Impact of reactor configuration on anammox process start-up: MBR versus SBR

► We used external membrane bioreactor (EMBR) to enrich slow-growing anammox bacteria. ► We assessed the start-up process (using EMBR) versus the widely-used SBR. ► Both molecular biology and specific activity tests were applied for comparison. ► We demonstrated that the EMBR performed better than SBR.