Potential for Natural Attenuation of Domestic and Agricultural Pollution in Karst Groundwater Environments
, Mina Bizic 3,*,†, Danny Ionescu 3,*,†, Cecilia Maria Chiriac 4,5, Marius Kenesz 1,2, Carmen Roba 6, Artur Ionescu 6, Alexandru Fekete 7, Ionut Cornel Mirea 2,8 and Oana Teodora Moldovan 1,2
Round 1
Reviewer 1 Report
The research is very interesting, it is known that anthropogenic activities and septic tanks negatively affect the quality of groundwater. Since such a large number of species of microorganisms was examined, it would be clearer (Figures 4 and 5) if they were grouped into two groups: the first group of microorganisms that are pathogenic and harmful to health and to see their numbers upstream and downstream, the second group would be those contributing microorganisms reduce the concentration of organic pollutants for which abundance upstream and downstream should also be shown. Show both of these groups in a time series to see the trend throughout the year.
It would be interesting to make a correlation analysis of the obtained results.
In the part of instrumental analysis, supplement with data on the detector used in ion chromatography, as well as on the operating conditions of the detector in the analysis of cations and anions in water.
Author Response
Please see the attachment. Thank you.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article submitted for review raises an extremely important issue of water quality, which is often used as a source of drinking water.
A careful analysis was made contaminants with anthropogenic origin ultimately reach the subsurface, with detrimental effects on the fragile groundwater ecosystem and the downstream springs, which are often used as drinking water sources by the local human communitie.
What, the authors did is very important, as it shows what water quality problems not only Romania but most Central and Eastern European countries are struggling. In my opinion, the work is very rich.
The authors took samples from five sites in four seasons and performed a physicochemical and microbiological analysis.
- However, I believe that tables S1, S2, S3 should be an integral part of the article. I know they are extensive, but it is they that show the enormous amount of work. Please think about how you can turn them on;
- or just describe how many tests it was without referring to tables S1, S2, S3.
The concentration of organic matter, considered here as an indicator of pollution, was significantly lower in the downstream springs than in the upstream, pre-karst, waters. The microbial community composition varied largely between upstream and downstream locations. This suggests that the HKS can filter out part of the polluting organic matters and, with it, part of the associated microorganisms.
- However, please re-examine the taxonomic record (also in the figures).
The work is well edited but:
- In Figure 1, I would place parts from a to c, not b, a, c.
The authors included the literature review in the discussion in a very interesting way. In my opinion, this is a very good formula.
Author Response
Please see the attachment. Thank you.
Author Response File: Author Response.pdf
Reviewer 3 Report
This paper analyzed the concentration of most chemical compounds and the microbial community composition from upstream to downstream in five hydrokarst systems. Generally, the paper is well organized. However, some details are not well described. My major comments are as follows.
- The significance of the study is not clear. How to use the results?
- The title of the paper is “Natural Attenuation of Domestic and Agricultural Pollution in Karst Groundwater Environments”. But there is no analysis of pollution sources. It is suggested that the title be changed to “characteristic analysis of the water chemistry and the microbial community composition in five hydrokarst systems “
- Please reorganize the abstract. The variation characteristics of main chemical compounds in the study area should be quantified, and the study results should be analyzed in detail.
- The introduction does not provide sufficient background and include all relevant references. Please add the current research status in this topic in the part of introduction.
- Please reorganize the part of conclusions.
Author Response
Please see the attachment. Thank you.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The manuscript is revised according to reviewer's comments and it is suggested that it be accepted in present form.
