“Modeling of Mass Transfer Coefficient in Rotating Biological Contactor with Perforated Discs (RPBC)”, alkej, vol. 11, no. 4, pp. 20–27, Dec. 2015, Accessed: Apr. 30, 2025. [Online]. Available: https://www.alkej.uobaghdad.edu.iq/index.php/alkej/article/view/271