不同有机质含量的土壤中DDT对小麦根系的生物有效性

Bioavailability of DDT in soils with various organic matter level to wheat roots

对不同有机质含量的土壤中,分别选用水、正己烷、正己烷/丙酮混合溶剂作为DDT的提取剂,用这3种提取剂逐级连续提取,研究了这3级提取剂所提取的DDT量的差别及其与小麦根吸收的关系。结果表明,有机氯的水提取量随土壤DOC的增加而上升,正己烷提取量随土壤TOC的增加而下降,正己烷/丙酮提取量随土壤TOC的增加而上升。根吸收与水提取量没有确定的关系,但与正己烷提取量具正相关关系,与正己烷/丙酮提取量有负相关关系。

A study was conducted to determine the distribution of DDT in soils containing various SOM concentrations and to study the relationship between the bioavailability and the quantity sequentially extracted using ASE with water, hexane and a mixed solvent of hexane and acetone as solvents. The result showed that the quantity extracted by water declined with the increasing of soil DOC, the quantity extracted by hexane declined with the increasing of TOC, and the quantity extracted by the hexane/acetone increased with the increasing of TOC as well. Bioavailability was not correlated with the quantity extracted by water, but correlated positively with the quantity extracted by hexane and negatively with that of hexane/acetone.