Surface modification of membrane bioreactor by hybrid halloysite nanotubes for industrial wastewater treatment containing heavy metals

Surface modification of polysulfone (PSF) membrane bioreactor using hybrid halloysite nanotubes (HHNTs) and dendrimers was investigated for industrial wastewater treatment containing heavy metals. Petroleum wastewater was obtained from liquefied gas plant 1200 (NGL 1200) in Gachsaran, Iran. Polysulfone)PSF( membranes were fabricated using hybrid halloysite nanotubes and dendrimers at different concentrations of 0, 0.5, 1, and 2 wt% and identified with certain codes of PSF, HNT0.5, HNT1, and HNT2, respectively. The fabricated membranes were characterized by FTIR, AFM, EDX, SEM, and contact angle analyses. The contact angle decreased as a result of HNT loading in PSF membranes, which was due to the enhancement of the membrane hydrophobicity. The heavy metal rejection in the HNT1 membrane for Cu (II), Pb (II), Ni (II), and Zn (II) was 83.25%, 98.79%, 81.09%, and 85.98%, respectively. Also, the rejection of Ni (II) in PSF was 38.24% which showed a lower amount. Based on the results, the HNT1 membrane which was fabricated using 1 wt% of the hybrid halloysite nanotubes showed the best performance to heavy metals removal from industrial effluents.

Graphical abstract