Kamal Al-Malah

Olive mills effluent (OME) wastewater post-treatment using activated clay

Olive mill effluent (OME) wastewater embodies a challenge for environmental scientists and engineers. It is characterized by high values of COD, BOD, and phenolic content. A series of treatment steps composed of settling, centrifugation, and filtration was consecutively used to condition OME wastewater. The filtrate was then subjected to a post-treatment process, namely adsorption on activated clay. The dynamic response of phenols concentration, pH, and COD, using different concentrations of activated clay, showed a peak at which maximum adsorption capacity was achieved. The maximum adsorption capacity for the tested concentrations of activated clay was reached in less than 4 h. It is thought that adsorption of phenols and organics is reversible and mainly due to hydrophobic interactions. The maximum removal of phenols was about 81%, while it reached about 71% for organic matter.

Heat effect on rheology of light- and dark-colored honey

Abstract The effect of temperature and time of constant temperature heating ( t CTH ) on the rheological properties of light and dark types of honey was examined. Honey samples were heated up to 40°C, 60°C, 80°C or 94°C, and hold for 5, 10 or 20 min, and their viscosities were then measured either immediately at the heating temperature or after being cooled overnight, where measurements were carried out at 25°C and 35°C as a function of the shear rate. The types of honey used were identified via assessing the source of the nectar using pollen analysis (Melissopalynology). It was found that both honey types behave like a Newtonian fluid regardless of the conditions of heating. The time of heating required to reach the desired ultimate temperature correlates with the water content of the fresh, untreated sample. A light-colored, low water-content, heat-treated honey showed a change in viscosity only at higher heating temperatures when compared with the fresh untreated control sample. On the other hand, a dark-colored, heat-treated honey showed a change in viscosity at all levels of heating temperature. In general, the viscosity of a heat-treated honey increases with increasing ultimate heating temperature and t CTH .

RHEOLOGICAL PROPERTIES OF SELECTED LIGHT COLORED JORDANIAN HONEY

The rheological properties of Apple, Besromia, Citrus, and Ziziphus types of light colored Jordanian honey were examined. The types of honey used were identified via assessing the source of nectar using pollen analysis (Melissopalynology). The moisture content of honey samples was indirectly assessed via measuring the refractive index of the sample using a refractometer. A rotational, concentric cylinder viscometer was used to measure rheological properties of honey samples. The apparent viscosity was measured as a function of the shear rate. In addition, the apparent viscosity was measured, at constant shear rate at 2.2 s−1, as a function of shearing time. Newtons law of viscosity was found to adequately describe the flow behavior of honey samples. The apparent viscosity was found to decrease with temperature, and the temperature dependency of viscosity was found to follow the Arrhenius model. Moreover, the viscosity was also found to decrease with moisture content of honey. An exponential fit was used to describe the water content dependency of viscosity.

Effect of glucose concentration on the rheological properties of wheat-starch dispersions

The effect of glucose addition and time of constant temperature heating (tCTH) on the rheological properties of starch dispersion systems was examined. A fixed starch mixture of 5% (w/v), and glucose concentrations of 0‐6% (w/v) were used. The starch dispersion was heated up to 808C, then was kept, at this temperature, for a period of 0, 10, 20, or 30 min. The apparent viscosity was then measured as a function of shear rate. In addition, the apparent viscosity was measured, at constant shear rate of 106 s 21 , as a function of shearing time. The Herschel‐ Bulkley model Ota t0 1 m_ g n U was used to fit the flow behavior of starch dispersions. It was found that the flow behavior index, n, approaches unity (Bingham model) for most of the data. It was also found that as tCTH was increased, for a given glucose concentration, both yield stress, t 0, and consistency coefficient,m, increased. The presence of glucose also resulted in an increase of both t 0 and m .A t 6% glucose concentration, samples with tCTH of 30 min showed the highest anti-thixotropic behavior. The apparent viscosity of starch dispersions at tCTH of 0 min had the lowest value at all levels of glucose concentrations. In general, the presence of glucose resulted in an increase in the apparent viscosity compared to that of glucose-free starch dispersions. q 2000 Elsevier Science Ltd. All rights reserved.

Dynamic Post-treatment Response of Olive Mill Effluent Wastewater Using Activated Carbon

Abstract Olive mill effluent (OME) wastewater represents a serious environmental problem in the Mediterranean area. It has extremely high values of COD, BOD, and phenolic content. A new approach of treatment steps composed of settling, centrifugation, and filtration is suggested to be used to condition OME wastewater. The filtrate is then subjected to a post-treatment process, namely adsorption on activated carbon. The dynamic response of phenols concentration, pH, and COD, using different concentrations of activated carbon, shows a peak at which maximum adsorption capacity is achieved. The maximum adsorption capacity for the tested concentrations of activated carbon is reached in less than 4 h. The maximum removal of phenols is about 94%, while it reaches about 83% for organic matter.

