Lin Chunye, Li Peizhong, Cheng Hongguang, Ouyang Wei
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, 100875, China.
PLoS One. 2015 Apr 20;10(4):e0124294. doi: 10.1371/journal.pone.0124294. eCollection 2015.
The wetland Argialbolls pedon was chosen to investigate the effects of pedogenic processes and anthropogenic activities on the vertical distribution of lead and mercury concentration and to assess the potential use of soil as an archive of atmospheric Pb and Hg pollution. The soil was sampled from 5 cm from the surface to a depth of 90 cm at two locations in the Sanjiang Plain in northeastern China. The soil was analyzed for pH, soil organic matter (SOM), Fe, Mn, and Al. The results indicate that the SOM concentration gradually decreased with depth, while Fe and Mn were reductively leached from the upper horizons and accumulated significantly in the lower argillic horizons. Atmospheric Pb and Hg deposition and their redistribution during the pedogenic process led to a unique vertical distribution in the wetland Argialbolls. Overall, Pb was leached from the upper horizons and then accumulated in the lower argillic horizons. However, the Hg concentration decreased with depth, following the SOM distribution. The Pb concentration was significantly correlated to the Fe and Mn concentrations in the Argialbolls profiles, while the Hg concentration was significantly correlated with SOM. Post-depositional mobility along the wetland Argialbolls profile is higher for Pb and low for Hg. Therefore, the Argialbolls profile does not provide an accurate reconstruction of atmospheric Pb deposition, but might provide an accurate reconstruction of net atmospheric Hg deposition.
选取湿地黏化暗沃土土体来研究成土过程和人为活动对铅和汞浓度垂直分布的影响，并评估土壤作为大气铅和汞污染档案的潜在用途。在中国东北三江平原的两个地点，从地表以下5厘米至90厘米深度采集土壤样本。对土壤的pH值、土壤有机质（SOM）、铁、锰和铝进行了分析。结果表明，SOM浓度随深度逐渐降低，而铁和锰从上覆土层中被还原淋溶，并在下部黏化土层中显著积累。大气铅和汞的沉积及其在成土过程中的再分配导致了湿地黏化暗沃土中独特的垂直分布。总体而言，铅从上覆土层中淋溶出来，然后在下部黏化土层中积累。然而，汞浓度随深度降低，与SOM分布一致。在湿地黏化暗沃土土体剖面上，铅的沉积后迁移性较高，汞的沉积后迁移性较低。因此，黏化暗沃土土体剖面不能准确重建大气铅沉积，但可能提供大气汞净沉积的准确重建。
