Khalil M. Ibrahim

New K-Ar ages of basalts from the Harrat Ash Shaam volcanic field in Jordan: Implications for the span and duration of the upper-mantle upwelling beneath the western Arabian plate

The volcanism in the western Arabian plate extends from the Red Sea through the Harrat Ash Shaam system to western Syria, as far north as the Bitlis suture in the Taurides. The Harrat Ash Shaam volcanic system in Jordan consists of northwest-trending dikes and a volcanic field that together encompass a width of 220 km. In terms of width, direction, and age of the main volcanic phases, the system is similar to the Red Sea dike belt. About 130 new K-Ar age determinations show that the ages of the Harrat Ash Shaam system (dikes and flows) range from Oligocene to Quaternary. However, there is a distinct gap in the ages between ∼22 and 13 Ma. This gap coincides with an apparent decrease in volcanism in the Red Sea region from around 20 to 12 Ma. We interpret this 9 m.y. gap as a quiescent period interrupting the volcanic activity in the region and suggest that from ∼22 to 13 Ma, tectonic activity in the Arabian plate was mainly restricted to the Red Sea region. A renewal of volcanism along the western margins of the Arabian plate at 13 Ma was very likely associated with the sinistral movement along the north-trending Dead Sea transform. This renewal of volcanism and tectonic activity may reflect the emergence of upper-mantle upwelling beneath the western Arabian plate at that time.

Removal of paraquat from synthetic wastewater using phillipsite–faujasite tuff from Jordan

A phillipsite-faujasite tuff (faujasite) from Jordan has been activated and characterized to evaluate its efficiency in removing paraquat from synthetic wastewater and to specify optimum conditions with maximum efficiency of the faujasite tuff. Noticed variation in CEC is indicated and explained by selectivity of the faujasite to K(+) and Na(+). Removal of paraquat by using faujasite directly gave average removal efficiency equal to 59%. Thermal activation of the samples enhances their performance. The higher is the temperature of activation the higher the efficiency. Treatment of paraquat effluent using faujasite is a good alternative. Na- or K-loading of the original sample give better results. Loading with Ca and Mg however is not recommended because they always exhibit lower efficiency, which might be related to their lower CEC value. Removal of paraquat from wastewater using charcoal and the non-activated faujasite increased efficiency to about 82%. Thermal activated faujasite at 200 degrees C and 300 degrees C increased the uptake up to about 93% and 99.5%, respectively. Therefore thermal activation of faujasite is necessary to improve its uptake performance.

Experimental investigation of effects of oil shale composition on its calorific value and oil yield

This paper reports results of a detailed geochemical analysis carried out on representative oil shale samples obtained from the Attarat Um Ghudrandeposit, in Jordan. The conducted tests aimed to determine main features of the studied samples, such as oil yield, calorific value, organic and inorganic composition and moisture content. Based on obtained results of a large number of oil shale samples, as received without any treatment, it was found that as other types of oil shale, elsewhere, Attarat Um Ghudran oil shale consists of several major constituents. These are organic matter, biogenic calcite and apatite, detrital clay minerals, and quartz. The effect of borehole depth, total carbon (TC), organic carbon (OC), and total sulphur content (TS) on the calorific value and oil yield were studied and analysed. Results were well correlated (with relatively acceptable correlation coefficients of about 0.9) according to the following equations for the calorific value and oil yield, respectively. Gross calorific value (kcal/kg) = - (478) + (106) OC + (59.2) TS + (21.8) TC Oil yield (% wt) = - (1.12) + (0.597) OC + (0.471) TS + (0.115) TC (Received: Feb 21, 2011; Accepted: March 29, 2011)

Comparative evaluation of the most common kriging techniques for measuring mineral resources using Geographic Information Systems

This study evaluates and compares the performances of ordinary, simple, universal, and disjunctive kriging techniques for measuring mineral resources using geographic information systems. These techniques differed in terms of their relative complexities, underlying assumptions, and analytical goals. The methodology consisted of selecting the best kriging techniques, based on their performances in the validation stage, for estimating the depth, thickness, and mass of a mineral resource by interpolating four surfaces representing the surface topography, mineral resource grade, and elevations of the upper and lower surfaces of the mineral resource. The methodology was tested on a phosphate layer detected in the Al-Abiad Mine in Jordan. The total measured phosphate resources were found to be about 1.3 million metric tons. They existed at depths varying from 6.9 to 19.4 m below the ground surface and had thicknesses ranging from 0.2 to 2.3 m. However, it can be concluded that the more complex the spatial behavior of the surface, the more complex is the kriging technique needed to interpolate that surface. Moreover, the deeper and thicker the mineral resource and the denser the spatial distribution of the exploration boreholes, the larger are the relative accuracies of the chosen kriging techniques for interpolating the required surfaces and the greater are the relative accuracies of the estimated depth, thickness, and mass of the mineral resource.