Study on Bentonite-Unsaturated Polyester Composite Materials:

Jordanian Ca-bentonite was used in formulation of unsaturated polyester-based composite materials. For curing purpose, methyl ethyl ketone peroxide was used as an initiator and it was accelerated with cobalt octoate to maximize the curing process at room temperature. The effect of filler and styrene contents on the physical properties of composites was assessed by measuring the compressive strength, hardness, thermal conductivity, water absorption capacity, and apparent density. Increasing the filler content, at a constant styrene/polyester ratio, increased the properties of composites. On other hand, maximum values of compressive strength, hardness, and thermal conductivity of composites were found at about 22.7 wt% of styrene, whereas water absorption capacity was minimum at a styrene content of 32.8 wt%. Nevertheless, the apparent density was found to linearly decrease with styrene content.

Emulsifying properties of BSA in different vegetable oil emulsions using conductivity technique

The stability of oil in water emulsions using bovine serum albumin (BSA) as an emulsifying agent was investigated using the conductivity technique. The effect of oil volume fraction (0.25‐0.56 v/v) and BSA concentration (0.05‐5.00 mg/ml) was studied using four vegetable oils, namely corn, olive, soybean and sunflower. In general, it was found that the effect of increasing BSA concentration from 0.05 to 5.0 mg/ ml on emulsion stability showed a systematic behavior characterized by a decrease followed by an increase and then by a decrease. Moreover, corn oil showed no emulsification at low BSA concentration, and/or higher oil volume fraction (w o). Unlike other oils, olive oil could be emulsified to higherw o. As far as w o is concerned, emulsion stability showed an increase with increasing w o. Finally, emulsifier activity showed a weak dependence on BSA concentration, while increasing w o positively affected the emulsifier activity. q 2000 Elsevier Science Ltd. All rights reserved.

Jordanian Clay-Based Heat Insulator Composites: Mechanical Properties

In this study formulation of composite materials was made using different types and compositions of Jordanian fillers of virgin, untreated bentonite, and feldspar. Unsaturated polyester liquid blended with the filler with a given polyester/filler ratio was transformed into solid upon thermo-set process using chemical reagents to initiate the thermo-set process, and later control the propagation and termination steps. The solid samples produced were then subjected to mechanical, thermal conductivity, and water absorption tests to come up with a product formulation having best or optimum properties in terms of previously tested characteristics. In this paper, the results of the mechanical tests will be presented. In brief, it was found that mechanical properties did improve with increasing clay weight percentage up to 60 wt%. Beyond 60 wt% the product formulation was found to be inconsistent and non-reproducible. Furthermore, it was found that a composite material based on a certain type of clay (with highest content of Al2O3 and SiO 2), possessed superior characteristics in terms of mechanical properties and compared with calcium-carbonate-containing, polyester-based composite materials.

Microemulsions of Potassium Oleate, Tween-20, Propylene Carbonate, and Ethylene Glycol as Drug Vehicles for Mefenamic Acid

Different microemulsions were prepared with and without mefenamic acid (MFA). The base microemulsion was mainly composed of distilled water; the aqueous phase, propylene carbonate; the oil phase, potassium oleate; the surfactant, and finally di-ethylene glycol; the cosurfactant. The effect of mixing ionic (potassium oleate) with nonionic (Tween-20) surfactant was investigated via constructing the phase diagrams of such systems. Changes in conductivity and viscosity of the freshly prepared microemulsion over time were monitored as an indication for the stability of the microemulsion. Measurements were carried out at room temperature, after a freeze-thaw cycle and also after storage for 3 days at 60°C, where the latter is treated as an accelerated test for the time-temperature effects on the stability of a microemulsion. It was found that a set of surfactants, instead of a single surfactant, and inclusion of cosurfactant resulted in a broader region where a stable microemulsion is predominant. At a mass ratio of 1:2 of potassium oleate to Tween-20, O/W microemulsions were found to have maximum stability among all examined systems, under the accelerated test, such that they have a minimum portion of combined surfactants and cosurfactant of 60 wt% and maximum of 80 wt%. With the aforementioned specifications, no phase separation and neither significant change in the conductivity nor in the viscosity was observed in any of the examined systems after subjecting them both to the accelerated and freeze-thaw cycle test, indicating that such systems were thermodynamically stable. Samples of micro emulsions passing previous tests were further subjected to an acidic medium by dispersing 1 g of MFA-containing microemulsion in 10 g HCl solution (pH 1) in a shaking water bath at 37°C, for a 6 hour period. The maximum solubility of MFA in a stable microemulsion was approximately 5 wt%, evaluated at room temperature.

Jojoba Oil/Water Emulsions Stabilized by BSA and Egg Proteins: A Study Using Conductivity Technique

Stability of jojoba oil/water emulsion systems was investigated using the conductivity technique. Egg white, egg yolk, and bovine serum albumin (BSA) proteins were used as emulsifiers. Stability of above emulsions was investigated using several protein concentrations (0.05–0.50 mg/ml) and several oil volume fractions, OVF, (0.25; 0.50). It was concluded from the results that the investigated emulsions stability, when using BSA, was higher than when using egg white or egg yolk. In addition, emulsion stability did not show a strong dependence on OVF, except at the higher protein concentration of 5.0 mg/ml, where ES increased significantly with increasing OVF. Finally, emulsifier activity was found to increase with increasing OVF.