Nanofiltration fouling propensity caused by wastewater effluent organic matters and surface-water dissolved organic matters

Abstract

Rejection of dissolved organic matters (DOMs) from wastewater treatment plant effluent (EfOM) and surface reservoir water (RW-DOM) by nanofiltration (NF) was comparatively studied to evaluate their influence on membrane fouling and to unveil the major causations. EfOM and RW-DOM were fractionated to determine the major components that preferentially form fouling layer and initiate biofouling. The results indicated that EfOM induced a rapid membrane permeability loss and a more complicated biofilm diversity than RW-DOM did. Hydrophilic components with small molecular weight (<3 kDa), and SMP in EfOM made a crucial contribution to membrane flux decline, while the hydrophobic large-molecular-weight components (>50 kDa) resulted in initially quick membrane fouling. The complex biofouling resulted from EfOM closely related with significant retention of SMP on the non-porous NF membrane surface, where the Proteobacteria phylum dominated the biofouling formed by microbial community growth and accumulation that gave rise to serious irreversible membrane fouling.

The Best-Practice Organism for Single-Species Studies of Antimicrobial Efficacy against Biofilms Is Pseudomonas aeruginosa

“…The top three most frequent classes of organisms were in Proteobacteria , including, Alphaproteobacteria , followed by Gammaproteobacteria and Betaproteobacteria . These results were supported by results found in [ 21 , 44 , 77 , 79 , 80 ]. For example, in Hörsch et al [ 81 ], researchers found Alphaproteobacteria to be the most abundant class of organisms on RO membranes, followed by Gammaproteobacteria .…”

“…This semi-systematic review for question 2 determined thirty-three phyla of organisms corresponding to forty-four classes of organisms that were identified in various studies via 16S rRNA analysis in biofouling samples from RO systems. Similar to results from question 1, the most common organisms identified were in the phylum Proteobacteria [ 21 , 44 , 79 ]. The top three most frequent classes of organisms were in Proteobacteria , including, Alphaproteobacteria , followed by Gammaproteobacteria and Betaproteobacteria .…”

“…For question 2, we found that the most common organisms in biofilms on RO membranes were from the phylum Proteobacteria . Shang et al [ 79 ] concluded that the phyla Proteobacteria contained the main pioneer organism of marine biofilms on RO membranes, which was also supported by results from Ma et al [ 98 ] and Hu et al [ 99 ]. As stated earlier, Hörsch et al [ 81 ] found Gammaproteobacteria to be the first colonizers of the membrane.…”

“…EPS is integral for conditioning of the membrane for initial attachment and for the development of mature biofilms. According to Shang et al [ 79 ], organisms in Proteobacteria produced more EPS than other bacterial phyla. For example, Ivnitsky et al [ 81 ] identified that Gammaproteobacteria had superior attachment ability compared to other organisms due to the production of EPS, making it a common pioneer organism.…”

Removal of Hardness in Wastewater Effluent Using Membrane Filtration

“…Otherwise, it is non-reversible. In [20,21] it was documented that in the case of the nanofiltration of effluents from urban wastewater treatment plant fouling is usually reversible.…”