Laccase-immobilized dendritic nanofibrous membranes as a novel approach towards the removal of bisphenol A

Abstract

Laccase enzymes from Rhus vernificera were covalently bound on hyperbranched polyethyleneimine/polyethersulfone (HPEI/PES) electrospun nanofibrous membranes and used for the removal of bisphenol A (BPA) from water. The laccase enzyme was anchored on the dendritic membranes through the abundant peripheral amine groups on the HPEI using glutaraldehyde as a crosslinker. The membranes were characterized with attenuated total reflectance-Fourier transform infrared spectroscopy, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) and ultraviolet-visible spectroscopy and correlative light and electron microscopy (CLEM). Furthermore, contact-angle analyses, pure water flux measurements and rejection analyses were carried out. CLEM showed that the enzymes were uniformly dispersed on the nanofibres while SEM analysis revealed that the nanofibres had an average diameter of 354 ± 37 nm. EDS showed the presence of Cu, which is the active entity in laccase enzymes. The laccase-modified membranes were hydrophilic (50°-53° contact angle) and exhibited high BPA rejection of 89.6% as compared to the 52.4% demonstrated by pristine PES. The laccase-modified membranes also maintained a constant permeate flux (7.07 ± 5.54 L/m h) throughout the filtration process. Recyclability studies indicated that the membranes still maintained a high BPA removal of up to 79% even after four filtration cycles.

Optimization and efficacy studies of Laccase immobilized on Zein-Polyvinyl pyrrolidone nano fibrous membrane in decolorization of Acid Red 1

“…In another report, leaching of immobilized carbonic anhydrase from polylactic acid nanofibrous membranes modified by graphene oxide was found to be less due to steady covalent bonds formed between the enzyme and the support (Sahoo et al 2015). Recyclability studies of laccase immobilized in dendritic nanofibrous membranes for the removal of Bisphenol A by Koloti et al pointed out a removal efficiency of up to 79% even after four filtration cycles (Koloti et al 2017).…”

Investigation of Biocidal Effect of Microfiltration Membranes Impregnated with Silver Nanoparticles by Sputtering Technique

“…The PES membrane contains sulfone and ether groups alternated between aromatic rings [ 44 , 49 ]. The FTIR spectra show characteristic bands of PES: (1) 3094 and 3062 cm −1 due to aromatic C–H stretch ( Figure S1B ) [ 46 , 49 , 50 ]; (2) 1574 and 1481 cm −1 due to aromatic C=C asymmetric stretch ( Figure S1C ) [ 44 , 50 ]; and (3) 1320 and 1296 cm −1 resulting from the anti-symmetric O=S=O stretch of the sulfone group ( Figure S1D ) [ 44 , 49 , 50 ]. Moreover, the FTIR spectra shows the presence of PVP with a characteristic band at 1650 cm −1 due to carbonyl group ( Figure S1E ) [ 46 , 47 , 50 ].…”

Photocatalytic degradation of a basic dye in water by nanostructured HPEI/TiO2 containing membranes

“…HPEI was used as a template and dispersing agent for the synthesis of TiO 2 nanoparticles. HPEI has cavities that act as hosts for nanoparticle synthesis through electrostatic attractions between the nitrogen groups, thus producing uniform and well-dispersed nanoparticles (Koloti et al, 2018;Mathumba et al, 2017). In our previous study HPEI played a significant role in the production of small and well-dispersed TiO 2 nanoparticles (Mathumba et al, 2017).…”