Interactions of Organophosphate Pesticides with Essential Metal ions and its Environmental Impacts

Abstract

I newlineABSTRACT newlineThis thesis addresses Interactions of Organophosphate Pesticides with Essential Metal ions and it s Environmental Impacts of four pesticides (acephate, glyphosate, monocrotophos and phorate). Within the scope of the thesis, following five points are the highlights of thesis: newline1) Interactions, mode of bonding and stability (chemical and thermal) of four organophosphate pesticides with metal ions (Mn, Fe, Co, Ni, Cu and Zn) at neutral pH. newline2) Affect of soil components (mainly humic acid) on interactions, mode of bonding and stability (chemical and thermal) of four organophosphate pesticides with metal ions (Mn, Fe, Co, Ni, Cu and Zn) at neutral pH. newline3) Affect of four organophosphate pesticides on siderophore production ability of plant growth promoting rhizobacterial strains. newline4) Affect of four organophosphate pesticides on wheat growth and metal content of seeds of wheat. newline5) Affect of four organophosphate pesticides under cocktailed effect (mixture of two pesticides at a time). Draft newlineIn the whole thesis, following points are the main outcomes newlineIt was observed that in the presence of soil components (mainly humic acid), the rate of interactions of four pesticides with metal ions was similar to that of without humic acid or pesticide to metal ion only, except first few hours interactive study. The observed rate of interactions was slow in the presence of humic acid, may be because of steric hindrance of bulky molecule humic acid. newlineBased on UV-visible analysis, the order of complexation of four pesticides with different metal ions in the presence/ absence of humic acid was; Zn(II) lt Cu(II) gt Ni(II) gt Co(II) gt Fe(II) gt Mn(II). newlineII newlineFTIR, NMR, mass and TGA study have proved that pesticides under study can form the stable complexes with metal ions through the P=X (X = O or S), S, C=O and NH, and form the kinetically and thermally stable five/ six membered rings. newlineIn the presence of humic acid, these pesticides can form complexes through the axial bonds in ratio 2:1:2 of humic acid: metal ion: pesticide. newlineUV-visible (