Combining submerged membrane technology with anaerobic and ...

TMP (kPa)TMP (kPa)TMP (kPa)TMP (kPa)TMP (kPa)TMP (kPa)Chapter 33.4.2.2. Influence of nitrification on membrane performanceIn addition to the presence of suspended solids in the fed wastewater, nitrificationalso affected TMF. The performance of both membranes was better when nitrification didnot occur than when full ammonia oxidation took place (approximately 30 mgN-NO x·L -1 )(figures 3.10.1 and 3.10.3, respectively), although no significant differences were observeddepending on biomass aggregation state. However, when ammonia was partially oxidised(approximately 10 mgN-NOx·L -1 ) in the TMF chambers, the membrane in the granularsystem performed better than the one in the flocculent system, reaching 50% lowerpressures when operated at the critical flux (figure 3.10.2). The effects of ammonianitrification variations on membrane behaviour have been previously reported forsecondary MBR systems (Drews et al., 2007).50401a50401b30201000 10 20 30 40 50 60 70 80 90Time (min)50402a30201000 10 20 30 40 50 60 70 80 90Time (min)50402b30201000 10 20 30 40 50 60 70 80 90Time (min)50403a30201000 10 20 30 40 50 60 70 80 90Time (min)50403b3030201000 10 20 30 40 50 60 70 80 90Time (min)201000 10 20 30 40 50 60 70 80 90Time (min)Figure 3.10. Critical flux test for flocculent (a) and granular (b) systems in conditions of nonitrification (1), moderate nitrification (2) and full nitrification (3). () 8.9 L·m -2·h -1 , () 14.5L·m -2·h -1 , () 19.0 L·m -2·h -1 , (•) 24.5 L·m -2·h -1 , () 30.1 L·m -2·h -1 and (‣) 34.6 L·m -2·h -1 .These tests were carried out with biomass concentrations between 1 and 2 g·L -1 inboth of TMF chambers. It was reported (Judd, 2004) that at low biomass concentrations,100