Analysing the effect of Quinalphos pesticide on fish health through molecular docking studies and their eradication by photocatalytic degradation using Fe/S/TiO۲ nanocomposite

In view of growing environmental issues there is a requirement for the immediate eradication of pesticides and its residues from local and commercial streamlets. Quinalphos is one of the most common organophosphorous pesticide especially used in agricultural fields bring about a great impact in environment thereby affecting the health of aquatic organisms and humans. Among the various type of method that has been implemented, photocatalytic reaction is considered as the most relevant technique for the removal of toxic organic contaminants. In this study, modified TiO۲ has been synthesized by doping with Fe, S using a simple one-step sol-gel method. The incorporation of Fe۳+ and the distribution of S nonmetal in TiO۲ crystal lattice were affirmed by the XRD, SEM and FT-IR analysis. The band gap energy of Fe/S/TiO۲ nanocomposite has been narrowed to ۲.۵eV and its photocatalytic activity was extended to the visible region. Thus Fe/S/TiO۲ photocatalyst was employed for the eradication of Quinalphos and the complete mineralization was achieved in ۱۲ min of visible light irradiation and it is analyzed by TOC analysis. Furthermore, the reusable feature of the catalyst was demonstrated to be utilised for twelve cycles. The penetration of pesticide residues on protein pockets of fishes was predicted by molecular docking. Furthermore, the reduction in toxicity level of the effluent was examined by using aquatic organisms. Thus Fe/S/TiO۲ nanocomposite is an efficient photocatalyst to oxidize emerging organic contaminants due to its high synergetic effect of visible light absorbing tendency and low recombination effect of charge carriers.

Keywords:

Quinalphos pesticide , Fish protein , Molecular Docking , Fe/S/TiO۲ nanocomposite , Mineralisation