Abstract: A wastewater treatment method comprising splitting wastewater influent into a first influent stream and second influent stream; subjecting the first influent stream to treatment within at least one membrane aerated biofilm reactor (MABR) to provide a MABR effluent; subjecting the second influent stream and said MABR effluent to treatment within an anaerobic ammonium oxidation (Anammox) reactor to obtain treated water effluent; and discharging from said Anammox reactor said treated water effluent. Also provided is a wastewater treatment system comprising at least one membrane aerated biofilm reactor (MABR) module; an anaerobic ammonium oxidation (Anammox) reactor comprising at least one inlet and an outlet for discharging treated water effluent; and a wastewater influent arrangement configured for splitting a wastewater influent to a first influent stream and a second influent stream and for supplying said first influent stream to said MABR module and said second influent stream to said Anammox reactor.