Assessment of the operational performances of two activated sludge systems in Kuwait.

Activated sludge systems (ASSs) are the most globally used wastewater treatment systems. However, there is very little information about the operational practices of ASSs in developing countries. This paper presents how the Riqqa and Umm-Al-Haiman ASSs, in Kuwait, are operated and the methodology used to evaluate and compare their performances. Over a period of 9 months, weekly samples of the influents, aeration tank mixed liquors, and secondary effluents were collected and analyzed according to standard methods. Accordingly, the operational variables of the systems were estimated. The obtained results indicate that the plants were not operated within their recommended design values. The Riqqa ASS was inadequately aerated and hydraulically and organically overloaded, while the Umm-Al-Haiman ASS was operated at a very high mixed liquor suspended solids (MLSS) value. The method used by this study proved to be useful for identifying the operational problems of the studied ASSs, and it can be used to evaluating the performances of other ASSs.