Laccase Immobilized onto Zirconia–Silica Hybrid Doped with Cu2+ as an Effective Biocatalytic System for Decolorization of Dyes

Abstract

Nowadays, novel and advanced methods are being sought to efficiently remove dyes from wastewaters. These compounds, which mainly originate from the textile industry, may adversely affect the aquatic environment as well as living organisms. Thus, in presented study, the synthesized ZrO2–SiO2 and Cu2+-doped ZrO2–SiO2 oxide materials were used for the first time as supports for laccase immobilization, which was carried out for 1 h, at pH 5 and 25 °C. The materials were thoroughly characterized before and after laccase immobilization with respect to electrokinetic stability, parameters of the porous structure, morphology and type of surface functional groups. Additionally, the immobilization yields were defined, which reached 86% and 94% for ZrO2–SiO2–laccase and ZrO2–SiO2/Cu2+–laccase, respectively. Furthermore, the obtained biocatalytic systems were used for enzymatic decolorization of the Remazol Brilliant Blue R (RBBR) dye from model aqueous solutions, under various reaction conditions (time, temperature, pH). The best conditions of the decolorization process (24 h, 30 °C and pH = 4) allowed to achieve the highest decolorization efficiencies of 98% and 90% for ZrO2–SiO2–laccase and ZrO2–SiO2/Cu2+–laccase, respectively. Finally, it was established that the mortality of Artemia salina in solutions after enzymatic decolorization was lower by approx. 20% and 30% for ZrO2–SiO2–laccase and ZrO2–SiO2/Cu2+–laccase, respectively, as compared to the solution before enzymatic treatment, which indicated lower toxicity of the solution. Thus, it should be clearly stated that doping of the oxide support with copper ions positively affects enzyme stability, activity and, in consequence, the removal efficiency of the RBBR dye.

Congo Red Decolorization Using Textile Filters and Laccase-Based Nanocomposites in Continuous Flow Bioreactors

“…In this study, the improved behavior was attributed to the hydrophobic/hydrophilic interaction of the nanoparticles [ 57 ]. Similar studies demonstrated dye removal efficiencies in the range of 30% to 100% [ 25 , 26 , 59 ]. However, such levels of removal have been mainly achieved on batch processes with longer removal times than ours (i.e., in the scale of hours).…”

“…Some of the preferred materials for immobilization include macroscopic materials, such as metal oxides, natural polymers, and some minerals, as well as nanomaterials, such as magnetite, gold, and silica [ 11 , 21 , 23 , 24 ]. Other recent reports have demonstrated that by immobilizing laccases, the rate of dye degradation increases considerably [ 25 , 26 ]. For instance, the immobilization of laccase on materials, such as Zirconia-Silica Hybrid Doped with Cu +2 , is an attractive route for decolorization of the Remazol Brilliant Blue R dye [ 25 ].…”

“…Other recent reports have demonstrated that by immobilizing laccases, the rate of dye degradation increases considerably [ 25 , 26 ]. For instance, the immobilization of laccase on materials, such as Zirconia-Silica Hybrid Doped with Cu +2 , is an attractive route for decolorization of the Remazol Brilliant Blue R dye [ 25 ]. This was also the case after immobilization of laccase on electrospun fibers of poly(methyl methacrylate)/polyaniline [ 26 ].…”

α-Cellulose Fibers of Paper-Waste Origin Surface-Modified with Fe3O4 and Thiolated-Chitosan for Efficacious Immobilization of Laccase

“…Hence, the detailed activity recovery and laccase loading capacity data provided the information about immobilization behavior of α-Cellulose-Fe3O4-CTNs-SH. The significant laccase loading obtained by α-Cellulose-Fe3O4-CTNs-SH was quite high among the recently reported materials [33,46,[54][55][56][57][58][59][60][61]. Thus, the developed α-cellulose based material has significant potential to look like an enzyme immobilization material.…”

Alcalase Microarray Base on Metal Ion Modified Hollow Mesoporous Silica Spheres as a Sustainable and Efficient Catalysis Platform for Proteolysis

“…In addition to proper immobilization method, suitable supports for targeted enzyme was also essential for immobilization (Dong et al, 2019b;Jankowska et al, 2019). In order to gain higher enzyme loading capacity and biocatalytic activity, it is always highly desirable to invent novel supports with high-performance (Antecka et al, 2018;Elizarova and Luckham, 2018;Zdarta et al, 2019;Jankowska et al, 2020).…”