Mechanically stirred enzymatic membrane reactor containing HRP immobilized on Tau-SiO2@Fe3O4-GO nanocomposite for removal of tetracycline in synthetically concocted wastewater

Abstract

The process of mechanically stirred membrane reactor containing the suspension of horseradish peroxidase (HRP) immobilized on synthesized nanocomposite (Tau-SiO₂@Fe₃O₄-GO) was designed for continuous degradation of tetracycline. The immobilized HRP was characterized in terms of kinetic parameters and catalytic activities as these parameters were improved highly through immobilization. The stability indices including pH and temperature were investigated in parallel. The immobilized HRP was more tolerable to pH changes as compared to free HRP and the optimum temperature obtained at 40 °C. The reusability of HRP was promoted by immobilization as far as 70% of initial activity after ten cycles. The enzymatic degradation of optimum concentration of tetracycline was carried out in batch condition and 100% of tetracycline removed after 30 min. The results also showed that higher concentration of H₂O₂ exhibited more oxidation of tetracycline. The optimal ratio of HRP/H₂O₂ was also obtained at 0.005. The simultaneous process including separation and the biocatalytic degradation established in the membrane stirrer reactor concluded that no amount of tetracycline was observed in the permeate stream coming from the membrane after 30 min of operation.

Graphical abstract