Deliverable D. 2.3 ("Midterm report on sludge minimization by different techniques") of ROUTES Project ("Novel processing routes for effective sewage sludge management"

The ROUTES project is addressed to study new innovative solutions based on different approaches for minimizing sludge production in wastewater treatment. This report shows the preliminary results obtained by applying two different solutions proposed by IRSA, i.e. the Sequential Batch Biofilter Granular Reactor (SBBGR) based technology and Membrane Bio Reactors (MBR) with integrated sidestream process on the sludge recycle. This report is structures as follows. After the preface, Chapter 1 is addressed to SBBGR technology. In particular, after SBBGR technology introduction, the description of the experimental set-up used and operating programme is reported. The chapter ends with the results obtained during the first year of lab-scale plant operation, and preliminary evaluation of the effectiveness of the SBBGR on minimization of sludge production and organic load removal. Chapter 2 is dedicated to Membrane Bio Reactors (MBR) with integrated side-stream process solution. An introduction about the different mechanisms for sludge reduction in biological processes is followed by a literature review about the potentials and drawbacks of ozonation, sonication and anaerobic reactors in light of their application with MBRs. The anaerobic side-stream process was selected for experimental investigation and the results of the first eight months of tests on two lab-scale systems are reported. The effect of key operational parameters have been assessed and optimal operational conditions identified.