Removal of anthracene from model wastewater by immobilized peroxidase from Momordica charantia in batch process as well as in a continuous spiral-bed reactor

The aim of this study was to develop a system based on the use of immobilized peroxidase from bitter gourd (Momordica charantia) for the removal of polycyclic aromatic hydrocarbon, anthracene. In vitro removal of anthracene by soluble and calcium alginate–starch beads surface immobilized peroxidase was investigated in the presence of a redox mediator, guaiacol. The maximum oxidation of anthracene was observed in the presence of 0.70 mM H2O2 and 0.4 U mL−1 of the enzyme in sodium acetate buffer, pH 4.0 at 40 °C in 2.5 h. The oxidative degradation and polymerization of anthracene was increased more than two-fold in the presence of 0.1 mM guaiacol. The oxidation of anthracene was quite effective in batch process, 99% anthracene was removed in 7 h by immobilized enzyme. The spiral-bed reactor filled with immobilized enzyme retained more than 40% anthracene removal efficiency even after 1 month of its continuous operation. The absorption spectra of anthracene after treatment exhibited a marked difference in absorbance at respective wavelengths as compared to untreated compound. FT-IR analysis has shown a derivative of anthraquinone as a product of peroxidase catalyzed anthracene conversion. Allium cepa toxicity assay showed that the peroxidase catalyzed product of anthracene was less toxic as compared to parent compound.

Bitter gourd (Momordica charantia) peroxidase immobilized on the surface of concanavalin A layered calcium alginate–starch hybrid beads has been employed for the removal of anthracene from the model wastewater. Immobilized bitter gourd peroxidase was successfully used for the removal of anthracene, a PAH model compound, from the polluted water containing water-miscible organic solvents. The oxidation and removal of anthracene was optimized under various experimental conditions. A large scale treatment of anthracene by immobilized enzyme has been investigated in a batch process as well as in a continuous spiral-bed reactor. The degradation pathway of anthracene by bitter gourd peroxidase was illustrated as given below.Figure optionsDownload as PowerPoint slideResearch highlights▶ In this manuscript a polyaromatic hydrocarbon, anthracene was transformed into a nontoxic product by BGP in the presence of water miscible organic solvents. ▶ Various experimental parameters such as effect of redox mediators, enzyme concentration, pH and temperature were performed for the maximum removal of this compound. Alliam cepa toxicity assay was also performed to determine the toxicity of parent as well as the product. FT-IR spectra of BGP catalyzed product of anthracene shown a clear evidence of the formation of 9,10-anthraquinone. ▶ In last batch process and spiral bed-reactor were also performed at industrial scale. The degradation pathway of anthracene by BGP was also determined.