State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Ave. 163, Nanjing 210023, PR China.
Geological Survey of Jiangsu Province, Zhujiang Rd. 700, 210002, PR China.
Sci Total Environ. 2018 Jul 15;630:1374-1380. doi: 10.1016/j.scitotenv.2018.03.002. Epub 2018 Mar 7.
The prediction of metal bioavailability in soils is critical to metal risk assessments and the amount of dissolved metal in soils is a key factor determining bioavailability. Because the recently developed geochemical multi-surface models (MSMs) offer a promising tool for the determination of metal partitioning in soils, in this study, a MSM based on generic parameters was used to assess the bioavailability of Cd in wheat (Triticum aestivum L.) growing in 12 soils with a wide range of properties. The amount of MSM-calculated dissolved Cd correlated strongly with the amount of Cd uptake by wheat (R=0.873 for roots and R=0.837 for shoots), and the model's performance was better than that of chemical extraction methods (0.01M CaCl, 0.43M HNO and soil total Cd). The reactive fraction of soil organic matter, the soil/solution ratio, and the inclusion/exclusion of background cations influenced the calculation results. The best calculation condition was optimized. The application of the MSM was also examined in 84 wheat-soil samples from the field. The amount of Cd in wheat seeds had a stronger correlation with the amount of MSM-predicted Cd than with the amount of Cd obtained using chemical extraction methods. Our results suggested that MSM-calculated Cd is an effective indicator of the bioavailability of Cd in soils and demonstrated the utility of the method as a tool to assess the risk of Cd contamination in soils.
土壤中金属生物有效性的预测对于金属风险评估至关重要，而土壤中溶解金属的含量则是决定生物有效性的关键因素。由于最近开发的地球化学多表面模型（MSMs）为确定土壤中金属分配提供了一种很有前途的工具，因此在本研究中，使用了一种基于通用参数的 MSM 来评估 12 种具有广泛性质的土壤中 Cd 在小麦（Triticum aestivum L.）中的生物有效性。MSM 计算出的溶解 Cd 量与小麦对 Cd 的吸收量密切相关（根系为 R=0.873，地上部为 R=0.837），且模型的性能优于化学提取方法（0.01M CaCl、0.43M HNO 和土壤总 Cd）。土壤有机质的反应部分、土壤/溶液比以及背景阳离子的包含/排除都会影响计算结果。优化了最佳的计算条件。还在田间 84 个小麦-土壤样品中检验了 MSM 的应用。小麦种子中的 Cd 量与 MSM 预测的 Cd 量与化学提取方法获得的 Cd 量之间的相关性更强。我们的结果表明，MSM 计算出的 Cd 是土壤中 Cd 生物有效性的有效指标，并证明了该方法作为评估土壤中 Cd 污染风险的工具的实用性。
