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Due to the interaction of water with hot deep bedrock within the geothermal system, the geochemical, elemental and radiological aspects of water and nearby soil and sediment samples are essential to investigate the water quality and the potential ecological impacts on the nearby area. In this study, four geothermal water springs located within Al-L...
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The main sources of radon in the air of dwellings are soil, building materials, and groundwater. This study aimed to determine the exhalation rate of ²²²Rn from samples made of concrete and cement mortars, as well as to evaluate by means of gamma spectrometry the hazard indexes associated with other radionuclides present in the studied samples of b...
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... Soil samples were dried, pulverized into a fine powdery in a ball mill grinder, and homogenized by sieving (2 mm pore size mesh) into double-bagged polyethylene containers (Monged et al., 2018). ...
Crude oil waste management is challenging due to the diverse constituents of the waste and its consequent impact on valued environmental receptors (water and soil). Characterization of the potentially toxic elements (PTEs) in soils and water within the surroundings of crude oil waste management facility is imperative, to aid evaluation of potential risks. The study assessed the potential environmental and human health risks posed by PTEs in soil and water from surroundings and adjoining settlement communities. A total of forty-four (44) samples were analyzed for PTEs (Cr, Pb, Zn, Co, Mn, Ni, Hg, Fe, As, Cu, Hg, and Cd) and physicochemical properties in both matrices. The total carcinogenic risk (TCR) for adults and children in the neighbouring community was 4.73 × 10−6 and 1.2 × 10−4, respectively, which was due to the high carcinogenic slope factor of arsenic. A strong correlation was observed between the PTEs and physicochemical properties, and their health risk was attributed to both geogenic and anthropogenic factors. The study indicated that the human health and ecological risk values obtained were within acceptable limits, with the waste management facility posing a higher risk in comparison to the nearby community. These risks may be attributed to the specific nature and intensity of the activities conducted at the facility. Hence, there is the need for continuous promotion of occupational and public awareness on the health and environmental impact of crude oil waste management.
... Geothermal resources in Saudi Arabia are promising. Several exploration campaigns and research studies have investigated Saudi Arabia's geothermal resources for decades [56][57][58][59][60][61][62], with a couple focusing on the Al-Lith area in southwestern Saudi Arabia [63][64][65][66]. The Al-Lith area has four hot springs with surface temperatures ranging from 41 • C to 96 • C, with Ain Al-Harrah having the highest. ...
The Controlled-Source ElectroMagnetic (CSEM) method provides crucial information about reservoir fluids and their spatial distribution. Carbon dioxide (CO2) storage, enhanced oil recovery (EOR), geothermal exploration, and lithium exploration are ideal applications for the CSEM method. The versatility of CSEM permits its customization to specific reservoir objectives by selecting the appropriate components of a multi-component system. To effectively tailor the CSEM approach, it is essential to determine whether the primary target reservoir is resistive or conductive. This task is relatively straightforward in CO2 monitoring, where the injected fluid is resistive. However, for scenarios involving brine-saturated (water-wet) or oil-wet (carbon capture, utilization, and storage—CCUS) reservoirs, consideration must also be given to conductive reservoir components.
The optimization of data acquisition before the survey involves analyzing target parameters and the sensitivity of multi-component CSEM. This optimization process typically includes on-site noise measurements and 3D anisotropic modeling. Based on our experience, subsequent surveys tend to proceed smoothly, yielding robust measurements that align with scientific objectives. Other critical aspects to be considered are using magnetotelluric (MT) measurements to define the overall
background resistivities and integrating real-time quality assurance during data acquisition with 3D modeling. This integration allows the fine tuning of acquisition parameters such as acquisition time and necessary repeats. As a result, data can be examined in real-time to assess subsurface information content while the acquisition is ongoing. Consequently, high-quality data sets are usually obtained for
subsequent processing and initial interpretation with minimal user intervention. The implementation of sensitivity analysis during the inversion process plays a pivotal role in ensuring that the acquired data accurately respond to the target reservoirs’ expected depth range. To elucidate these concepts, we present an illustrative example from a CO2 storage site in North Dakota, USA, wherein the long-offset
transient electromagnetic method (LOTEM), a variation of the CSEM method, and the MT method were utilized. This example showcases how surface measurements attain appropriately upscaled log-scale sensitivity. Furthermore, the sensitivity of the CSEM and MT methods was examined in other case histories, where the target reservoirs exhibited conductive properties, such as those encountered in enhanced oil recovery (EOR), geothermal, and lithium exploration applications. The same equipment specifications were utilized for CSEM and MT surveys across all case studies.
