The　performance　of　three　pilot　scale　intermittent　aeration　membrane　bioreactors　(IAMBRs)　with　different　operating　phases　was　evaluated　over　a　long-term　operation.　Moreover,　the　effects　of　different　effluent　strategy　on　the　carbon　emission　and　economic　cost　of　the　reactor　were　analyzed.　The　results　show　that　the　average　removal　rate　of　organic　matter　and　total　phosphorus　(TP)　was　stably　above　90　%.　However,　the　single-point　continuous　inflow　led　to　the　uneven　distribution　of　carbon　source　and　nitrogen　in　the　anoxic　section,　which　inhibited　the　denitrification　process.　Therefore,　the　short-term　aeration　during　phase　II　was　conducted　to　enhance　the　denitrification,　and　the　result　showed　that　pre-aeration　significantly　improved　the　degradation　efficiency　of　NH3-N.　More　importantly,　the　carbon　emission　of　IAMBR　process　(Device　1　and　3　was　0.695　kg/m3　and　0.657　kg/m3,　respectively)　was　lower　than　that　of　traditional　activated　sludge　process,　MBR　process　and　AAO-MBR　process.　This　study　demonstrated　that　in　the　areas　with　low　effluent　quality　requirements,　the　intermittent　aeration　operation　with　gravity　effluent　could　be　a　better　selection　in　reducing　the　operating　costs　and　indirect　carbon　emissions.　©　2024　Elsevier　Ltd