A comparative study of fouling-related properties of sludge from conventional and membrane enhanced biological phosphorus removal processes

Membrane fouling in a submerged membrane bioreactor: Impacts of floc size

“…Since the main difference of the two suspensions was that one contained some SMPs and BPCs, and the other did not, these results indicated that biopolymer matters at a level of about 0.03 g/L was much more important than 12.8 g/L suspension sludge for cake resistance in the MBR. Similar results have been also reported by other researchers [10,35,36]. The underlying causes of this phenomenon deserve further investigation.…”

Characterization of foulants in conventional and simultaneous nitrification and denitrification membrane bioreactors

“…Nitrogen removed through assimilation and SND are calculated from Eqs. (11) and (12), respectively. As shown in Table 2, the amount of nitrogen used for biomass assimilation was 4.5 and 3.7 in the conventional and SND MBRs, respectively, attesting to the 15% reduction in biomass yield achieved by the SND MBR.…”

“…Additionally, Jang et al [7] reported higher fouling rates attributed to lower EPS and consequently floc deterioration in denitrification assays. Although increased hydrophobicity was reported to enhance bioflocculation [8,9] resulting in larger more permeable flocs and reduced fouling [10], Geng and Hall [11] found no correlation between sludge relative hydrophobicity and fouling propensity in BNR systems while Le-Clech et al [12] reported higher fouling with increasing hydrophobic microbial flocs. The protein to carbohydrate ratio within the EPS was found to impact hydrophobicity and flocculating ability of the sludge more than total EPS concentration [13] and many studies reported on membrane fouling concluded that EPS composition is more important than the total quantity of EPS from the fouling perspective [5,14].…”

Impact of calcium-to-magnesium ratio on the performance of submerged membrane bioreactors

“…2). It has been well recognized that the higher SMP concentration results in the poorer filterability and more severe membrane fouling [22,23]. Based on the fact that the dosage of divalent cations was constant at 200 mg/L, the increase of SMP and decrease of BEPS with the decline of Ca:Mg ratio might be indicated that Ca 2+ was more beneficial to binding and bridging EPS compared with Mg 2+ .…”