Hussein Allaboun

Adsorption of Phenol on Different Activated Carbons Prepared from Date Pits

The potential use of different activated carbons (ACs) prepared from dates pits and phosphoric acid for the removal of phenol from aqueous solutions was investigated. Date pits were converted into five different types of activated carbons by air and phosphoric acid activation. The specific surface area (BET) of the prepared ACs varied from 794 m2/g, for the phosphoric acid:date pit ratio of 5:1, to 1707 m2/g for a ratio of 2:1. Batch adsorption experiments revealed that the adsorption of phenol varied among all of the prepared ACs, where the 2:1 AC showed the highest uptake. Equilibrium pH studies showed that the phenol removal was pH dependent and the maximum phenol uptake occurred at an equilibrium pH of 3.0. Dynamics studies indicated that the initial uptake of phenol on 2:1 AC at pH 4 was rapid, where 80% of the maximum uptake was achieved during the first 30 minutes; both surface adsorption and intraparticle diffusion were involved in the adsorption process and the data followed the pseudo second-order reaction. The equilibrium adsorption data of phenol on 2:1 AC at solution pH 3 was best described by the Redlich-Peterson, Sips, and Langmuir models.

Removal of 4-Chlorophenol from Contaminated Water Using Activated Carbon from Dried Date Pits: Equilibrium, Kinetics, and Thermodynamics Analyses

Five different activated carbons (ACs) have been prepared from dried date pits using air and phosphoric acid as activating agents. The used phosphoric acid:date pit ratio dictated the characteristics of the prepared ACs; the equivalent BET-nitrogen surface area varied from 794 m2/g for a ratio of 5:1, to 1707 m2/g for a ratio of 2:1, whereas the micropore volume changed in value from 0.24 cm3/g for the 5:1 ratio to 0.59 cm3/g for the 2:1 ratio. The prepared ACs were tested to remove 4-chlorophenol (4-CP) from aqueous solutions by means of batch adsorption process. The prepared 2:1 AC exhibited the highest uptake with a maximum of 525 mg/g. Equilibrium pH studies showed that 4-CP removal was pH dependent; the maximum uptake occurred at an equilibrium pH value of 5.5. Dynamic studies showed that 4-CP uptake on 2:1 AC is rapid, with 80% of the maximum uptake achieved during the first 40 min. Both surface adsorption and intraparticle diffusion were identified to be effective adsorption mechanisms. Kinetic studies indicated a pseudo second-order reaction. Results of equilibrium adsorption experiments showed that the adsorption of the 4-CP on 2:1 AC is best described by the Langmuir model. The thermodynamics parameters of the adsorption (ΔG0, ΔH0, and ΔS0) were determined by studying the adsorption equilibrium at different temperatures. The values of these parameters indicated the spontaneous and endothermic nature of the adsorption phenomenon of 4-CP on the prepared ACs.

VAPOR-LIQUID EQUILIBRIUM DATA OF CHLOROFORM-ETHANOL MIXTURES INSIDE POLAR AND NONPOLAR POROUS PLATES

Vapor-liquid equilibrium (VLE) data of chloroform-ethanol mixtures at different temperatures were experimentally measured in 3 different macroporous plates: a 13.5-μm pore diameter, sintered, stainless-steel plate; a 30-μm pore diameter, porous, carbon plate; and a 30-μm pore diameter, porous, Teflon plate. The experimental results showed that the VLE of this system in the stainless steel plate was dramatically altered and the azeotropic point was eliminated. However, the effect of the porous Teflon plate or porous carbon plate on the VLE of this system was insignificant. The VLE for the studied system was predicted through the theory of Abu Al-Rub and Datta and gave a good agreement with the experimental data.

CO 2 Supercritical Extraction of Essential Oil of Jordanian Rosemary

Background: Experimental investigation of supercritical fluid extraction (SFE) of active ingredients from rosemary herb has been performed. Carbon dioxide (CO₂) was used as a solvent with ethanol as a trapping agent. This work showed that the SFE can be an exceptional alternative to the use of chemical solvents. Objective: The effect of temperature and pressure on the extraction process was investigated to increase the yield of the extracted essential components. Methods: The types of extracted compounds from rosemary were specified and analyzed using GC-MS. Results: The results indicated that several essential active ingredient compounds were extracted. Furthermore, the pressure affects the extraction, as the composition of some compounds increases with a pressure increase. Conclusions: SFE can be used to extract valuable active ingredients from rosemary. Two process parameters were investigated, namely, pressure and temperature, which indicate that SFE is a selective process for the production of certain constituents. Highlights: Some of the main components of the essential oil of Jordanian rosemary obtained in this study have important applications in pharmaceutical and cosmetic products. For instance, α-pinene is one of the main raw compounds used in the perfume industry.

Dynamic modelling and simulation of Kühni extraction columns

Abstract A robust rigorous mathematical model based on the population balance equation (PBE) is developed to predict the dynamic behaviour in Kuhni extraction columns; the developed model is extended to include the momentum balance equation to calculate the drop velocity. The effects of step changes in the important input variables (flow rates and rotational speed ( rpm )) on the transient holdup are investigated. The transient analysis reveals the fact that the response of the dispersed phase holdup is very fast due to the relative fast motion of the dispersed drops with respect to the continuous phase. The dynamic behaviour of the dispersed phase shows a lag time that increases away from the feed point. The predicted holdup dynamic profiles along the column height are compared to the experimental one where good agreement is achieved.