Dr. Mustafa M. A-Faize, Worod M. Jabar, Hashim Sattar Shahd. 2021. “Effect of Surfactant on Hydrodynamic and Mass Transfer Charactersitics in Rotating Disc Contactor”. Design Engineering 2021 (04), 420 -34. http://thedesignengineering.com/index.php/DE/article/view/1376.