
4. Some typos in manuscripts such as: Page 2 line 70, formula of sodium percarbonate wrong; Page 9 line 274, Thermocatalytic oxidation with KPS nad SPC.

Comments for author File: Comments.pdf

Author Response

Treatment of winery wastewater by combination of adsorption and thermocatalytic processes

Submitted to Processes (processes-1510771)

Dear Reviewer 2,

Thank you very much for the comments, which allows us to improve the quality of the article. It has been revised as suggested and the responses to comments are in blue on this page and shaded in yellow in the manuscript.

Yours sincerely,

Authors

Comments and Suggestions for Authors

This paper reports treatment of winery wastewater by combination of adsorption and thermocatalytic processes. The removal rate of TOC, COD, and total polyphenols were 76.7, 81.4 and 99%, respectively. The effect of treatment processes in the germination index of plant seeds indicates low phytotoxicity effect. Overall, authors presented an interesting topic and could be considered for publication on Processes. However, several issues need to be addressed before publication:

1. Some parameters in Table 2 have no clear definition or explanation. Such as: A1/ A2 – absorbance at 520 nm, does it mean both A1 and A2 are absorbance at 520. TP and PP are calculated by the same equation. How can one get two different parameters (TP and PP) from the same equation please explain.

Reviewer 2, thank you for your commentary. Yes, A1 and A2 are both absorbances at 520 nm. We have modified that information in Table 2.

Regarding TP and PP equations, there was a mistake, but PP equation was changed.

2. In the SPC releasing mechanism section, how is the experiment carried out? It seems SPC was applied to water instead of wastewater. If it is true, how come there is TOC in water? As for 1g/L of SPC, why is the measured H2O2 significantly larger than theoretical value. I think it is beyond the measurement error. Thus, authors must give an explanation.

Thank you for your observations.

In the SPC releasing mechanism section, the SPC was dissolved in water. The objective was to measure the release of H₂O₂ by this compound, in order to understand how much H₂O₂ will be release in the wastewater. The TOC present in water was possibly due to the CO₂ present in the atmosphere. However, we performed a new analysis, and the TOC results were zero. The information in “Table 4” was changed.

Regarding the application of 1 g/L SPC, the value of H₂O₂ measured is not significantly higher than theoretical value or beyond the measurement error. The value detected was within the values from the calibration curve.

3. The results in some figures of the thermocatalytic oxidation with KPS and SPC too close to draw a conclusion, such as Figure 4, 5, and 6. It is recommended that authors add y error bars to all the figures.

Reviewer 2, thank you for your observations. We have performed a one-way ANOVA, and added to the charts error bars and letters to observe significant changes in the results.

4. Some typos in manuscripts such as: Page 2 line 70, formula of sodium percarbonate wrong; Page 9 line 274, Thermocatalytic oxidation with KPS and SPC.

Thank you for your commentaries. The changes in page 2 and page 9 were performed.

Author Response File: Author Response.pdf