淹水土壤中久效磷的降解及消失动态

本试验在实验室模拟土壤淹水条件下,研究微生物对久效磷残留及降解的影响。结果表明:在未经灭菌的土壤中,久效磷及其降解物的消失比在灭菌土壤中快,相应的回归方程为C_WT=5.4502e~(-0.0254)t,C_YT=5.8509—0.0423t,残留半衰期分别为27.3和69.2天。久效磷在淹水土壤中降解为甲醇可抽提态和不可抽提态残留物,对甲醇可抽提态残留物经TLC和红外光谱分析表明,其降解物为磷酸三酯、N-去甲基久效磷、O,O-二甲基乙烯基磷酸酯,0-去甲基久效磷,以及O,C-去甲基久效磷,但主要为磷酸三酯,其含量由母液中的5％增加到28—83％,这种降解过程,在未灭菌土壤中比在灭菌土壤中快。

DYNAMIC OF DEGRADATION AND DISAPPEARANCE OF MONOCROTOPHOS IN SUBMERGED SOIL

This test explored influence of soil microorganisms on residue and degradation, of moncrotophos by laboratory model.The experimental results indicated that the disappearance rates of monocrotophos and its degraded products were much faster in the unsteri-lized soil than that in the sterilized soil,and the regressive equations are CwT = 5.4502e-0.0254t,CYT = 5.8509-0.0423t respectively .Their half lives were 27.29 and 69.16 days respectively. Monocrotophos degraded into both methanol extractable and unextractable residues in the submerged soil.The analysis of 14C-methanol extractable. residue by TLC and ARG indicated that degraded products of monocrotophos were triether phosphate, ;N-de-methyl Azodrin, O, O-dimethyl-vinyl-phosphatc,O-demethyl Azodrin,and O, C-demethyl Azodrin.The principal degraded extratable product of monocrotophos was triether phosphate, which incresed from 5% of the parent solution of monocrotophos to a range of 28-83%, furthermore and its degradation process was much faster in the unterilized soil than in the sterilized soil.