National Demonstration Center for Environmental and Planning, College of Environment & Planning, Henan University, Kaifeng, 475004, China; Key Research Institute of Yellow River Civilization and Sustainable Development & Collaborative Innovation Center on Yellow River Civilization of Henan Province, Henan University, Kaifeng, 475004, China; Henan Engineering Research Center for Control & Remediation of Soil Heavy Metal Pollution, Henan University, Kaifeng, 475004, China.
National Demonstration Center for Environmental and Planning, College of Environment & Planning, Henan University, Kaifeng, 475004, China.
Ecotoxicol Environ Saf. 2020 Jul 1;197:110600. doi: 10.1016/j.ecoenv.2020.110600. Epub 2020 Apr 11.
Cadmium (Cd) contamination in agricultural soil is a worldwide environmental problem. In situ stabilization has been considered an effective approach for the remediation of Cd-contaminated agricultural soil. However, information about the long-term effects of amendment on soil properties and stabilization efficiency remains limited. In the present study, mercapto-functionalized nano-silica (MPTS/nano-silica) was used to stabilize Cd in contaminated agricultural soil under field conditions for three years (with application rates of 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1.0%). The application of MPTS/nano-silica reduced the soil aggregate stability (PDA) (14.8%) and available K (24.9%) and significantly increased the soil dehydrogenase (DHA) (43.4%), yield of wheat grains (33.5%) and Si content in wheat tissues (55.2% in leaf, 50.4% in stem, and 37.7% in husk) (p < 0.05). More importantly, MPTS/nano-silica decreased the leachability (36.0%) and bioavailability (54.3%) of Cd in the soil and transformed Cd into a more stable fraction. The content of Cd in wheat grains decreased by 53.9%, 61.9% and 54.1% in 2017, 2018 and 2019, respectively, in comparison with the control. These results indicated that MPTS/nano-silica has long-term stabilization effects on Cd in agricultural soil and is a potential amendment for the remediation of Cd-contaminated agricultural soils.
土壤中镉（Cd）污染是一个全球性的环境问题。原位稳定化被认为是修复 Cd 污染农田的有效方法。然而，关于改良剂对土壤性质和稳定效率的长期影响的信息仍然有限。本研究在田间条件下，使用巯基功能化纳米硅（MPTS/nano-silica）稳定 Cd 污染农田土壤，持续三年（施用率分别为 0%、0.2%、0.4%、0.6%、0.8%和 1.0%）。MPTS/nano-silica 的应用降低了土壤团聚体稳定性（PDA）（14.8%）和有效钾（24.9%），并显著增加了土壤脱氢酶（DHA）（43.4%）、小麦产量（33.5%）和小麦组织中的硅含量（叶片中为 55.2%，茎中为 50.4%，壳中为 37.7%）（p<0.05）。更重要的是，MPTS/nano-silica 降低了土壤中 Cd 的浸出率（36.0%）和生物有效性（54.3%），并将 Cd 转化为更稳定的形态。与对照相比，2017 年、2018 年和 2019 年，小麦籽粒中 Cd 的含量分别降低了 53.9%、61.9%和 54.1%。这些结果表明，MPTS/nano-silica 对农田土壤中 Cd 具有长期稳定化作用，是一种修复 Cd 污染农田的潜在改良剂。
