Hydrogeochemistry of groundwater from karstic limestone aquifer highlighting arsenic contamination: case study from Jordan

Abstract

Groundwater wells in the Amman-Wadi Es Sir Aquifer (B2/A7) throughout Jordan are investigated for their arsenic (As) and element-by-element geochemical behavior. Groundwater wells are found to have total arsenic concentrations above the recommended levels designated by the Jordanian drinking water standard, the Environmental Protection Agency of the United States, and the World Health Organization. Arsenic distribution in the aquifer is variable, but it is detected with a concentration of ≥10 ppb in 87 samples out of the analyzed 150 groundwater samples, with a maximum concentration of 173 ppb. Elevated As concentrations can be attributed to several mechanisms. One of these mechanisms is accounted for to the interaction between groundwater and the natural phosphorite deposits in the upper part of the aquifer and oil shale deposits overlying it. The high significant correlation between arsenic, phosphorus, and calcium concentrations in the analyzed groundwater samples suggest that these elements are derived from the same source.Moreover, scanning electron microscopy shows the association of As with the P and Ca in the phosphorite; pyrite is present in the oil shale samples, which were collected from the Muwaqqar formation overlying the aquifer. EDAX analysis shows that substantial As concentrations are present in phosphate and pyrite. This study suggests that the major mechanism responsible for releasing As from the aquifer material into the groundwater is a simple dissolution reaction. However, Piper and Durov diagrams, correlation coefficients, and factor analysis all suggest that water interaction with phosphate and oil shale deposits, sorption of heavy metals, and simple dissolution of iron oxyhydroxides are together the primary factors affecting the chemistry of the groundwater and responsible for the elevated As values in some wells.

Threads of memory: Reviving the ornament of a dead child at the Neolithic village of Ba`ja (Jordan)

“…Red calcite can result from calcite precipitation within sedimentary rocks rich with iron. This phenomenon is documented for the Transdanubian Range in Hungary [ 118 ] and can be envisaged for the Greater Petra Area when taking into account that this region is part of the Amman-Wadi Es Sir formation (B2/A7), which is a karstic system of silicified limestone [ 119 ], fig. 1.…”

Evaluating Water-Yield Property of Karst Aquifer Based On The AHP And CV

“…The energy input of soluble rock, water, and CO 2 system is realized by the continuous infiltration of groundwater. The material output of this system, namely, the discharge of CaCO 3 , must also depend on the runoff and discharge of water (Guo et al 2019;Bicalho et al 2012;Al et al 2015). Therefore, the circulation alternation of groundwater is necessary and enough condition to ensure karst development.…”

A Vision on a UNESCO Global Geopark at the Southeastern Dead Sea in Jordan—Geosites and Conceptual Approach

“…Its main tributary is the Jordan river, but also numerous ephemeral streams, wadis, aquifers, and submarine springs provide inflow to the lake [23]. The main groundwater bearing formations in the proposed Geopark area are the shallow alluvial aquifer of the Lisan formation of Tertiary and Quaternary origin, the mostly karstified limestone of the Amman-Wadi Es Sir aquifer of the Belqa and Ajlun groups of the Upper Cretaceous, the limestone/marl formations of the Ajlun group, the Kurnub sandstone aquifer of the Lower Cretaceous and parts of the Zarqa group of Triassic-Jurassic age as well as parts of the Ram (Disi) fossil groundwater aquifer of Cambrian origin [24,25]. The Dead Sea serves hereby as the main "sink" in the hydrogeologic system of the region, having tributaries that range more than 100 km inland [26].…”

“…Land 2022, 11, x FOR PEER REVIEW 4 of of the Amman-Wadi Es Sir aquifer of the Belqa and Ajlun groups of the Upper Cretaceou the limestone/marl formations of the Ajlun group, the Kurnub sandstone aquifer of th Lower Cretaceous and parts of the Zarqa group of Triassic-Jurassic age as well as parts o the Ram (Disi) fossil groundwater aquifer of Cambrian origin [24,25]. The Dead Sea serve hereby as the main "sink" in the hydrogeologic system of the region, having tributarie that range more than 100 km inland [26].…”