Membrane bioreactors troubleshooting through the preparation of a high antifouling PVDF ultrafiltration mixed-matrix membrane blended with O-carboxymethyl chitosan-Fe3O4 nanoparticles.
Environ Technol
; 40(26): 3523-3533, 2019 Nov.
Article
in En
| MEDLINE
| ID: mdl-29799366
ABSTRACT
Polymeric ultrafiltration (UF) membranes often used in membrane bioreactor (MBR) prone to be fouled by fouling agents. Therefore, in this paper, the antifouling characteristics of polyvinylidene fluoride (PVDF) UF membranes for wastewater treatment are improved through modifying membranes by O-carboxymethyl chitosan (OCMCS)-functionalized Fe3O4 nanoparticles (OCMCSFe3O4). The modifier agent was manufactured by the adsorption of OCMCS on Fe3O4 nanoparticles, which were synthesized via co-precipitating method. Antifouling performance of membranes was assessed by permeation tests done using activated sludge suspension as a biological foulant, then the calculation of the pure water flux recovery ratio (FRR) and fouling resistance parameters. Also, to investigate the protein rejection of membranes, permeation tests were conducted by the bovine serum albumin (BSA) solution. According to the obtained results, surface hydrophilicity of the embedded membranes was improved in the low concentrations of the modified nanoparticles. However, the high quantity of the OCMCS-Fe3O4 nanoparticles (>0.1â
wt. %) in the casting solution lessened membrane performance owing to the agglomeration of the nanoparticles in the polymer matrix. Although, the 1â
wt. % OCMCS-Fe3O4 membrane revealed considerably higher PWF and permeation than that of the other membranes. It was because of defects and cracks in the membranes. The 0.05 wt. % OCMCS-Fe3O4/PVDF membrane exhibited the highest FRR (95.7%) and protein rejection value (48%) and the lowest irreversible fouling resistance (Rir) value (4.2%). It is concluded that the blended membranes with modified nanoparticles resulted in a high-flux ultrafiltration membrane comparable with microfiltration membrane, while its separation properties remained similar to UF membrane.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ultrafiltration
/
Nanoparticles
Language:
En
Journal:
Environ Technol
Journal subject:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Year:
2019
Document type:
Article
Affiliation country:
Iran
Country of publication:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM