Recycling Nutrient-Rich Municipal Wastes into Ready-to-Use Potting Soil: An Approach for the Sustainable Resource Circularity with Inorganic Porous Materials

Round 1

Reviewer 1 Report

1. Please state the objective of the study in abstract

2. Method should be revised for reproducibility

3. Result and discussion must be improved by explaining why phenomenon occurred (see reviewed manuscript)

Author Response

Thank you very much for your comments and suggestions about our submitted manuscript. Your suggestions helped us greatly in improving the imperfect points. We checked and revised the manuscript point to point according to your suggestions. We believe that the manuscript becomes much better than the first version. The following is the answers to the questions (red font). All the revised sites in the manuscript were also highlighted using the yellow font.

 

Reviewer #1

1. Please state the objective of the study in abstract

Objective of the study was added in the abstract as follow;

The main purpose of the present work was to investigate the feasibility of pumice (PU) and expanded perlite (EP) on composting parameters, nutrient bioavailability and suitability of SS to serve as an ornamental substrate.

 

2. Method should be revised for reproducibility

Method sections were carefully checked and especially Total Kjeldahl N and statistical analyzes were explained.

3. Result and discussion must be improved by explaining why phenomenon occurred (see reviewed manuscript)

The results and discussion section was improved in terms of detailed phenomena, especially in section 3.4.  Thank You.

Reviewer 2 Report

The paper addresses an important topic related to the use of waste products as an alternative to conventional non-renewable peat and nutrient-rich renewable materials. However, the authors need to improve the presentation of the results.

My main comments are:

1) LACK OF STATISTICAL ANALYSIS! The authors write in methodology L134-138 about the statistical analysis performed, but unfortunately no figure presents the results. The reader is not able to determine whether the results presented are statistically significantly different. Why are there no correlations? No PCA, PCoA?

2) Figures - are incomplete, missing captions, explanations of legends, are inaccurate (cut up) - more details below. It looks as if the authors wanted to put as much information as possible on one figure, and this is neither readable nor good looking. It might be worth considering additional figures or tables (they might be easier to read).

Detailed comments:

[1] L20-23: in my opinion such detailed results are not needed in the abstract

[2] L48-49: references?

[3] L57-58: references?

[4] L76: since the authors refer to "few studies" the references should be given

[5] L77-80: it would be good to have a research hypothesis of some kind

[6] L93-106: it would be good to add a diagram showing the layout of the experiment, this would be more readable and attractive to the reader.

[7] L113: explain the abbreviation OM

[8] L115: specify which dorma of nitrogen was being determined (total, mineral?)

[9] L116: why cress? Since the paper cites the ornamental plant industry as an example?

[10] Figure 1: figures 1a, 1b, 1c, 1d should be listed; besides, the graphs on the left steon have only 17 days on the axis and those on the right have 19 days. If it is a matter of lack of space, the figures should be inserted separately. The symbols in the legend should be explained below the figure. The graphs show the dynamics, the changes, but we do not see whether these differences are statistically significant. Perhaps the results should be presented in a different way? Or introduce a label at least for statistically significantly different values? The graphs on the right end at 19 days, while according to the description (L101) the experiment lasted 3 weeks, i.e. 21 days. All graphs should therefore show results for this (21 day) period.

[11] Figure 2: same comment as above; the x-axis should show the same number of days and they should all be signed. Because the reader does not know what is between 1 and 10 days, where only one value is given. Where is the statistical analysis?

[12] Figure 4: also figures 4a-i should be listed; no units, no Y and X axis captions, no explanation of the legend, no statistical analysis... - should be completed.

[13] There are errors in the writing of references in the text.

[14] The discussion could be more elaborated.

[15] Conclusions are not supported by statistical analysis.

Author Response

Response to Reviewers

Thank you very much for your comments and suggestions about our submitted manuscript. Your suggestions helped us greatly in improving the imperfect points. We checked and revised the manuscript point to point according to your suggestions. We believe that the manuscript becomes much better than the first version. The following is the answers to the questions (red font). All the revised sites in the manuscript were also highlighted using the yellow font.

Reviewer #2

The paper addresses an important topic related to the use of waste products as an alternative to conventional non-renewable peat and nutrient-rich renewable materials. However, the authors need to improve the presentation of the results. Thank You.

My main comments are:

• LACK OF STATISTICAL ANALYSIS! The authors write in methodology L134-138 about the statistical analysis performed, but unfortunately no figure presents the results. The reader is not able to determine whether the results presented are statistically significantly different. Why are there no correlations? No PCA, PCoA?

Analysis table and explanations showing the relationships between composting and all effect parameters in detail have been added as a new section (3.5).

3.5. Correlation of investigated parameters

A correlation matrix of the composting parameters showed the positive and negative relationship between the inorganic BA incorporation and the physicochemical characteristics of composting treatments (Figure 5). The increasing rate of inorganic BA incorporation to SS correlated positively with the stability parameters GI, composting parameters temperature rise and CO₂, and nutrient parameter TKN, which was interpreted as the complete decomposition of phytotoxic compounds and preserved valuable primary nutrient, nitrogen, in the compost. Accordingly, a higher rate of BA incorporation had a negative correlation with parameters such as the pH, OM, and nutrient parameters phosphorus and potassium contents due to the dilution effect of in higher dose of BA incorporation.

