1. Senior Lecturer, Dept. of Chemical Engineering, Univ. of Benin, Benin City, Nigeria (corresponding author). E-mail: afaisen2002@yahoo.com
2. Senior Lecturer, Dept. of Chemical Engineering, Univ. of Benin, Benin City, Nigeria.
3. Professor, Dept. of Chemical Engineering, Univ. of Benin, Benin City, Nigeria.