Biodegradability, DBP Formation, and Membrane Fouling Potential of Natural Organic Matter:  Characterization and Controllability

Abstract

Various natural organic matter (NOM) constituents were evaluated in terms of their biodegradability, disinfection byproduct (DBP) formation potentials, and membrane fouling. The biodegradability of NOM was evaluated with respect to biodegradable dissolved organic carbon (BDOC) and its inhibition control. NOM was divided into (i) colloidal and noncolloidal NOM, using a dialysis membrane with a molecular weight cutoff of 3500 Da and (ii) hydrophobic, transphilic, and hydrophilic NOM constituents, using XAD-8/4 resins. The colloidal, and noncolloidal hydrophilic, NOM were identified as being more problematic than the other components, exhibiting relatively higher biodegradability and reactivity toward DBP formation potential. A higher biodegradability especially can provide a high risk of membrane biofouling, if a membrane is fouled by highly biodegradable NOM. Colloidal, and noncolloidal hydrophilic, NOM constituents were also shown as major foulants of negatively charged membranes due to their high neutral fractions. Filter adsorber (F/A) types of activated carbons were evaluated in terms of removals of NOM, DBP formation potential, and BDOC and were compared to conventional processes and a nanofiltration membrane. The F/A process exhibited a comparatively good efficiency, especially in DBP and BDOC control, but was not so good at removing NOM. This suggests that F/A could potentially be combined with a membrane process to minimize the DBP formation potential and bio-/organic-fouling (i.e., F/A process as a pretreatment for a membrane process).

A review of reverse osmosis membrane fouling and control strategies

“…One important reason is that a water layer could be easily formed on a hydrophilic surface and foulants with hydrophobic property are repellent to the surface. But it should be clarified that in certain situations hydrophilic membranes are more inclined to attract hydrophilic substances and thus induce fouling (Kwon et al, 2005). There are a number of ways to increase membrane surface smoothness as well as hydrophilic property, such as surface modifications, novel materials and synthesis process, etc.…”

Degradation characteristics of humic acid over iron oxides/Fe0 core–shell nanoparticles with UVA/H2O2

“…Disinfection byproduct formation potential during the HA degradation process was assessed according to the literature [3,23]. Various HA solutions were adjusted to pH 7 with an appropriate buffer and chlorinated (30 mg/L) using concentrated NaClO solution.…”

Parallel factor analysis of fluorescence EEM spectra to identify THM precursors in lake waters

“…It has been found that various constituents in DOM pool have different DBP formation potentials (Kitis et al 2001;Nikolaou and Lekkas 2001;Kwon et al 2005;Chow et al 2005). The knowledge of DOM profile in terms of DBP formation potential is critical to DBP control in water treatment processes.…”