الفهرس 
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Abstract
The purpose of this study is to develop a new heterogeneous liquid-solid batch reactor that can be used for diffusion controlled catalytic and non-catalytic reactions. The new cell consists mainly of a multi-cylinder rotating array which can be used as a catalyst support in catalytic diffusion reactions. The performance of the new cell was evaluated using an electrochemical technique involving the measurement of the limiting current of ferricyanide reduction at the cylinder array surface in presence of large excess of NaOH as supporting electrolyte. Recovery of copper from dilute solution was studied as an application of the new cell in the removal of heavy metals from effluent solutions. Variables studied included: i. Physical properties of the solution (ρ, µ, D).ii. Speed of rotation of the cylinder array. iii. Cylinder diameter (dc).iv. Distance between vertical cylinders (s).The study revealed the following results. i. The mass transfer coefficient increases with increasing the speed of rotation. ii. For a given speed of rotation, the mass transfer coefficient decreased with increasing the individual cylinder diameter. iii. The mass transfer coefficient was found to increase slightly with decreasing the spacing between successive cylinders in the range: 0.27 𝑠 𝑑< 0.57. iv. For a given set of conditions, a sharp decrease of the mass transfer coefficient was recorded when decreasing the spacing between cylinders beyond 𝑠 𝑑= 0.27. v. Mass transfer data was correlated using the method of dimensional analysis and the following mass transfer correlation was obtained: 𝑆ℎ = 2.3251 𝑆𝑐0.33 𝑅𝑒0.44 𝑑𝑐 𝑑 0.83 𝑠 𝑑 −0.07 For the conditions 16810 < 𝑅𝑒 < 198300, 1577 < 𝑆𝑐 < 3591, 0.08 < 𝑑𝑐 𝑑 0.16 𝑎𝑛𝑑 0.27 < 𝑠 𝑑 < 0.57 with ± 5.39% average deviation and 4% standard deviation vi. Mass transfer equation was further simplified neglecting the dimensionless ratio (s/d) to the following: 𝑆ℎ = 2.4876 𝑆𝑐0.33 𝑅𝑒0.44 𝑑𝑐 𝑑 0.83 For the same conditions with an average deviation ± 5.64% and a standard deviation 4.08%. vii. The highest rate of mass transfer was achieved using the 8 cylinders rotating array at 400 rpm.