Abstract
This study shows that the role of various geochemical processes regulating groundwater chemistry can be effectively evaluated using a simple mass balance approach. The application of this approach was successful in a case study on a predominantly agricultural area (Namwon, Korea). For this study, a total of 279 groundwater samples were collected from 93 wells distributed over the study area and analyzed for pH, alkalinity, major cations (Ca2+, Mg2+, Na+, K+), major anions (NO3 -, Cl-, SO4 2-), and silica. Nitrate, chloride, and sulfate concentrations point to the influence of anthropogenic activities on the groundwater composition. Increasing concentrations of major anions and cations toward the top of the aquifer suggests that they come mostly from surface sources. Mass balance analysis based on reaction stoichiometry reveals that the water chemistry is regulated primarily by the combination of three processes: (1) the weathering of minerals such as silicates, carbonates, and/or lime; (2) the input of Cl/SO4 salts; and (3) the generation of nitrates (through nitrification and/or aerobic decomposition of organic matter). Based on this mass balance analysis, we could also quantify the contributions of each process to the observed water chemistry. The results show that mineral weathering is the predominant process affecting groundwater chemistry. Groundwaters more influenced by anthropogenic activities generally show the larger effect of mineral weathering, suggesting that (1) the weathering of silicates might be triggered by protons generated from nitrate generation and/or (2) the water chemistry is affected by lime (CaO) applied to cultivated land and/or carbonates (i.e., CaCO3) in cement materials. However, the influence of protons, which can be co-produced with nitrate, on concentrations of major cations and alkalinity due to ion exchange were revealed to be negligible because the studied groundwater has sufficient alkalinity to neutralize those acids.
| Original language | English |
|---|---|
| Pages (from-to) | 357-369 |
| Number of pages | 13 |
| Journal | Geochemical Journal |
| Volume | 39 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2005 Aug 8 |
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Keywords
- Mass balance
- Mineral weathering
- Namwon
- Nitrate generation
- Proton exchange
- Salts
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics
Cite this
Evaluation of geochemical processes affecting groundwater chemistry based on mass balance approach : A case study in Namwon, Korea. / Kim, Kangjoo; Rajmohan, Natarajan; Kim, Hyun Jung; Kim, Seok Hwi; Hwang, Gab Soo; Yun, Seong Taek; Gu, Baohua; Cho, Min Joe; Lee, Sang Ho.
In: Geochemical Journal, Vol. 39, No. 4, 08.08.2005, p. 357-369.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evaluation of geochemical processes affecting groundwater chemistry based on mass balance approach
T2 - A case study in Namwon, Korea
AU - Kim, Kangjoo
AU - Rajmohan, Natarajan
AU - Kim, Hyun Jung
AU - Kim, Seok Hwi
AU - Hwang, Gab Soo
AU - Yun, Seong Taek
AU - Gu, Baohua
AU - Cho, Min Joe
AU - Lee, Sang Ho
PY - 2005/8/8
Y1 - 2005/8/8
N2 - This study shows that the role of various geochemical processes regulating groundwater chemistry can be effectively evaluated using a simple mass balance approach. The application of this approach was successful in a case study on a predominantly agricultural area (Namwon, Korea). For this study, a total of 279 groundwater samples were collected from 93 wells distributed over the study area and analyzed for pH, alkalinity, major cations (Ca2+, Mg2+, Na+, K+), major anions (NO3 -, Cl-, SO4 2-), and silica. Nitrate, chloride, and sulfate concentrations point to the influence of anthropogenic activities on the groundwater composition. Increasing concentrations of major anions and cations toward the top of the aquifer suggests that they come mostly from surface sources. Mass balance analysis based on reaction stoichiometry reveals that the water chemistry is regulated primarily by the combination of three processes: (1) the weathering of minerals such as silicates, carbonates, and/or lime; (2) the input of Cl/SO4 salts; and (3) the generation of nitrates (through nitrification and/or aerobic decomposition of organic matter). Based on this mass balance analysis, we could also quantify the contributions of each process to the observed water chemistry. The results show that mineral weathering is the predominant process affecting groundwater chemistry. Groundwaters more influenced by anthropogenic activities generally show the larger effect of mineral weathering, suggesting that (1) the weathering of silicates might be triggered by protons generated from nitrate generation and/or (2) the water chemistry is affected by lime (CaO) applied to cultivated land and/or carbonates (i.e., CaCO3) in cement materials. However, the influence of protons, which can be co-produced with nitrate, on concentrations of major cations and alkalinity due to ion exchange were revealed to be negligible because the studied groundwater has sufficient alkalinity to neutralize those acids.
AB - This study shows that the role of various geochemical processes regulating groundwater chemistry can be effectively evaluated using a simple mass balance approach. The application of this approach was successful in a case study on a predominantly agricultural area (Namwon, Korea). For this study, a total of 279 groundwater samples were collected from 93 wells distributed over the study area and analyzed for pH, alkalinity, major cations (Ca2+, Mg2+, Na+, K+), major anions (NO3 -, Cl-, SO4 2-), and silica. Nitrate, chloride, and sulfate concentrations point to the influence of anthropogenic activities on the groundwater composition. Increasing concentrations of major anions and cations toward the top of the aquifer suggests that they come mostly from surface sources. Mass balance analysis based on reaction stoichiometry reveals that the water chemistry is regulated primarily by the combination of three processes: (1) the weathering of minerals such as silicates, carbonates, and/or lime; (2) the input of Cl/SO4 salts; and (3) the generation of nitrates (through nitrification and/or aerobic decomposition of organic matter). Based on this mass balance analysis, we could also quantify the contributions of each process to the observed water chemistry. The results show that mineral weathering is the predominant process affecting groundwater chemistry. Groundwaters more influenced by anthropogenic activities generally show the larger effect of mineral weathering, suggesting that (1) the weathering of silicates might be triggered by protons generated from nitrate generation and/or (2) the water chemistry is affected by lime (CaO) applied to cultivated land and/or carbonates (i.e., CaCO3) in cement materials. However, the influence of protons, which can be co-produced with nitrate, on concentrations of major cations and alkalinity due to ion exchange were revealed to be negligible because the studied groundwater has sufficient alkalinity to neutralize those acids.
KW - Mass balance
KW - Mineral weathering
KW - Namwon
KW - Nitrate generation
KW - Proton exchange
KW - Salts
UR - http://www.scopus.com/inward/record.url?scp=22944457508&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=22944457508&partnerID=8YFLogxK
U2 - 10.2343/geochemj.39.357
DO - 10.2343/geochemj.39.357
M3 - Article
VL - 39
SP - 357
EP - 369
JO - Geochemical Journal
JF - Geochemical Journal
SN - 0016-7002
IS - 4
ER -