Continuous microalgae cultivation in aquaculture wastewater by a membrane photobioreactor for biomass production and nutrients removal

•Microalgae were cultured in aquaculture wastewater by newly developed MPBR.•Concentrated microalgae cultivation with diluted wastewater was achieved in MPBR.•MPBR could remove most of the nutrients with a short HRT of only 1 day.•Unionized ammonia was completely removed by microalgae cultivation in MPBR. An efficient continuous microalgae cultivation process for biomass production and nutrients removal from aquaculture wastewater was developed using a membrane photobioreactor (MPBR). Chlorella vulgaris and Scenedesmus obliquus were firstly batch cultured in aquaculture wastewater. C. vulgaris showed better performance with the specific growth rate of 0.17d−1 and was continuously cultivated in MPBR. The average volumetric biomass productivity in the MPBR operated at HRT of 1 day was 42.6mgL−1d−1, which was 5.8-fold larger than that achieved in batch cultivation in flask. Advanced nutrients removal from aquaculture wastewater was also achieved in MPBR. The average reduction in TN and TP was 86.1% and 82.7%, respectively, after stabilization. The corresponding effluent concentration was below 1.30 and 0.12mgL−1 for TN and TP, respectively. Unionized ammonia, which is usually toxic to aquatic animals, was also effectively removed in MPBR, with effluent concentration below 0.002mgL−1.