Hydrogeochemical Behavior of Shallow Groundwater around Hancheng Mining Area, Guanzhong Basin, China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The present study reports the hydrochemical characteristics for the groundwater in a mining area of northern China. Generally, the paper is well organized. The findings are interesting and could provide insights for local water practice. I would like to recommend the paper to be published after some necessary revisions. An improvement in English language is also suggested. Please find the detailed comments below.

In the abstract, please indicate the timescale of the sampling and analyses. Annual, seasonal or single time? Additionally, you mentioned that hydrogen and oxygen isotopes were used for the water source identification. However, I cannot find such part in the main text.

Lines 13-16: What methods are these findings based on?

Lines 34-55: Please include the statements of importance in understanding the interactions between hydrochemical ions and the water source in environmental assessments. The application of hydrochemical and isotopic methodologies should be emphasized.The following paper may be helpful and could be referred to:https://doi.org/10.1016/j.marpolbul.2022.113532; https://doi.org/10.3390/su151411034

In the introduction, it is suggested to describe the environmental backgrond under coal mining and underline the urgent need to investigate the hydrochemical evolution in the study area.

Fig 1: it is suggested to plot the distribution of rivers and sampling points in a DEM map, to better understand the flow directions and recharge relations.

In the M & M section, please describe when you conducted the sampling, and how many times you sampled for each point.

Table1: The EC values were measured according to the statements in "Materials and methods" section, so why wasn't the parameter shown in this Table?

Fig. 2-4: Please correctly use superscripts and subscrpts for the ions.

The format should be improved following the journal guidelines.

For the reference list, please check and improve it. For example, note "(in Chinese)" for the cited papers in Chinese  (e.g., No.18 & 39); use uniformed format for the note of volume, issue and DOI.

 

Comments on the Quality of English Language

English is suggested to be checked and improved.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I found the manuscript “Hydrogeochemical behavior of shallow groundwater around  Hancheng mining area, Guanzhong Basin, China,” submitted by Kou et al., interesting. The Authors considered the analysis of hydrochemical data from 18 samples of shallow groundwater around the Hancheng mining area in Guanzhong Basin. Gibbs diagram and Piper diagram were used to study the hydrogeochemical behavior of shallow groundwater around the Hang-cheng mining area.   Hydrogen and oxygen isotope data show that groundwater in the study area is recharged by local recent precipitation.  The main ion chemistry of shallow groundwater in the studied area is controlled by rock weathering, and pyrite oxidation is an important factor affecting SO4 concentration. The conclusions imply that:

(1)    The main cation components in groundwater in the study area were Mg2+, Ca2+ , Na+, and K+ , and the anion components were HCO3 -, Cl-, and SO4

(2)    The chemical components of groundwater in the study area are mainly affected by rock weathering, and there is cation exchange. Na++Cl- comes from the dissolution of halogen, Ca+ comes from the dissolution of gypsum, and SO4 2- concentration is affected by  pyrite oxidation.

Cl- and SO4 2- are not only controlled by natural factors but also affected by human input.

 

I think the paper should better describe similar cases, including eventual remediation techniques, in short sentences. 

Comments on the Quality of English Language

See Comments for Authors

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The paper has been revised carefully. I agree it to be published in WATER.