An-Najah Staff

Different pollutants from industries leach every day to soil and ground waters without treatment. The product N,N-bis (3,5-Dimethylpyrazol-1-yl methyl)-3-aminopropyl Polysiloxane (Si-C3H6NPz2) was successfully prepared. The FTIR results confirmed that the dimethylpyrazole units have been immobilized onto the surface of the modified silica gel. The adsorption experiments were conducted for a wide range of solution pH, adsorbent dosage, temperature, initial concentration and contact time. It was observed that the percentage removal of methylene blue dye decreased with an increase initial concentration and temperature while it increased with increase in solution pH, contact time and adsorbent dose. Over 82% removal efficiency of methylene blue dye was achieved after 180 min at solution pH around 10, 20°C temperature, 0.25 g weight of dose and initial concentration of 15 mg/L of 50mL MB dye solution.  Negative ∆G° values (-17.17 to -17.25 KJ/mol) indicate that the adsorption is favorable and spontaneous at these temperatures. The negative value of ∆H° (-16.66 KJ/mol) reflects an exothermic adsorption and indicates that the adsorption is favored at low temperature. The value of ∆H° was higher than those corresponding to physical adsorption. This would suggest that the adsorption process is chemical in nature. The small positive value of ∆S° (+1.78 J/mol.K) suggests that some structural changes occur on the adsorbent and the randomness at the solid/liquid interface in the adsorption system increases during the adsorption process. The results of the present study show that the prepared compound has a negative biological activity against Pseudomonas aeruginosa, Staphylococcus aurous, and Escherichia coli. 

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.