An-Najah Staff

In this study we examined the adsorption, kinetics and thermodynamics of heavy metals of used engine oil that come during engine operation and forsaw the possibility of polluting soil and ground water. the effect of temperature on
adsorption was investigated in the range (15 – 45o C) and results showed that maximum removal occurred at 45C. Effect of pH indicated that maximum removal of both Zn and Pb was at pH =13. Increasing adsorbent (soil) dosage from 0.5 to 3g showed that maximum adsorption of both Zn and Pb onto soil occurred with 3 g of soil. Equilibrium concentration happened at 90 minutes. Lanqmuir and Freiundlich models were used to study adsorption process at equilibrium and the
results showed that Frenundlich is better for Zn while Lanqmuir fits better with Pb. In order to investigate adsorption behavior of Zn and Pb on soil, three kinetic models applied; Pseudo-first order, Pseudo-second order and intra- particle diffusion models were applied to fit kinetics data. The rate constants and correlation coefficients were determined for the three models. Thermodynamic parameters such as Gibbs free energy, standard enthalpy and standard entropy change were calculated for both zinc and lead.

Several factors affecting the growth and the metal uptake of pepper plants treated with cadmium solutions have been studied. These include concentration of cadmium, type of treatment, type of soil, plant species, and some properties of solutions used for treatment such as acidity, degree of salinity and temperature.
Cadmium had an obvious effect on the growth of pepper plants. Foliar‐treated plants were affected more than root‐treated plants. The least degree of growth‐inhibition and of cadmium uptake was found in plants grown in soils with high organic matter content. Various species of pepper plants acted very differently towards cadmium treatment. Both growth‐inhibition and cadmium uptake was increased in plants treated with acidic, saline and hot solutions.

Several factors affecting the growth and the uptake of cadmium by okra plants were studied using both root ‐ treatment and foliar ‐ treatment. These factors were the concentration of cadmium , type of treatment, soil composition, presence of foreign ions, salinity, acidity and temperature.
Both growth of plant and cadmium uptake by plant were affected highly by the concentration of cadmium, type of treatment, soil composition, salinity and temperature. Acidity of solutions has only a little and irregular effect. A synergistic combined effect of lead, copper and zinc with cadmium was observed on the growth of plant but not regular on the uptake of cadmium.

Differential-pulse adsorptive cathodic stripping voltammetric (DP-AdCSV) and high performance liquid chromatography (HPLC) techniques were developed for quantitative determination of Reactive Blue 19, Reactive Red 198 and Reactive Orange 107 textile dyes. The calibration curves using the DP-AdCSV method were found to be linear over the ranges 0.05-1.0 ppm, 0.10-1.10 ppm and 0.05-1.0 ppm, respectively. The HPLC method is based on using a mobile phase consisting of acetonitrile:water (60:40, v/v) containing 0.45 M N-Cetyl-N,N,N-trimethylammonium bromide (CTAB) and buffered to pH 7.92. Reverse phase RP C18 column was used with a flow rate of 0.6 ml/minute. The retention times for Reactive Blue 19, Reactive Red 198 and Reactive Orange 107 were found to be 5.4 min, 7.8 min and 2.3 min, respectively. The calibration curves were found to be linear over the ranges 0.1-5.0 ppm, 0.1-1.2 ppm and 0.05-1.5 ppm, respectively.

Pollution of the aquatic environment by human and veterinary waste pharmaceuticals is an increasing area of concern but little is known about their ecotoxicological effects on wildlife. In this study, three pharmaceuticals were selected (ibuprofen, amoxicillin and caffeine) as examples that are released in the environment. All of them are marketed in the Palestinian market (Pharmacies), private clinics and hospitals. The adsorption of the selected pharmaceuticals was examined by batch sorption experiments onto agriculture soil. Pharmaceuticals adsorption kinetics followed the pseudo-second-order adsorption model. Adsorption isotherms were best fitted by the Freundlich isotherm model. The “n” parameters were higher than 1 and the K_f values for all of them were less than 1. High removal rates of amoxicillin and ibuprofen were achieved in acidic media (pH = 1-4) and reached more than 88% Except for the caffeine increased at higher pH and reached more than 92%. The thermodynamics parameters showed that the adsorption process on soil was spontaneous and exothermic.

Present methods of analysis and mathematical modeling contain so many assumptions that separate them from reality and thus represent a defect in design which makes it difficult to analyze reasons of failure. Three dimensional (3D) modeling is so superior to 1D or 2D modeling, static analysis deviates from the true nature of earthquake load which is “a dynamic punch”, and conflicting assumptions exist between structural engineers (who assume flexible structures on rigid block foundations) and geotechnical engineers (who assume flexible foundations supporting rigid structures). Thus a 3D dynamic soil‐structure interaction is a step that removes many of the assumptions and thus clears reality to a greater extent. However such a model cannot be analytically analyzed. We need to anatomize and analogize it. The paper will represent a conceptual (analogical) 1D model for soil structure interaction and clarifies it by comparing its outcome with 3D dynamic soil‐structure finite element analysis of two structures. The aim is to focus on how to calculate the period of the structure and to investigate effect of variation of stiffness on soil‐structure interaction.