钡盐厂周边土壤中钡的分布及其在植物中的富集

Barium distribution in soils and its accumulation in plants near a barium compounds industry

在实验分析的基础上,以天柱县某钡盐厂周边土壤和植物作为研究对象,探讨了钡及各形态钡在土壤中的分布规律和钡在钡盐厂周边本土植物中的富集现象、影响因素等。分析结果表明,钡盐厂周边土壤存在严重的钡富集现象,其周边2 km范围内土壤钡的含量范围为760.4～3 196 mg/kg。污染区土壤表层钡的分布受污染源的距离及所在风向的控制,各形态钡占总钡平均比例大小关系为:残渣态>Fe/Mn结合态>有机结合态>弱酸结合态;钡盐厂周边本土植物对钡具有不同的富集能力,钡在植物中的富集因植物种类不同而不同。钡盐厂周边本土植物对钡的富集除了受本身的富集能力及所在土壤钡含量的影响外,可能还与土壤pH、有机质及总氮等因素有关。文中地瓜、油茶、白菜、萝卜和辣椒为可食用性植物,其中地瓜中钡的含量高达2 858.7 mg/kg,富集系数为3.11,可食用性植物中的钡可以通过食物链进入人体,可能对人体健康造成潜在威胁。

This study carried out a series of experiments targeting the soil and plants around a barium compound industry in Tianzhu County, Guizhou province, in order to investigate the distribution of barium in the soils, the enrichment property in native plants and factors influencing barium enrichment. The results showed that barium was significantly enriched in the soils within 2 km from the factory, ranging from 760. 4 to 3 196 mg/kg. The spatial distribution revealed that the concentrations of barium in soil can be dominated by the distance from the factory and the wind direction. The percentage of barium of four different forms was ranked in descending order as： residual based, Fe/Mn based, organic matter based, and dilute acid based. Native plants varied in barium enrichment capacities according to plant species and barium concentration in soils, as well as soil pH value, organic matter and total nitrogen levels in the soils. Edible plants, for example sweet potato, sasanqua , cabbage , radish and capsicum are found with high barium concentration , among which sweet potato contained highest barium （2 858.7 mg/kg） and its barium accumulation factor could reach up to 3.11. The barium in those edible plants was consumed by local people and may cause a potential health risk.