Cui Hongbiao, Fan Yuchao, Fang Guodong, Zhang Houxi, Su Binbin, Zhou Jing
School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy Sciences, Nanjing 210008, China.
Ecotoxicol Environ Saf. 2016 Dec;134P1:148-155. doi: 10.1016/j.ecoenv.2016.07.005. Epub 2016 Sep 8.
This study evaluated the efficiency of apatite, lime and charcoal in regulating Cu and Cd leachability (toxicity characteristic leaching and synthetic precipitation leaching procedures), availability (CaCl and MgCl) and bioaccessibility (simplified bioaccessibility extraction test) in a heavy metal-contaminated soil. Both soil pH and soil organic carbon content were investigated during the five-year field study. The results showed that soil pH and soil organic carbon content increased with application of amendments, but decreased with time in both the control and amended plots. Moreover, the leachability, availability and bioaccessibility of Cu and Cd in amended soils all significantly decreased compared with the control, but increased over time. Pearson's correlation analysis showed that soil pH was significantly negatively correlated with the concentrations of available, leachable and bioaccessible Cu and Cd. Bioaccessible Cu and Cd were positively correlated with the concentrations of available and leachable Cu and Cd, but they were not significantly correlated with soil total Cu and total Cd. Stepwise multiple regression analysis indicated that the variability in bioaccessible Cu and Cd was well explained by MgCl-extractable Cu, CaCl-extractable Cd and pH, respectively. Although the longevity of amendments decreased with time, apatite was the most effective in decreasing the availability of Cu, compared with lime and charcoal. These findings provide valuable insights for risk management during long-term in situ immobilization of heavy metals in contaminated soils.
本研究评估了磷灰石、石灰和木炭在调节重金属污染土壤中铜和镉的浸出性（毒性特征浸出和合成沉淀浸出程序）、有效性（氯化钙和氯化镁提取）和生物可利用性（简化生物可利用性提取试验）方面的效率。在为期五年的田间研究中，对土壤pH值和土壤有机碳含量进行了调查。结果表明，添加改良剂后土壤pH值和土壤有机碳含量增加，但在对照区和改良区均随时间下降。此外，与对照相比，改良土壤中铜和镉的浸出性、有效性和生物可利用性均显著降低，但随时间增加。Pearson相关性分析表明，土壤pH值与有效态、可浸出态和生物可利用态铜和镉的浓度显著负相关。生物可利用态铜和镉与有效态和可浸出态铜和镉的浓度呈正相关，但与土壤总铜和总镉无显著相关性。逐步多元回归分析表明，分别用氯化镁提取的铜、氯化钙提取的镉和pH值可以很好地解释生物可利用态铜和镉的变异性。尽管改良剂的效果随时间下降，但与石灰和木炭相比，磷灰石在降低铜的有效性方面最有效。这些发现为污染土壤中重金属长期原位固定过程中的风险管理提供了有价值的见解。
