Inverse geochemical modeling of groundwater salinization in Azraq Basin, Jordan
- PDF / 18,607,619 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 57 Downloads / 216 Views
ORIGINAL PAPER
Inverse geochemical modeling of groundwater salinization in Azraq Basin, Jordan Khalil M. Ibrahim 1 & Ali R. El-Naqa 2 Received: 2 April 2017 / Accepted: 18 April 2018 / Published online: 22 May 2018 # Saudi Society for Geosciences 2018
Abstract The aim is to define the mechanism of chemical reactions that are responsible for the salinization of the Azraq basin along groundwater flow path, using inverse modeling technique by PHREEQC Interactive 2.8 for Windows. The chemical analysis of representative groundwater samples was used to predict the causes of salinization of groundwater. In addition, the saturation indices analysis was used to characterize the geochemical processes that led to the dissolution of mineral constituents within the groundwater aquifer system. According to the modeling results, it was noted that the groundwater at the recharge area was undersaturated with respect to calcite, dolomite, gypsum, anhydrite, and halite. Thus, the water dissolved these minerals during water rock interaction, and therefore, the concentration of Ca, Mg, Na, and SO4 increased along the groundwater flow path. Furthermore, the groundwater at the discharge area was oversaturated with respect to calcite and dolomite. This meant that the water would precipitate these minerals along the flow path, while the water was undersaturated with respect to gypsum and halite throughout the simulated path; this showed the dissolution processes that take place during water-rock interaction. Therefore, the salinity of the groundwater increased significantly along the groundwater flow paths. Keywords Hydrogeochemical modeling . Water-rock interaction . Inverse modeling . Mass balance . Azraq Basin
Introduction The quality of freshwater and/or groundwater at any point on the flow path reflects the combined effects of several geochemical processes along the groundwater flow paths. The anthropogenic activities on all spatial scales affect both water quality and quantity. Among the other factors that influence groundwater quality are geology, climate, vegetation, and residence time (Adjl and Widyastuti 2005). According to Appelo and Postma (1993), geological factors play an essential role in changing the distribution of chemical composition along the groundwater flow path from recharge areas to discharge
* Khalil M. Ibrahim [email protected] Ali R. El-Naqa [email protected] 1
Department of Earth and Environment Sciences, Hashemite University, P.O. Box 150459, Zarqa 13115, Jordan
2
Faculty of Natural Resources and Environment, Hashemite University, P.O. Box 150459, Zarqa 13115, Jordan
zones. Mineral dissolution–precipitation, cation exchange, and redox reaction are fundamental hydrogeochemical processes that modify the chemical composition along the flow path (Gómez et al. 2006; Zhu 2009). For the purpose of accounting changes of chemical composition along the groundwater flow path, hydrogeochemical modeling is commonly used. It helps to interpret geochemical reaction and to determine the existing geochemical reactions al
Data Loading...
