Calibration of ASM1 for Carbon and Nitrogen Removals of Riqqa Activated Sludge System, Kuwait

Abstract

Abstract-Riqqa plant, the second largest wastewater treatment plant in Kuwait, has lately shown signs of working under unstable conditions. The Kuwait Institute for Scientific Research has conducted a study to evaluate the plant performance and to pin-point the probable causes of the problem. To achieve these objectives, the Riqqa activated sludge system was modelled using activated sludge model No. 1 (ASM1) in SIMBA simulation package. It was the first time to use ASM1 to model a full-scale activated sludge system in Kuwait. This paper presents the calibration of ASM1 to carbon and nitrogen removals of the Riqqa activated sludge system, using long-term routinely measured wastewater quality parameters. Repirometery analysis was used to help in chemical oxygen demand (COD) fractionation and for providing initial guess values for the calibrated parameters. Validation results showed reasonable agreement between the measured and simulated COD, NH 4 -N and NO 3 -N over long-term dynamic simulation. The developed model was then used to evaluate and diagnose the system performance. The values of ASM1 parameters obtained will be useful in modelling other activated sludge systems in the country.