Speciation Analysis and Pollution Assessment of Heavy Metals in Farmland Soil of a Typical Mining Area: A Case Study of Dachang Tin Polymetallic Ore, Guangxi
Round 1
Reviewer 1 Report
Dear Authors,
The biblioraphic background could be expanded at the beguinning of the article (e.g. studies developed to improve soils through clays - XU Yi et al. 2017 - Pedosphere 27/2-). Regarding the methodology, statistical correlations and equations seem to me correct and the proposed solutions are feasible.
Regarding being a type of very sand or sandy loam soils, it would be possible, in the future, to delve into other regions of China contaminated by heavy elements with other characteristics of de solil mantle (texture, pH, organic matter with processes that can be produced by OXI-REDOX an environmental conditions), being able to develop other alternatives for the optimization of croplands.
Thank you.
Author Response
We would like to thank all the reviewers for helpful comments. We have addressed all the comments and questions by the reviewer. The red font is the modified part.
Thank you very much for your comments. We have corrected the grammatical errors and format of the paper and modified it according to the suggestions of the other two reviewers.
Reviewer 2 Report
The reviewed manuscript is dealing with the speciation analysis and pollution assessment of heavy metals in farmland soil of typical mining area: A case study of Dachang Tin Polymetallic Ore, Guangxi. Metal contents were measured by ICP-MS, and Tessier's seven-step extraction was used for speciation analysis. Various pollution indices Pi, PN, and RI were used to assess the degree of pollution and ecological risk. In addition, the migration coefficient and bioavailability coefficient are calculated. The manuscript is well presented. I think that the topic is interesting, the study has been conducted solidly in terms of the methodology used. For these reasons, I consider that this manuscript deserves publication after the implication of some minor revisions, the suggestions of which I will provide below:
1. Lines 43; “water areas” change to water bodies.
2. Lines 60:68; Please provide more examples for different ores.
3. Figure 1; Please improve the quality of this figure.
4. Line 107; “5 samples” change to 5 subsamples.
5. Lines 108 and 109; “comprehensive” change to composite.
6. Line 116; remove 1.
7. Lines 118:120; Please add some details about the used procedure.
8. Line 168; The analysis of results is descriptive, needs to be more critics and analytic, and supported by more literature.
9. Lines 173:175; Please revise this sentence, organic matter shows some correlations with the measured heavy metals (see Lines 268:271).
10. Line 197; Please support your discussion with examples dealing with soil contamination (please see; https://doi.org/10.3390/land11030319).
11. Figure 2; Please adjust the figure caption.
12. Lines 219:226; Please move this part to the Materials and Methods section.
Author Response
We would like to thank all the reviewers for helpful comments. We have addressed all the comments and questions by the reviewer. The red font is the modified part.
Response to reviewer 2 comments
- Lines 43; “water areas” change to water bodies.
“water areas” change to water bodies.
- Lines 60:68; Please provide more examples for different ores.
The current geochemical study of ore samples from the Tri-State district and of stream-sediment samples collected from selected sites from the lower Arkansas River drainage basin (the Neosho River, Tar Creek, and Spring River) showed that the effect of past mining activity and leaded gasoline on Pb concentrations in the river sediment can be readily documented. Taylor et al. investigated the relationship between soil Cd, Cu, Pb and Zn contaminants and the location and activities of the Pb-Zn-Ag and Cu mines at Mount Isa, Queensland, Australia. Spatial analysis showed that surface soil metal concentrations are significantly higher within 2 km of XMIM compared to more distant samples, and that more than 1000 property lots are at risk of having detrimentally high soil Pb levels.
- Figure 1; Please improve the quality of this figure.
improve the quality of this figure.
- Line 107; “5 samples” change to 5 subsamples.
“5 samples” change to 5 subsamples.
- Lines 108 and 109; “comprehensive” change to composite.
“comprehensive” change to composite.
- Line 116; remove 1.
remove 1
- Lines 118:120; Please add some details about the used procedure.
Add the extraction sequence and the extraction solution used:
For the analysis of the form of elements in soil, the sequence extraction scheme commonly used at present divides the elements into seven forms, namely, extracting the water-soluble form with water as the extraction agent; Magnesium chloride is used as extractant to extract ion exchange form. The carbonate combined form is extracted with acetic acid-sodium acetate as extractant. Sodium pyrophosphate is used to extract the weak organic combined form (humic acid combined form). Hydroxylamine hydrochloride is used as extractant to extract the iron-manganese oxide combined form. Hydrogen peroxide is used as extractant to extract strong organic combined form. Residual for is extracted by hydrofluoric acid.
- Line 168; The analysis of results is descriptive, needs to be more critics and analytic, and supported by more literature.
The results show that the mining and smelting of non-ferrous metals can obviously lead to the accumulation of some heavy metals (e.g., Cd, Zn, Pb).
- Lines 173:175; Please revise this sentence, organic matter shows some correlations with the measured heavy metals (see Lines 268:271).
The range of organic matter content is 0.5-10.5g/kg, with an average of 4.3g/kg, which indicates that the content of organic matter in soil is small and has impact on the activity of heavy metals.
- Line 197; Please support your discussion with examples dealing with soil contamination (please see; https://doi.org/10.3390/land11030319).
Add the corresponding references:
Li, X.D.; Liu, P.S.; Poon, C.S. Heavy metal contamination of urban soils and street dusts in Hong Kong. Appl. Geochem. 2001,16,1361-1368.
Saleh, A.; Dawood, Y.H.; Gad, A. Assessment of Potentially Toxic Elements Contamination in the Soil of Greater Cairo, Egypt Using Geochemical and Magnetic Attributes. Land 2022,11,319.
- Figure 2; Please adjust the figure caption.
adjust the figure caption.
- Lines 219:226; Please move this part to the Materials and Methods section.
Move the part to the Materials and Methods section.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
The authors presented an interesting study on the speciation analysis and pollution assessment of heavy metals in farmland soil of a typical mining area in China.
The manuscript presents good English level, but there some small mistakes and some unclear phrases in the text (see attached document). Please correct them.
The study was properly organized and described, with some possible improvements. In the attached document you have my remarks and suggestions for improving the manuscript. For these reasons, I recommend the publication of this manuscript only after minor revision.
Comments for author File: Comments.pdf
Author Response
We would like to thank all the reviewers for helpful comments. We have addressed all the comments and questions by the reviewer. The red font is the modified part.
1.What is a natural village?
Natural village is a village formed naturally by villagers after a long time of settlement.
Administrative village is a village-level administrative unit administered by a county government. The natural village belongs to the administrative village.
2.what do you mean by each square?
The sample points are laid out in a grid, with each square representing 1 km2.
3.Why did you use the heavy metals values from the 1990s?
Data from the 1990s are more representative of the region.
4.Please, better define in text the 7 forms and how did you determine the fractions for each heavy metal?
Refer to the technical standards of geological Survey of China Geological Survey (DD2005-03). For the analysis of the form of elements in soil, the sequence extraction scheme commonly used at present divides the elements into seven forms, namely, extracting the water-soluble form with water as the extraction agent; Magnesium chloride is used as extractant to extract ion exchange form. The carbonate combined form is extracted with acetic acid-sodium acetate as extractant. Sodium pyrophosphate is used to extract the weak organic combined form (humic acid combined form). Hydroxylamine hydrochloride is used as extractant to extract the iron-manganese oxide combined form. Hydrogen peroxide is used as extractant to extract strong organic combined form. Residual for is extracted by hydrofluoric acid.
Author Response File: Author Response.pdf
