المجلة الدولية للعلوم والتقنية

This paper investigates the kinetics of organic removal by non-coated Cosmo ball biomedia and activated carbon-coated Cosmo ball biomedia in the bioreactors for domestic wastewater treatment. The Modified Stover Kincannon Model and Grau Model were employed for the kinetic evaluation of the reactor performance during the operational period. The Stover Kincannon Model gives a coefficient of determination (R2) for the straight lines of effluent concentration from the experimental data. The Stover Kincannon gives a predicted BOD5 of 0.98 and 0.99 for the coated and non-coated media, while the values given by the Grau Model are 0.98 and 0.99. The predicted COD for the coated and non-coated media for the Stover Kincannon Model are 0.98 and 0.99 and 0.99 and 0.99 for the Grau Model.The predicted BOD5 for the modified Stover-Kincannon Model are 〖 K〗_B= 0.68 g/L.d and U_(max=) 0.55 g/L.d, while the corresponding values for COD are 〖 K〗_B= 4.61 g/L.d and〖 U〗_max= 3.42 g/L.d for the non-coated Cosmo balls. The BOD5 for the coated Cosmo ball are K_B= 2.46 g/L.d and〖 U〗_max= 2.33 g/L.d, and the COD are K_B=5.74 g/L.d and 〖 U〗_max=4.9 g/L.d. For Grau model the (K_s) for the BOD and COD of the non-coated Cosmo balls are 0.062 d-1 and 0.40 d-1, and the BOD5 and COD of the coated Cosmo balls are 0.289 d-1 and 0.836 d-1. The results showed that the Stover-Kincannon model is the best kinetic model.