... Several exploration campaigns and research studies have been carried out to investigate the geothermal resources of Saudi Arabia since decades ago [9][10][11][12][13][14][15][16][17][18][19][20], with a couple of them focusing on Al-Lith's geothermal resources [21][22][23][24][25][26]. One of the conclusions is that Saudi Arabia has considerable promising geothermal resources. ...
A couple of studies show that Saudi Arabia has promising geothermal resources. The most prominent sites are located around Al-Lith, with four hot springs, where Ain Al-Harrah has the highest temperature. Previous studies suggest that this hot spring's geothermal reservoir is promising and may provide the Al-Lith region with long-term electricity. Our key objective is to investigate and explore more comprehensively the prospect of geothermal resources around the Ain Al-Harrah hot spring. To achieve this goal, we acquired broadband magnetotellurics (MT) data in the period range 0.001-60 s for three different sampling frequencies at 15 soundings along one profile. The 2D inversion results show three main units. A conductive anomaly (< 30 Ohm.m) at a depth > 3.5 km below the surface is most likely related to a geothermal heat source. The high resistive zones (roughly 200-4000 Ohm.m) are associated with hard-rock geological formations. Although uncertain, a detected medium resistive body (30-200 Ohm.m) at a depth of 800 m below the surface possibly indicates the pathway of geothermal fluids forming a convection cell between the hot body and the surface. A lateral resistivity discontinuity is considered a fracture zone acting as a pathway for the fluids to reach the surface forming the hot spring.
... These solid samples were air dried, then the dried samples were crunched with a clean mortar and pestle and then sieved using a 0.65-micron sieve (Akanchise et al., 2020). Then, the determination of metal(oid)s for (Ag, As, Cd, Cr, Co, Cu, Fe, Mn, Mo, Pb, Zn, Ni, and Al) was performed by ICP-MS (Azimov et al., 2020;Fitamo et al., 2007;Francioli et al., 2021;Mao et al., 2017;Monged et al., 2018;Xiang et al., 2020). ...
... Scanning electron microscope (FEI Model QUANTA 450) was used for imaging of dry leachate concentrate obtained through rotary evaporation followed by air drying at 25 °C. The solid samples, which represent a mixture of mineral matrix, organic matter, bacteria and other microorganisms (fungi and parasites), were gold coated and examined under the SEM for microbial community morphology and ICP-MS (Azimov et al., 2020;Fitamo et al., 2007;Francioli et al., 2021;Mao et al., 2017;Monged et al., 2018;Xiang et al., 2020). ...
Environmental pollution is a serious issue all around the world, especially when it is caused by metal(oid)s and pathogenic microorganisms. This study reports here for the first time on the contamination of soil and water with metal(oid)s and pathogenic bacteria directly resulting from the Soran Landfill Site. Soran landfill is a level 2 solid waste disposal site that lacks leachate collection infrastructure. The site is potentially an environmental and public hazard caused by metal(oid)s content and significantly dangerous pathogenic microorganisms through leachate release into the soil and nearby river. This study reports on the levels of the metal(oid)s content of As, Cd, Co, Cr, Cu, Mn, Mo, Pb, Zn, and Ni obtained by inductively coupled plasma mass spectrometer in soil, leachate stream mud, and leachate samples. Five pollution indices are used to assess potential environmental risks. According to the indices, Cd and Pb contamination is significant, whereas As, Cu, Mn, Mo, and Zn pollution is moderate. A total of 32 isolates of bacteria were defined from soil, leachate stream mud, and liquid leachate samples: 18, 9, and 5, respectively. Moreover, 16 s rRNA analysis suggested that the isolates belong to three enteric bacterial phyla of Proteobacteria, Actinobacteria, and Firmicutes. The closest GenBank matches of 16S rDNA sequences indicated the presence of the genera: Pseudomonas, Bacillus, Lysinibacillus, Exiguobacterium, Trichococcus, Providencia, Enterococcus, Macrococcus, Serratia, Salinicoccus, Proteus, Rhodococcus, Brevibacterium, Shigella, Micrococcus, Morganella, Corynebacterium, Escherichia, and Acinetobacter. The identity percentage was mostly between 95%–100%. The results of this study show the levels of microbiological and geochemical contamination of soils, surface and potentially ground water with harmful microorganisms and toxic metal(oid)s originating specifically from Soran landfill leachate which subsequently incorporated into the surrounding environment, creating thus a considerable health and environmental risk.