Application of Jordanian faujasite-phillipsite tuff in ammonium removal

Faujasite-phillipsite tuff (FAU) from Jabal Hannoun area was evaluated in ammonium removal from wastewater compared with chabazite-phillipsite tuff (CHA) from Tell Rimah area. Both samples are characterized by good physical and chemical properties, which enable them to be used as ion exchangers under column operation condition. In the presence of considerable concentration of competing ions such as Na+, Ca+2, K+ and Mg+2 under conditions of different ammonium concentrations, the FAU exhibits successful performance in removing NH4+ from wastewater compared with the efficiency of CHA for 50 and 25 mg NH4+/1 concentration. The study indicates that the efficiency of the FAU is about 2.2 to 2.0 times greater than CHA. Unlike the selectivity series of pure natural phillipsite and synthetic faujasite reported in the literature, FAU selectivity series is: Mg+2>K+>Ca+2>NH4+. This study remarks that regeneration of the FAU samples with Na using column operation is far more efficient than Na-loading by soaking in concentrated NaCl solution. In this regard, a considerable enhancement in the performance of regenerated FAU samples exceeds 100% is noted compared with their performance in the other experiments.

The degree of readiness of students of the University of Jordan to cope with future challenges entailed by the application of mobile learning in the educational field

The degree of readiness of students of the University of Jordan to cope with future challenges entailed by the application of mobile learning in the educational field.

Characterization of Jordanian Porcelanite Rock with Reference to the Adsorption Behavior of Lead ions from Aqueous Solution

Lead ions were adsorbed from aqueous solution by Jordanian porcelanite rock. Adsorption was studied as a function of initial concentration, PH, adsorbent dose and contact time at constant temperature. The equilibrium process was described by Langmuir and Freundlich isotherm model with maximum sorption capacity equal to 19.562 mg g-1, removal efficiency of 95 – 98% at about 40 min. of contact time, with 0.5 g of porcelanite and 10 – 30 ppm concentrations in metallic solutions. The physical and chemical characterization of porcelanite was carried out using X-Ray Fluorescence, X-Ray Diffraction, Scanning Electron Microscope and Thermogravimetry analysis. The specific surface area has also been investigated. The Jordanian porcelanite rock represents an alternative natural adsorbent, since it is a low cost material and has the ability to be used as an adsorbent for the removal of toxic inorganic materials from water.

Inverse geochemical modeling of groundwater salinization in Azraq Basin, Jordan

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.

Characterization and utilization of solid residues generated upon oil and heat production from carbonate-rich oil shale

Abstract The utilization of a newly discovered Jordan-origin oil shale was outlined in this work. Both industrial and environmental issues were discussed for better handling the wastes that often generated upon processing of oil shale. Two by-products of oil shale were studied, retorted, and combusted oil shale. The wastes were produced under different conditions. Different analytical techniques (XRF, XRD, proximate analysis, infrared spectroscopy, particle size distribution, TGA/DSC, and ultimate analysis) were used to follow up the physicochemical changes in generated solid residues. Oil shale was rich in carbonate with spent content of 73.2%. Upon processing oil shale, many heavy metals were concentrated in the final residue. The most concentrated metals were Cr, Cu, Co, and V with enrichment factor more than 2.0 in both residues. Compared with raw oil shale, leaching of toxic heavy metals was increased many folds and percentage of extraction was higher than 60% of all metals using HNO3. Total characteristic leaching tests TCLT, a standard test to stimulate metals elution in the environment, confirmed that retorted oil shale was more toxic when contacted with aquatic environment. TCLT indicated that the released amount of Cr was 4.4 higher than the safe limit set by international agencies. Elemental analysis indicated that H/C ratio of oil shale was 0.11 and hence would be used as low-grade fuel. The maximum content of kerogen was 19%, which is estimated by Soxhlet extraction with methanol. The best utilization of retorted and combusted solid residues was as solid medium for Pb ions and phenol removal from solution. Retorted oil shale has better efficiency toward phenol, while combusted oil shale exhibited better removal for Pb ions. Gross heating value, textural parameters, density, and Si/Al ratio were found useful indicators to assess the best utilization of solid wastes generated upon oil shale processing.