BEHAVIOUR CERTAIN PESTICIDE RESIDUES IN WATER AND SOIL

Abstract

The fate and behaviour of the organosulfur fungicide isoprothiolane (diisopropyll , 3- dithiolane- 2- ylidenemalonatc) and the juvenile honnone mimic pyriproxyfen 2 - [ 1- metyl -2 - (phenoxyphenoxy) ethoxy] pyridine, in different water and soil types under laboratory conditions had been studied. The degradation of isoprothiolane was slightly faster than pyriproxyfen in water, but in soil pyriproxyfen was more degradable than isoprothiolanec The adsorption! desorption behaviour of these two compounds was also investigated u,nder laboratory conditions. on two Egyptian soils, the pyriproxyfen adsorbed more than isoprothiotanc. Also desorption of pyriproxyfen was much less than isoprothiolane. The downward movement was also studied in prepared soil columns, the isoprothiolane was more mobile . than pyriproxyfen, and- this is in harmony with the results of adsorption/ desorption studies. The decontamination• of these two compounds, i.e. p,p-DDT, fenitrothion and fenepropathrin residues from contaminated water by using natural adsorbents, i.e. charcoal, vermiculite, peat moss and ground nut hull, the charcoal and ground nut hull was satisfactory in removing these pesticides residues from water more than vem1iculite and peat moss.