Optimization of an integrated sponge – Granular activated carbon fluidized bed bioreactor as pretreatment to microfiltration in wastewater reuse

A specific integrated fluidized bed bioreactor (iFBBR) was optimized in terms of organic loading rate (OLR), hydraulic retention time (HRT) and frequency of new sustainable flocculant (NSBF) addition for primary treated sewage effluent (PTSE) treatment. It was observed that iFBBR achieved the best performance with the operating conditions of 4 times/day NSBF addition, HRT of 90 min and OLR of 8.64 kgCOD/day m3. The removal efficiencies were found to be more than 93% of dissolved organic carbon (DOC), 61% of total nitrogen (T-N) and 60% of total phosphorus (T-P). iFBBR as pretreatment of submerged microfiltration (SMF) is successful in increasing the critical flux and reducing the membrane fouling. NSBF-iFBBR-SMF hybrid system led to very high organic removal efficiency with an average DOC removal of 97% from synthetic PTSE.

► A lab-scale iFBBR incorporates an aerobic sponge bioreactor to an anoxic GAC.
► A new concept of bioadsorption and bio-flocculation was applied.
► The optimal conditions of the iFBBR were successfully determined.
► The iFBBR was an efficient pre-treatment to microfiltration.