	BA-rate	TKN	pH	OM	MC	TEMP	CO2	CH4	H2S	TP	TK	GI
BA-rate	1
TKN	0.93**	1									-1         0         1
pH	-0.67**	-0.65**	1
OM	-0.82**	-0.87**	0.61**	1
MC	-0.54**	-0.56**	0.19	0.27	1
TEMP	0.40*	0.45*	-0.53**	-0.37*	-0.36*	1
CO2	0.42*	0.22	-0.35	-0.10	-0.33	0.40*	1
CH4	0.09	-0.14	0.01	0.09	0.17	-0.16	0.28	1
H2S	-0.13	-0.37*	0.12	0.35	0.45*	-0.31	0.40*	0.52**	1
TP	-0.89**	-0.83**	0.66**	0.85**	0.15	-0.30	-0.23	-0.13	0.01	1
TK	-0.49**	-0.44*	0.13	0.63**	-0.24	-0.04	-0.02	-0.21	-0.14	0.72**	1
GI	0.61**	0.56**	-0.81**	-0.43*	-0.21	0.24	0.26	0.09	-0.01	-0.57**	-0.07	1

 

 

 

Figure 5. Correlation heatmap from composting parameters, nutrient characteristics, and stability with increasing incorporation rate of inorganic porous BA incorporation to SS. Correlation value ranges between 0 to ±0.35 specified weak, ±0.36 to ±0.47 indicated moderated, and ±0.48 to ±1.0 represented strong positive/ negative correlation. *P < 0.05; **P < 0.01.

 

Since most of the strong positive and negative correlation was related to the BA incorporation rate, the SS was suggested as a suitable condition created by inorganic porous pumice and expanded perlite for the decomposition of organic matter. The moisture-related parameters associated with H₂S and CH₄ generation and CO₂ evolution demonstrated the positive contribution of BA to microbial activity and temperature increase. The correlations of stability parameter GI were strongly positive with BA rate and total Kjeldahl nitrogen TKN and strongly negative with pH, which also related to the pH balancing capacity of BA.

• Figures - are incomplete, missing captions, explanations of legends, are inaccurate (cut up) - more details below. It looks as if the authors wanted to put as much information as possible on one figure, and this is neither readable nor good looking. It might be worth considering additional figures or tables (they might be easier to read).

Figures were carefully checked and simplified for better readability. Thank you.

Detailed comments:

[1] L20-23: in my opinion such detailed results are not needed in the abstract. Deleted.

[2] L48-49: references? Added.

[3] L57-58: references? Added.

[4] L76: since the authors refer to "few studies" the references should be given Done.

[5] L77-80: it would be good to have a research hypothesis of some kind

Corrected please kindly check the last sentences of Introduction as yellow background.

[6] L93-106: it would be good to add a diagram showing the layout of the experiment, this would be more readable and attractive to the reader.

[7] L113: explain the abbreviation OM

Corrected as first organic matter (OM) term in Abstract.

[8] L115: specify which dorma of nitrogen was being determined (total, mineral?)

Corrected as Total Kjeldahl Nitrogen (TKN) which measure ammoniacal and organic nitrogen.

[9] L116: why cress? Since the paper cites the ornamental plant industry as an example?

The seed germination index (GI) is a commonly used indicator of compost maturity and is a required index in many national standards. Seeds of different plant species vary markedly in sensitivity to the biological toxicity of compost. Cress seed is widely used to evaluate the compost maturity with the GI in most published studies and original procedure proposed by Zucconi 1982, due to the its rapid germination and sensitivity to the toxic compounds. 

 [10] Figure 1: figures 1a, 1b, 1c, 1d should be listed; besides, the graphs on the left steon have only 17 days on the axis and those on the right have 19 days. If it is a matter of lack of space, the figures should be inserted separately. The symbols in the legend should be explained below the figure. The graphs show the dynamics, the changes, but we do not see whether these differences are statistically significant. Perhaps the results should be presented in a different way? Or introduce a label at least for statistically significantly different values? The graphs on the right end at 19 days, while according to the description (L101) the experiment lasted 3 weeks, i.e. 21 days. All graphs should therefore show results for this (21 day) period.

Now, all the figures have been corrected as all graphs show 21 days’ period.

[11] Figure 2: same comment as above; the x-axis should show the same number of days and they should all be signed. Because the reader does not know what is between 1 and 10 days, where only one value is given. Where is the statistical analysis? Done.

[12] Figure 4: also figures 4a-i should be listed; no units, no Y and X axis captions, no explanation of the legend, no statistical analysis... - should be completed.

In this Figure, we used a bi-directional bar chart (Mirror bar chart) to present our results for easy comparison that comparatively displays two sets of data side by side along a vertical axis. Y-axis is displayed in the middle of the chart. The left side indicates the total concentration of individual plant nutrients, and the right side shows the available concentration of the nutrient.

[13] There are errors in the writing of references in the text. Corrected.

[14] The discussion could be more elaborated.

Authors thank the Reviewer for providing us valuable suggestions for improvement of the manuscript. Following the suggestion of the Reviewer, we have addressed the comment in the Discussion section of the revised manuscriptbeing submitted now.

[15] Conclusions are not supported by statistical analysis. Done

Author Response File: Author Response.docx