As　the　largest　single　energy-consuming　component　in　most　biological　wastewater　treatment　systems,　aeration　control　is　of　great　interest　from　the　point　of　view　of　saving　energy　and　improving　wastewater　treatment　plant　efficiency.　In　this　paper,　three　different　strategies,　including　conventional　constant　dissolved　oxygen　(DO)　set-point　control,　cascade　DO　set-point　control,　and　feedforward-feedback　DO　set-point　control　were　evaluated　using　the　denitrification　layout　of　the　IWA　simulation　benchmark.　Simulation　studies　showed　that　the　feedforward-feedback　DO　set-point　control　strategy　was　better　than　the　other　control　strategies　at　meeting　the　effluent　standards　and　reducing　operational　costs.　The　control　strategy　works　primarily　by　feedforward　control　based　on　an　ammonium　sensor　located　at　the　head　of　the　aerobic　process.　It　has　an　important　advantage　over　effluent　measurements　in　that　there　is　no　(or　only　a　very　short)　time　delay　for　information;　feedforward　control　was　combined　with　slow　feedback　control　to　compensate　for　model　approximations.　The　feedforward-feedback　DO　control　was　implemented　in　a　lab-scale　wastewater　treatment　plant　for　a　period　of　60　days.　Compared　to　operation　with　constant　DO　concentration,　the　required　airflow　could　be　reduced　by　up　to　8-15%　by　employing　the　feedforward-feedback　DO-control　strategy,　and　the　effluent　ammonia　concentration　could　be　reduced　by　up　to　15-25%.　This　control　strategy　can　be　expected　to　be　accepted　by　the　operating　personnel　in　wastewater　treatment　plants.