... However, this method is still useful for assessing an element's enrichment/depletion degree relative to a specific source [27]. The application of EF analysis for environmental assessment in geothermal areas has been demonstrated by several authors ( [28], [29], [30], [31]). Shakeri et al. [31] adopted EF classification after Sutherland [32] in their study on elements enrichment in the sediment of a geothermal area. ...
... The radioactivity of groundwaters has been investigated in several research lines. Most of the available publications deal with geological (Sanjuan et al. 2016;Bakhur 2018;Monged et al. 2018;Rama et al. 2019), hydrogeological (Zebracki et al. 2017;Fan et al. 2018;Ogawa et al. 2019), and geochemical (Marsac et al. 2017;Krall et al. 2019;Faraj et al. 2020) controls of natural radionuclide patterns in waters of different compositions (Yu et al. 2019;El-Mezayen et al. 2020). Under different geological settings and hydrogeological conditions over the Earth, the background 222 Rn concentrations vary within a very broad range. ...
The first integrated isotope and chemistry results have been obtained for radon-rich thermal waters from the Belokurikha field which are used at a large spa resort in Altai, Russia. The waters reside in an unconfined aquifer composed of Quaternary soft sediments and in a confined (artesian) aquifer of monolithic to weathered Upper Paleozoic granites. The waters belong to three geochemical groups: low-radon nitrogen-silicic interstitial waters in weathered Paleozoic granites; groundwaters of REE-enriched and background compositions; surface waters of the Belokurikha River. The interstitial waters in granites have HCO3-SO4 Na and SO4-HCO3 Na major-ion chemistry, total salinity from 198 to 257 mg/L, pH = 8.6–9.6, silica contents of 19.8 to 24.6 mg/L, and ²²²Rn activity from 160 to 360 Bq/L (290 Bq/L on average). Judging by their oxygen and hydrogen (deuterium) isotope compositions (−17.5 to −14.2 ‰ and −126.9 to −102.7 ‰, respectively), the Belokurikha aquifers recharge with infiltrating meteoric water, especially the winter precipitation. The carbon isotope composition of dissolved inorganic carbon (−9.7 to −25.6 ‰ δ¹³СDIC) corresponds to biogenic origin. Comparison of radon-rich mineral waters from different areas of southern Siberia shows that the change from oxidized to reduced environments leads to ²³²Th/²³⁸U increase from 4.20∙10⁻⁵–7.39∙10⁻² to 0.0022–26, respectively, with an intermediate range of 2.63∙10⁻⁵–0.20 in transitional conditions.
... Detection limits were equal to three times the sample standard deviation of several measurements of the constituent in a blank solution analyzed as a sample. Relative standard deviation for each analytical method is determined from the measurement of an analyte concentration at least ten times the detection limit (Monged et al. 2018). ...
