Nanofiltration of natural organic matter with H2O2/UV pretreatment: fouling mitigation and membrane surface characterization

A comprehensive study into fouling properties of extracellular polymeric substance (EPS) extracted from bulk sludge and cake sludge in a mesophilic anaerobic membrane bioreactor

“…The peaks of 1550 cm À1 and 1400 cm À1 may demonstrate the presence of fatty acid on the membrane. The spectral bands at wave numbers 1070 cm À1 was based on the C-O-C vibrations, exhibited the character of polysaccharides or polysaccharides-like substances (Song et al, 2004). It was evident from above observations that proteins, polysaccharides, and fatty acids were presented in the fouling layers of EPS fractions extracted from bulk sludge and cake sludge.…”

Drinking Water: Factors Affecting the Quality of Drinking Water

“…By means of micro-and ultrafiltration large NOC fractions are not always removed from water. To raise the efficiency of membrane separation, as is shown in paper [252,253] it is expedient to use oxidation of impurities with ozone or H 2 O 2 /UV before nanofiltration. Oxidation of H 2 O 2 /UV may lead to complete destruction of synthetic organic matter and transformation of humic or hydrophobic substances into nonionic or less hydrophobic compounds.…”

“…In addition, quinone groups do not form hydrogen bonds with the peptide skeleton of other NOC molecules, which prevents the formation of NOC polymolecular layers on the membrane surface in adsorption [253]. Thus, the technological mode of preliminary oxidation of water impurities before membrane filtration in the case of shallow oxidation should maximally ensure the transformation of phenol groups into quinone ones.…”

“…The given method is sufficiently practical, effective from the economic point of view and makes it possible to recover membrane properties. However, in paper [253] the preference is given to alkaline washing due to the following reasons. Cleaning with the alkaline solution is advisable in the case of the high content of humic and fulvic acids, which are well soluble in alkaline solutions.…”

The use of integrated countercurrent nanofiltration cascades for advanced separations

“…11,12 Secondly, the membrane performance can decrease due to fouling. 2,13,14 Thirdly, high-mass-transfer-flux, defect-free, stable, long-lifetime membranes are needed on a large scale, fabricated into compact, economic modules of high surface area per unit volume. 15 Finally, the desired permeate and/or retentate stream quality has to be achieved; in other words, a good separation between components has to be attained.…”