Abdrabalamir Ahmed Al-Senan2022-05-182022-05-184793https://drepo.sdl.edu.sa/handle/20.500.14154/1575A field study was conducted at the 55 MGD Dammam wastewater treatment plant employing the carrousel system, to evaluate its overall performance with particular emphasis on nitrogen removal, 99% ammonia reduction, and 93% TKN removal. The plant readily met the secondary effluent BOD₅ requirement with an average BOD₅ concentration of 8.2 mg/l, but rarely satisfied the SS standard with effluent SS averaging around 29 mg/l. While the average total effluent nitrogen was 4.4 mg/l, nitrification - denitrification accounted for about 45% of the total nitrogen removal. The system kinetics for BOD₅ and ammonia removal conformed to the plug-flow first-order kinetic model. Kinetic parameters estimated in this study were well within literature values.enThesis