الفهرس 
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Abstract
The effect of hydrodynamic conditions on the rate of CU+2 removal from synthetic waste of copper sulphate solution by cementation on a fixed bed of zinc cylinders was investigated under different conditions of: solution flow rate (velocity), initial copper sulphate concentration, bed height, cylinder diameter, and solution temperature. The values of the mass transfer coefficient were found to increase with increasing solution velocity and temperature but those values were found to decrease with increasing bed height, cylinders diameter and initial copper sulphate concentration. The value of the activation energy of the reaction was found to be in the range from 2.5 to 4.60 kCal/mol with lower and higher solution velocity respectively which shows that the reaction is a diffusion controlled one.
The effect of drag reducing polymer such as Polyox WSR-301 and Separan AP-30 on the rate of mass transfer was studied, and it wc!s found that a percentage reduction of 10 to 30% for Polyox WSR-30 I and from -5 to 15 % for Separan AP-30 were obtained for lower and higher initial concentrations of drag reducing polymer respectively. Also, the effect of surfactant such as Triton X-I 00 was studied and was found to drastically reduce the rate of mass transfer from 35 to 63% at concentration of Triton ranging from 25 ppm to 75 ppm respectively, while higher concentration of Triton X-I 00 (> 75 ppm) cannot be studied due to high foaming.
The mass transfer correlation was deduced by dimensional analysis and it was found to be in the form that:
Sh = 2.1 Re0.867 Sc0.33 (d/h)-1.02
Also, another correlation was deduced for the effect of entrance region by emoving the calming section which was found to be in the form that:
Sh = 2.1 Re0.870 Sc0.33 (d/h)-0.96