Biocatalytic System Made of 3D Chitin, Silica Nanopowder and Horseradish Peroxidase for the Removal of 17α-Ethinylestradiol: Determination of Process Efficiency and Degradation Mechanism

Abstract

The occurrence of 17α-ethinylestradiol (EE2) in the environment and its removal have drawn special attention from the scientific community in recent years, due to its hazardous effects on human and wildlife around the world. Therefore, the aim of this study was to produce an efficient enzymatic system for the removal of EE2 from aqueous solutions. For the first time, commercial silica nanopowder and 3D fibrous chitinous scaffolds from Aplysina fistularis marine sponge were used as supports for horseradish peroxidase (HRP) immobilization. The effect of several process parameters onto the removal mechanism of EE2 by enzymatic conversion and adsorption of EE2 were investigated here, including system type, pH, temperature and concentrations of H2O2 and EE2. It was possible to fully remove EE2 from aqueous solutions using system SiO2(HRP)–chitin(HRP) over a wide investigated pH range (5–9) and temperature ranges (4–45 °C). Moreover, the most suitable process conditions have been determined at pH 7, temperature 25 °C and H2O2 and EE2 concentrations equaling 2 mM and 1 mg/L, respectively. As determined, it was possible to reuse the nanoSiO2(HRP)–chitin(HRP) system to obtain even 55% EE2 degradation efficiency after five consecutive catalytic cycles.

Inorganic Oxide Systems as Platforms for Synergistic Adsorption and Enzymatic Conversion of Estrogens from Aqueous Solutions: Mechanism, Stability and Toxicity Studies

“…Decrease of removal efficiency with increasing EE2 concentration may be related to the limited number of active sites on the surface of the support capable for EE2 sorption, due to the presence of immobilized (active) and inactivated laccase as well as due too high amount of EE2 molecules in the solution [14]. A similar study was made by Machałowski et al, [38], who used EE2 solutions at concentrations of 1 and 5 mg/L and investigated its removal using horseradish peroxidase immobilized onto nanoSiO 2 and chitin. Synergistic removal of estrogen by enzymatic conversion and adsorption onto applied supports was observed, however in that study the similar amount of EE2 was adsorbed onto proposed materials, regardless of the initial concentration used.…”

Nanochitin for sustainable and advanced manufacturing

“…To date, numerous biocatalysts have been reported, including lipase, 153,154 glucose oxidase mainly for biosensors, 155 and horseradish peroxidase. 156 The choice of immobilization method depends on the specific enzyme, choice of supporting materials and the intended application. Examples of the explored immobilization methods include physical adsorption, ionic binding and covalent binding.…”

Biomass-derived functional materials as carriers for enzymes: towards sustainable and robust biocatalysts

“…The enzymes bound to the chitin matrix also have greater thermal activity than that of free enzymes. Table 4 130–150 displays examples of recent research that used chitin-based supports to enhance the stability and activity of enzymes.…”