Quantitative biofouling diagnosis in full scale nanofiltration and reverse osmosis installations

Membrane Fouling and Chemical Cleaning in Three Full-Scale Reverse Osmosis Plants Producing Demineralized Water

“…are in the low-to-medium range when compared to literature values (5-150 g cm −2 [7]). Compared to ATP literature values (4-102.000 pg cm −2 ) [7,[25][26][27], all values measured in this study were low. Location II, which had the highest ATP in this study, also had the highest measured polysaccharides concentration and CFU plate counts ( Figure 5).…”

The role of cell-surface interactions in bacterial initial adhesion and consequent biofilm formation on nanofiltration/reverse osmosis membranes

“…Furthermore, in most cases, membrane fouling by natural organic matter, polysaccharides and inorganic material will occur, which can change substantially the membrane surface properties such as hydrophobicity [107], roughness [108] and surface charge [109]. Several membrane autopsies carried out on NF and RO membranes have showed the fouling layer to be composed of different materials [110][111][112][113], caused by the different water quality treated. The characteristics of the fouling layer can therefore be expected to influence the nature of subsequent bacterial adhesion and possibly biofilm formation.…”

“…They consisted mostly of live bacterial cells. Semião et al [115] showed that a conditioning cake layer deposited on the NF membrane surface due to [4,110,111], and hence linked to the fouling layer that forms on the membranes surface. Moreover, if this fouling layer forms at a higher rate than bacterial adhesion and biofilm formation, it is critically important to assess the methodologies for quantifying the performance of novel antibiofouling membranes in the context of full scale operation as opposed to laboratory testing.…”

Bacterial adhesion onto nanofiltration and reverse osmosis membranes: Effect of permeate flux

“…NF is principally used for the removal of hardness, trace contaminants, such as pesticides and organic matter (Cyna et al (2002)), while RO is used for desalination (Greenlee et al (2009)). NF and RO performance are however adversely affected by biofilm formation resulting in permeate flux and quality decline (Flemming (1997), Houari et al (2009), Ivnitsky et al (2007), Khan et al (2013), Vrouwenvelder et al (1998), Vrouwenvelder et al (2008)), generally caused by the initial adhesion and subsequent colonization of bacterial cells on the surface of the membrane, amalgamating in a biomass consisting of, and not limited to, polysaccharides, proteins, and extracellular DNA (Pamp et al (2007)). …”