This work aims to evaluate radioactivity levels of 238U (226 Ra), 232 Th(228 Ra), and 40 K and the associated radiological hazard indices, as well as to assess the current status and concentrations of heavy metals along the coastline of the Gulf of Suez, in order to identify potential sources of contamination and to construct radioactivity baseline for this area. Measurements of the activity concentrations of 238 U(226 Ra), 232 Th(228 Ra), and 40 K in Bq kg −1 of the collected samples were carried out using high-purity germanium (HPGe) detector. Heavy metals in seawater, shore sediment, and algae samples were determined using ICP-OES. The average activity concentrations of 238 U(226 Ra), 232 Th(228 Ra), and 40 K were found to be 13.79 ± 0.75, 14.57 ± 1.15, and 128.9 ± 4.15 Bq kg −1 , respectively. The radiological hazard indices of absorbed dose rate in nGy h −1 (D), annual effective dose rate in mSv y −1 , AED, radium equivalent activity in Bq (Ra eq), external and internal hazard indices (H ex , H in), and cancer risk factor were calculated and compared with the worldwide averages. The distribution patterns of annual effective dose (AED) at the Suez Gulf showed that the south east of the Gulf is characterized by higher AED. Water quality parameters (water temperature, salinity, pH, DO, and Eh) reveal that Suez Gulf was undoubtedly affected by the rate of the human activities. Heavy metal concentrations in shore sediments showed some variation within the study area and followed the following order: Fe > Mn > Zn > Al > B > Co > Ni > Pb > V > Cr > Mo > Cu > Cd. Furthermore, heavy metal concentrations indicated that northern part of the Gulf contains the highest levels of these metals compared to the southern one.
This work aims to investigate and explore the prospect of geothermal resources around the Ain Al-Harrah hot spring in the Al-Lith area, which is located in western Saudi Arabia, in a more comprehensive manner. To acquire deep geophysical data that can be used for imaging the geothermal system, we carried out a 3D magnetotelluric (MT) survey surrounding the Ain Al-Harrah hot spring.
Broad-band MT soundings in the period range of 0.001-500 seconds have been acquired at 50 sites around the Ain Al-Harrah hot spring with an average site spacing of 400 m. In addition, several transient electromagnetic (TEM) data are used to correct the static shift effect on the MT data. The measured MT data were processed using a well-validated robust statistical technique to estimate transfer functions for each sounding. Phase tensor, skew angle, and tipper were also calculated and analyzed. For interpreting the data, 3-D inversion of both impedance tensors and tippers was performed using the well-established ModEM algorithm.
Phase tensor representations and the calculated skew angles indicate a 2D and 3D subsurface conductivity structure. Thereby, a three-dimensional inversion of MT data is carried out. The data is fitted with an overall error-weighted RMS of 2.9 after 186 iterations. The 3D inversion results successfully image the geothermal features, such as the heat source, convection patterns, and groundwater system of the Ain Al-Harrah geothermal system. However, only the clay cap is not imaged in the 3D model. This is common in some cases at high-temperature volcanic-associated geothermal systems. The individual protrusions indicate the pathways either to the surface or to the near subsurface that would lead to an active geothermal surface manifestation (hot spring). We conclude that the thermal reservoir indicated by the conductive zone (100 ohm.m) is shallow at 2.1 km depth with a diameter of more than 4 km wide. While the MT survey suggests promising locations, only drilling operations can confirm the geothermal potential.
This study delivers the first 3-D model of subsurface electrical conductivity structure in the Al-Lith region, Saudi Arabia. In terms of geothermal exploration, this deep electrical conductivity model serves as the key input to understanding the characterization of the geothermal system.
Al-Hassa city contains the largest oasis in Saudi Arabia and one of the world's largest naturally irrigated land. 280 natural springs provided massive groundwater discharging and watering of agricultural land. Moreover, the water in some of the springs is used to be warm. The quality was also spatially varied. The characteristics above indicate a complex subsurface that has to be characterized. Four geophysical methods were applied to reconstruct a 3D subsurface for the study area.
Four non-seismic geophysical methods were applied, to reconstruct with the highest accuracy, a 3D model of the subsurface of the study area. Five hundred seventy-one gravity stations were acquired, covering the whole Al-Hassa Oasis, an area of 353 Km2. 46 magnetotelluric-MT stations, 6 audio-magnetotelluric-AMT stations, and 36 transient electromagnetic-TEM stations were acquired within the Al-Hassa National Park to reconstruct a 3D subsurface model. All EM soundings were processed and combined to achieve the highest resolution from the surface till the maximum depth of investigation. Gravity data were processed and lately integrated with the final 3D EM model.
