Enhanced dephenolization using sequential biological and photocatalytic treatment

Novel eco-preserving system was developed by combining biological and photocatalytic treatment techniques for synergistic removal of phenol from aqueous media. Penicillium chrysogenum a filamentous fungus was able to remove 77.3 % out of 125 mg/l phenol within 168 h. On the other hand, ZnO nanoparticles that were developed within low density polyethylene(LDPE)-g-(styrene(Sty)-co-acrylic acid(AAc)) sheets, prepared by γ-radiation induced graft copolymerization, were able to remove 77.6 % out of 125 mg/l phenol within 24 h. Combining both techniques via the employment of the developed LDPE-g-(Sty-co-AAc)/ZnO nanocomposite for 6 h prior to 18 h of biological treatment resulted in the removal of 89.5 % out of 125 mg/l phenol. The degradation products were assayed using fourier transform infrared spectroscopy (FT-IR), while enzyme assay was performed to propose a pathway for degradation. A phytotoxicity test showed that the synergistic degradation products were less toxic than phenol. Moreover, LPDE-g-(Sty-co-AAc)/ZnO nanocomposite sheets were used three times with the same efficiency. The aforementioned results recommend biological/photocatalytic combined treatment technique as a promising eco-preserving system that reduce the potential toxicity of the treated waste water that offer a bonus of practicality and cost-effectiveness.