A PVC-silica mixed-matrix membrane (MMM) as novel type of membrane bioreactor (MBR) membrane

A highly porous mixed matrix membrane (MMM), made from polyvinyl chloride (PVC) and silica, commonly used as separator in lead acid batteries, is screened here in a first feasibility study as a potential novel type of MBR membrane to treat synthetic wastewater encouraged by: (i) its high chemical and thermal stability and (ii) its high porosity. Its performance was compared with two commercial flat-sheet MBR membranes, a chlorinated PE and a PVDF membrane, in terms of hydraulic performance and membrane fouling. The COD removals of the three membranes were similar. The critical flux measurement also showed the potential of the MMM, being 18 LMH compared to 21 LMH for the commercial membranes. However, both short and long-term filtration tests showed that the MMM suffers from a severe irreversible fouling attributed to the blocking of the large pore mouths, which could not be removed via the applied chemical cleaning with NaOCl. Nevertheless, in a long-term test, despite the occurrence of pore blocking, other types of fouling exist to a much lesser extent in the MMM which maintains its performance comparable with the two commercial membranes.