点源排放六氯苯在植物中的分布研究

Distribution of HCB Discharged from a Chemical Plant in Plants

以武汉某工业区为对象,分析了排污渠、周围大河和农田植物及根际土壤中六氯苯（HCB）的分布特征及影响因素.结果表明,采样区内植物和土壤均受到不同程度的HCB污染,植物中HCB浓度（以干重计,下同）为4.45-1 189.89μg.kg^-1,根际土壤中为27.93-3 480.71μg.kg^-1.排污渠和大河沿岸植物和根际土壤中HCB含量相对较高.排污渠内木本植物对HCB富集程度大于草本植物,富集系数（RCF）分别为0.41-2.55和0.01-1.34.不同农田植物中HCB含量差异很大（4.45-333.1μg.kg^-1）,而同种植物不同部位对HCB的富集也不相同,例如,芋头果实、根和茎叶HCB含量分别为318.77、281.02和10.94μg.kg^-1.排污渠和农田植物中HCB含量与根际土壤中HCB含量无相关性,与脂肪含量显著相关.大河南岸植物和根际土壤中HCB含量随着与排放口距离的增加呈现显著降低趋势,植物根和茎叶中HCB含量与根际土壤中的HCB显著相关,但与脂肪含量无相关性.植物中HCB分布特征受到污染源强、脂肪含量和HCB在植物体内的分配-迁移模式影响.

The distribution characteristics of hexachlorobenzene （HCB） in plant and rhizosphere soil in contamination conduit, a nearby river and a cropland were studied and the impact factors were also discussed. The results are summarized as follows： the range of the HCB concentration in plant and rhizosphere soil in investigation area were respectively from 4.45 μg·kg^-1 to 1 189.89 μg·kg^-1 （dw） and from 27.93 μg· kg^-1 to 3 480.71 μg· kg^-1 （dw）. Higher enrichment of HCB in woodplant than herbs due to higher fat concentration in woodplant in the contamination conduit and the rich concentration factor of woodplant and herbs were 0.41-2.55 and 0.01-1.34. The range of HCB concentrations in plants in nearby croplands was significantly wide （4.45-333.1 μg· kg^-1 ） while HCB concentrations in different parts of plant were various, e.g. HCB concentrations in fruit, root and shoot of taro were 318.77 μg·kg^-1 , 281.02 μg·kg^-1 and 10.94 μg·kg^-1. There was a remarkable positive relation between the concentrations of HCB in plant and fat concentration of plant while no relativity between the concentrations of HCB in plant and those in ground soils in the contamination conduit and cropland. The concentration levels of HCB in plant and rhizosphere soil in river were dramatically decreased with increasing distance from contaminated conduit. There was a remarkable positive relation between the concentrations of HCB in plant and those in ground soils but no relation between concentrations of HCB in plant and fat concentration of plant in river. The distribution characteristics of HCB in plants were influenced by contaminated levels, fat concentration and Partition-transfer model.