大田条件下污泥施用土壤中全氟烷酸化合物的玉米吸收和传输

Uptake and translocation of perfluoroalkyl acids in biosolids-amended soils and plants

本文采集了山东长期污泥施用地区的污泥肥料、污泥施用土壤和农作物玉米(Zea mays L.),研究了全氟烷酸化合物(PFAAs,11种全氟烷基羧酸(PFCAs)以及5种全氟烷基磺酸(PFSAs))在污泥施用土壤-植物中的吸收与传输过程.污泥肥料中检测到了11种PFCAs以及4种PFSAs,PFAAs总含量为284.2 ng·g^(-1)干重(dw),其中全氟辛烷羧酸(PFOA)和全氟辛烷磺酸(PFOS)为主要检出物.污泥施用土壤中PFAAs总量为16.3—56.4 ng·g^(-1)dw,各PFAAs在污泥施用土壤中的分布与其在污泥肥料中的分布一致,表明土壤中的PFAAs主要来自污泥肥料.PFAAs在玉米各组织中分布特征为根>叶>茎,PFAAs在根、茎和叶中的含量随土壤中含量的增加而增加.玉米对PFCAs和PFSAs的根富集因子RCFs(Croot/Csoil)分别为1.26—8.69和1.18—4.22,RCFs值与碳链长度未呈显著相关性; PFAAs从根到茎的传输因子TFr-s(Cstraw/Croot)和从茎到叶的传输因子TFs-l(Cleaf/Cstraw)与PFAAs的碳链长度呈显著负相关(P <0.01).

Biosolids,soil and maize（ Zea mays L.） samples were collected from biosolids-amended fields in Shandong Province. Uptake and translocation of perfluoroalkyl acids（ PFAAs,eleven perfluorocarboxylic acids（ PFCAs） and five perfluorosulfonic acids（ PFSAs）） in the soil-plant system were studied. Eleven PFCAs and four PFSAs were detected quantitatively in biosolids. Total concentration of PFAAs in biosolids was 284.2 ng·g-1 dry weight（ dw）,with perfluorooctanoic acid（ PFOA） and perfluorooctane sulfate（ PFOS） as two dominant species. Total contents of PFAAs in biosolids-amended soils ranged from 16. 3 to 56. 4 ng·g-1 dw. The profile of PFAAs in biosolidsamended soils was consistent with that in biosolids,indicating that PFAAs in soils were mainly from the biosolids. The distribution of PFAAs in maize followed the order of roots 〉leaves 〉straws. The levels of PFAAs in maize tissues increased with those in soils. The root concentration factors（ RCFs,Croot/Csoil） of PFCAs and PFSAs ranged from 1.26 to 8.69 and from 1.18 to 4.22,respectively. The transfer factors from roots to straws（ TFr-s,Cstraw/Croot） and from straws to leaves（ TFs-l,Cleaf/Cstraw） correlated negatively with PFAA carbon chain length（ P〈 0.05）.