Preliminary 1D modeling of the TEM data till the maximum depth of 200m shows a lateral discontinuity of resistivity, which agrees with spatial variation of the EC of groundwater samples in the study area. 2D and quasi-3D modeling of the MT data acquired along a N-S profile and 2 E-W profiles clearly show a salt dome structure that agrees with the low resistivity (brine) shallow water analysis and previously published paper. 3D modeling of the gridded gravity data acquired covering the whole Al-Hassa Oasis agrees with the expected NNW-SSE and ENE-WSW fracture zones that probably act as pathways or barriers to groundwater. All acquired geophysical data and collected geochemical data in the broader study area will be imported into PETREL and integrated to provide a more precise indication of the complexity of the study area.
The 3D geophysical subsurface modeling of Al-Hassa Oasis reveals a complex underground structure. The integration of various geophysical data sets, including TEM, MT, and gravity data, uncovers lateral discontinuities in resistivity, a salt dome structure, and fracture zones acting as pathways or barriers to groundwater flow. This comprehensive modeling approach provides valuable insights into the subsurface dynamics of the oasis, contributing to a better understanding of its hydrogeological characteristics and potential water resources management strategies.
With its 2030 vision, Saudi Arabia initiated reducing its dependence on fossil-based energy with renewable energy development, including geothermal resources, a very high priority. Previous studies have shown that Saudi Arabia has promising geothermal resources. The most prominent sites are located around Al-Lith, with four hot springs, where Ain Al-Harrah has the highest temperature and may provide the Al-Lith region with long-term electricity. Our key objective is to explore more comprehensively the prospect of geothermal resources around the Ain Al-Harrah hot spring with multi-physics. Electromagnetic (EM) methods cover a variety of applications during the energy transition and the development of renewable resources, including geothermal energy in Saudi Arabia. EM techniques are increasingly utilized to explore and characterize geothermal reservoirs for energy production or cooling/heating purposes. To achieve this goal, we are carrying out multi-physics measurements in the area and report initial results here. With the plan of drilling several wells, we initially used magnetotellurics to prepare for more detailed deep Controlled Source ElectroMagnetics later. The broadband magnetotellurics (MT) data in the period range 0.001-60 s for three different sampling frequencies were acquired using KMS-820 acquisition systems. Transient Electromagnetic (TEM) and Audio-Magnetotelluric (AMT) soundings were also collected to correct the possible static shift effect on the MT data. All the collected frequency and time-domain EM data were of high-quality. There are also initial 3D gravity results. Τhe 2D and 3D inversion results indicated similar results from top to bottom, five noteworthy features: (1) a near-surface low-resistivity (50-100 ohm.m) zone with an average thickness of Ashadi et al. less than 100 m, which can be interpreted as sediments fully saturated with freshwater (2) a medium to high resistivity unit (900-3000 ohm.m) appear at different depths, from 100-4000 m below the surface, representing the fractured basement, (3) a very high resistivity body (3000-7000 ohm.m) associated with the basement, (4) the low resistivity zone (60-125 ohm.m bulk resistivity) representing the geothermal fluids plume moving upward from the depth of 5-6 km below the surface, through the fractures (high permeability) zone reaching the depth of 500 m below the surface creating a convection cell, and (5) the hot-body with very low resistivities, 10-30 ohm.m, at the average depth of 6.5 km below the ground surface. Moreover, it is important that the surface manifestation of hot springs with a temperature of about 70-80 o C, also exists in this area. However, only drilling operations will reveal the geothermal potential, while the MT survey points to new drill locations. In the end, to gain deeper insight into the geothermal system, there are two main recommendations for any future research in the Al-Lith area as follows: (1) to conduct CSEM data acquisitions to gather high-resolution dense spatial data and provide an enhanced 3D subsurface image, and (2) to drill an exploratory well till the depth of 1 km to confirm the preliminary conceptual geophysical model and improve the interpretation of the collected data by applying constraint inversion.
