本文選題：生物可利用性　切入點：遷移系數(shù)　出處：《環(huán)境科學與技術》2017年12期

【摘要】：農(nóng)田土壤重金屬污染不利于農(nóng)產(chǎn)品質(zhì)量以及人群健康,土壤重金屬的生物可利用性揭示了重金屬在土壤-農(nóng)作物間的遷移信息,該文以廣東省順德市農(nóng)田土壤為研究對象,通過分析土壤-蔬菜系統(tǒng)的重金屬含量與化學形態(tài),并利用相關性分析和聚類分析對土壤-蔬菜系統(tǒng)的重金屬生物可利用性及遷移系數(shù)進行研究。結(jié)果表明:研究區(qū)As、Cu、Hg、Mn、Ni、Pb的平均含量均大于廣東省背景值的2倍,尤其是Hg,86.2%超過國家農(nóng)田土壤環(huán)境質(zhì)量二級標準,而蔬菜重金屬含量大多數(shù)低于衛(wèi)生部頒布的最新食品衛(wèi)生標準。土壤重金屬可利用態(tài)含量表現(xiàn)為:MnCuPbHgNiAs,表明Mn、Cu、Pb和Hg具有更強的活性,同時,土壤屬性(pH值和OM值)對重金屬的生物可利用性和環(huán)境毒性具有影響意義。相比于土壤重金屬全量,土壤中重金屬的生物可利用態(tài)與蔬菜中重金屬含量之間具有更顯著的相關性,表明土壤重金屬可利用態(tài)較全量更適合表征重金屬對環(huán)境的毒性效應。基于重金屬可利用態(tài)的土壤-蔬菜遷移系數(shù)(TF_(avail))表現(xiàn)為:HgAsNi≥Mn≥Cu≥Pb,表明可利用態(tài)Hg、As和Ni更容易被蔬菜吸收,并且隨著土壤重金屬可利用態(tài)含量的升高,重金屬的遷移富集程度呈冪函數(shù)式降低,這可能是緣于植物生理學自我保護機制,使蔬菜對重金屬的吸收富集量保持在可控制范圍內(nèi)。
[Abstract]:Heavy metal pollution in farmland soil is harmful to the quality of agricultural products and the health of the population. The bioavailability of heavy metals in the soil reveals the information of heavy metal migration between soil and crops. This paper takes the farmland soil of Shunde City, Guangdong Province as the research object. The contents and chemical forms of heavy metals in soil-vegetable system were analyzed. Correlation analysis and cluster analysis were used to study the bioavailability and migration coefficient of heavy metals in soil-vegetable system. The results showed that the average content of Pb in the study area was 2 times higher than the background value of Guangdong Province. In particular, 86.2% of HgN exceeded the second grade standard of soil environmental quality in farmland, and most of the heavy metals in vegetables were lower than the latest food hygiene standards issued by the Ministry of Health. The available state contents of heavy metals in soil were: MnCuPbHgNiAs. the results showed that MnCuCu Pb and Hg had stronger activities. At the same time, the soil properties (pH and OM) have significant influence on the bioavailability and environmental toxicity of heavy metals, compared with the total amount of heavy metals in soil. There was a more significant correlation between the bioavailability of heavy metals in soil and the contents of heavy metals in vegetables. The results show that the available forms of heavy metals in soil are more suitable to characterize the toxic effects of heavy metals on the environment than the total ones, and the soil-vegetable transport coefficient based on the available forms of heavy metals is as follows: HgAsNi 鈮，

本文編號：1665522