A novel sponge-submerged membrane bioreactor (SSMBR) to treat a high strength wastewater for water reclamation was developed in this study. The performance of this system was evaluated using two kinds of polyester-urethane sponges (coarse sponge with higher density S28-30/45R and fine sponge with lower density S16-18/80R) with sponge volume fraction of 10% and bioreactor MLSS of 10 g/L. The results indicated the addition of sponge in SMBR could increase sustainable flux (2 times for S28-30/45R and 1.4 times for S16-18/80R) and lower TMP development, thus significantly reduce membrane fouling. S28-30/45R gave rise in attached growth biomass and the removal efficiencies of DOC, COD and PO4-P whilst S16-18/80R had better performance in removing NH4-N. Although the SSMBR performed well for most of the trials, the superior recycled water quality was achieved when adding S28-30/45R and S16-18/80R together in SMBR with the ratio of 2:1 and without any pH adjustment during the operation. (c) 2007 Elsevier Ltd. All rights reserved.