Immobilized horseradish peroxidase on boric acid modified polyoxometalate molecularly imprinted polymer for biocatalytic degradation of phenol in wastewater: Optimized immobilization, degradation and toxicity assessment.

The degradation of phenol from wastewater is crucial for environmental protection. Biological enzymes, such as horseradish peroxidase (HRP), have shown great potential in the degradation of phenol. In this research, we prepared a hollow CuO/Cu 2 O octahedron adsorbent with a carambola matrix shape through the hydrothermal method. The surface of the adsorbent was modified by silane emulsion self-assembly, where 3-aminophenyl boric acid (APBA) and polyoxometalate (PW 9) were combined with silanization reagents and grafted onto the surface. The adsorbent was then molecularly imprinted with dopamine to obtain boric acid modified polyoxometalate molecularly imprinted polymer (Cu@B@PW 9 @MIPs). This adsorbent was used to immobilize HRP, which served as a biological enzyme catalyst from horseradish. The adsorbent was characterized, and its synthetic conditions, experimental conditions, selectivity, reproducibility, and reusability were evaluated. The maximum adsorption amount of HRP under optimized conditions was 159.1 mg g−1, as determined using high-performance liquid chromatography (HPLC). At pH 7.0, the immobilized enzyme showed a high efficiency of up to 90.0% in removing phenol, after 20 min of reaction with 25 mmol L−1 H 2 O 2 and 0.20 mg mL−1 Cu@B@PW 9 @HRP. Growth tests of aquatic plants confirmed that the adsorbent reduced harm. Gas chromatography-mass spectrometry (GC-MS) tests revealed that the degraded phenol solution contained about fifteen phenol derivatives intermediates. This adsorbent has the potential to become a promising biological enzyme catalyst for dephenolization. The horseradish peroxidase was immobilized on the boric acid modified polyoxometalate molecularly imprinted polymer to establish a biocatalytic enzyme system. A catalytic oxidation system was constructed using hydrogen peroxide, providing a new method for removing phenol from wastewater (Cu@B: Boric acid modified CuO/Cu 2 O; PW 9 : polyoxometalate; HRP: Horseradish peroxidase; Cu@B@PW 9 : Boric acid and polyoxometalate modified CuO/Cu 2 O; Cu@B@PW 9 @MIPs: boric acid modified polyoxometalate molecularly imprinted polymer). [Display omitted] • A novel boric acid modified polyoxometalate molecularly imprinted polymer have been successfully prepared. • Adsorbent can immobilize horseradish peroxidase (HRP) from plant horseradish. • Measured using high performance liquid chromatography (HPLC), the adsorbent have excellent kinetic properties. • The method has a good removal effect on phenol, which can effectively reduce toxicity. [ABSTRACT FROM AUTHOR]