Fouling mitigation behavior of magnetic responsive nanocomposite membranes in a magnetic membrane bioreactor

Abstract

The aim of this study is the synthesis of a magnetic nanocomposite membrane to reduce fouling in a magnetic membrane bioreactor. To this end, Fe3O4 nanoparticles with an approximate size of 60–70 nm were settled into the polysulfone ultrafiltration membrane matrix through blending of Fe3O4 nanoparticles with the dope solution. Nanocomposite membranes containing 0–0.11 wt% Fe3O4 nanoparticles submerged in the magnetic bioreactor system in which the MLSS was considered between 8000–16,000 g/L and the magnetic field intensity was 40–160 mT. The results showed that an increase in the concentration of nanoparticles reduced the filtration resistance as much as 48% and developed the COD removal as much as 24% and increased the flux as large as 30%. The presence of a magnetic field around the bioreactor reduced the total filtration resistance as much as 68% and increased the COD removal as much as 34% due to the production of some changes in the membrane morphology and the sludge properties. Comparing the performance of the synthesized nanocomposite membranes with a MICRODYN-NADIR commercial membrane sample showed that magnetic nanocomposite membranes possess 30% higher flux, 27% lower filtration resistance, 41% higher COD removal compared to a commercial membrane. © 2016 Elsevier B.V.