hybrid membrane reactors based on the laccase-coated nanogels could be an attractive strategy for water treatment. Ji et al. (2017) immobilized crude enzyme extracts
from Pleurotus ostreatus onto functionalized TiO 2 nanoparticles. The
nanobiocatalysts were used to treat water contaminated with two micropollutants,
namely bisphenol A and carbamazepine, in a hybrid membrane reactor. The biocatalyst gave performance comparable to the purified commercial enzyme. Crude
enzyme extracts have significant potential for cost-effective applications. Bilal
et al. (2017) prepared horseradish peroxidase cross-linked enzyme aggregates.
Biocatalytic efficiency of these aggregates was investigated for bioremediation
purposes using a newly developed packed-bed reactor system. Successful decolorization, as well as removal of different synthetic dyes, was achieved in the reactor.
After seven consecutive dye degradation cycles, 60% of the initial enzymatic activity
was retained by the aggregates. The newly developed horseradish peroxidase crosslinked enzyme aggregates have promising potential for the removal of
synthetic dyes.
Biocatalytic membranes represent a new approach for continuous treatment of
contaminated effluents. Membranes can be designed by combining various
nanostructures of the membrane with immobilized enzymes. Production of biocatalytic membranes becomes popular because of their promising application in continuous flow reactors that may be used for remediation of real wastewater. Hou et al.
(2014a) immobilized laccase on TiO 2 sol–gel coated 0.1 and 0.45 μm
polyvinylidene fluoride (PVDF) membranes. The results showed that both the pore
size of the membrane support and the number of coating cycles had a significant
impact on the biocatalytic membrane performance. The 0.1 μm thick membranes
exhibited higher activity recovery and better stability regarding bisphenol A degradation performances. Substantial improvement in bisphenol A removal efficiency
and stability were obtained under moderate flow-rate conditions, and the biodegradation process showed negligible fouling impact on the coated 0.1 μm membrane. Ji
et al. (2016a) immobilized laccase of T. versicolor onto TiO 2 nanoparticles and TiO 2
sol–gel coated PVDF membrane and tested the degradation of carbamazepine in two
different reactors. Over 65% removal of carbamazepine was achieved in the membrane hybrid reactor containing biocatalytic TiO 2 suspension within 96 h, while the
biocatalytic membrane reactor removed only 40% of carbamazepine during the same
period under identical operational conditions. The difference may be attributed to the
relatively short contact time between the attached enzymes and the substrates in the
biocatalytic membrane. In the study reported by Xu et al. (2013), a laccase enzyme
was immobilized on polyacrylonitrile nanofibrous membranes and successfully
applied for the removal of 2,4,6-trichlorophenol from water. Nanomembranes with
fiber diameters from 200 nm to 300 nm were fabricated via electrospinning and
provided a large surface area for enzyme immobilization and catalytic reactions.
Koloti et al. (2018) covalently bound laccase from Rhus vernificera on
hyperbranched polyethylenimine/polyethersulfone electrospun nanofibrous membranes. Recyclability study indicated that the laccase-modified membranes
maintained a high bisphenol A removal level, up to 79% even after four filtration
cycles. The laccase-modified membranes also maintained a constant permeate flux
360
M. Čvančarová et al.
from Pleurotus ostreatus onto functionalized TiO 2 nanoparticles. The
nanobiocatalysts were used to treat water contaminated with two micropollutants,
namely bisphenol A and carbamazepine, in a hybrid membrane reactor. The biocatalyst gave performance comparable to the purified commercial enzyme. Crude
enzyme extracts have significant potential for cost-effective applications. Bilal
et al. (2017) prepared horseradish peroxidase cross-linked enzyme aggregates.
Biocatalytic efficiency of these aggregates was investigated for bioremediation
purposes using a newly developed packed-bed reactor system. Successful decolorization, as well as removal of different synthetic dyes, was achieved in the reactor.
After seven consecutive dye degradation cycles, 60% of the initial enzymatic activity
was retained by the aggregates. The newly developed horseradish peroxidase crosslinked enzyme aggregates have promising potential for the removal of
synthetic dyes.
Biocatalytic membranes represent a new approach for continuous treatment of
contaminated effluents. Membranes can be designed by combining various
nanostructures of the membrane with immobilized enzymes. Production of biocatalytic membranes becomes popular because of their promising application in continuous flow reactors that may be used for remediation of real wastewater. Hou et al.
(2014a) immobilized laccase on TiO 2 sol–gel coated 0.1 and 0.45 μm
polyvinylidene fluoride (PVDF) membranes. The results showed that both the pore
size of the membrane support and the number of coating cycles had a significant
impact on the biocatalytic membrane performance. The 0.1 μm thick membranes
exhibited higher activity recovery and better stability regarding bisphenol A degradation performances. Substantial improvement in bisphenol A removal efficiency
and stability were obtained under moderate flow-rate conditions, and the biodegradation process showed negligible fouling impact on the coated 0.1 μm membrane. Ji
et al. (2016a) immobilized laccase of T. versicolor onto TiO 2 nanoparticles and TiO 2
sol–gel coated PVDF membrane and tested the degradation of carbamazepine in two
different reactors. Over 65% removal of carbamazepine was achieved in the membrane hybrid reactor containing biocatalytic TiO 2 suspension within 96 h, while the
biocatalytic membrane reactor removed only 40% of carbamazepine during the same
period under identical operational conditions. The difference may be attributed to the
relatively short contact time between the attached enzymes and the substrates in the
biocatalytic membrane. In the study reported by Xu et al. (2013), a laccase enzyme
was immobilized on polyacrylonitrile nanofibrous membranes and successfully
applied for the removal of 2,4,6-trichlorophenol from water. Nanomembranes with
fiber diameters from 200 nm to 300 nm were fabricated via electrospinning and
provided a large surface area for enzyme immobilization and catalytic reactions.
Koloti et al. (2018) covalently bound laccase from Rhus vernificera on
hyperbranched polyethylenimine/polyethersulfone electrospun nanofibrous membranes. Recyclability study indicated that the laccase-modified membranes
maintained a high bisphenol A removal level, up to 79% even after four filtration
cycles. The laccase-modified membranes also maintained a constant permeate flux
360
M. Čvančarová et al.