不同土壤腐殖酸对辛硫磷水解的影响

各种试验土壤腐殖酸的紫外吸收曲线相似,但吸收峰强度和E 465/E 665值差异较大,腐殖酸的腐殖化程度由大至小排序为：紫色潮土HA〉黄壤HA〉中性紫色土HA〉酸性紫色土HA,说明它们组成相似,结构和性质有差异。在此基础上,研究它们对辛硫磷水解的影响。结果表明,不同来源土壤腐殖酸均阻碍辛硫磷的水解,但它们的影响程度有明显的差异。腐殖酸溶液浓度越大,辛硫磷水解速率越慢,相同腐殖酸浓度下以腐殖化程度较高的紫色潮土的作用最大。初步说明辛硫磷的水解速率与土壤腐殖酸的浓度和腐殖化程度有关。

Influences of Humic Acids Isolated from Different Soils on Hydrolysis of Phoxim

The compositions of humic acids(HAs) in various soils were common in nature,but the aromatic structures,function groups,molecular weight,and the level of HAs from various soils were significantly different.On these base,the influences of HAs on hydrolysis of phoxim were studied.The results showed that the hydrolysis effect differed for soils that contained different level of HAs. With the concentration of HAs increasing,hydrolysis of phoxim decreased gradually,and the effect by acid purple soil with the lower level of HAs was distinct.Therefore,it may be conferred that the speed of hydrolysis of phoxim was related to the concentration of HAs and the level of HAs.