An innovative technology for treating municipal and industrial wastewater with low sludge production

The paper reports the results of an experimental investigation aimed at transferring to demonstrative scale an innovative technology (SBBGR - Sequencing Batch Biofilter Granular Reactor) for the treatment of municipal and industrial wastewater by financial support of the EU Life programme. When this technology was applied for treating municipal wastewater, the results showed that the system was able to remove 80-90% of COD, total suspended solids and ammonia independently of the hydraulic residence time investigated (i.e., from 12 to 4 h). The process was characterised by a very high sludge age value (?c?150 d) that led to a biomass concentration as high as 35 gTSS/Lbed and a sludge production much lower (6-7 times lower) that than commonly reported for conventional treatment plants. In the case of tannery wastewater, chosen as representative of industrial wastewater, SBBGR technology was suitable for removing 80-90% of the COD, suspended solids and ammonia content up to organic loading values of 3?3.5 kg COD/m3?d.