Xiaoliang Research Station for Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410221, China.
Xiaoliang Research Station for Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; South China National Botanical Garden, Guangzhou 510650, China.
J Hazard Mater. 2023 Feb 5;443(Pt B):130291. doi: 10.1016/j.jhazmat.2022.130291. Epub 2022 Oct 29.
Improper application of phosphorus (P) fertilizer during soil cadmium (Cd) immobilization reduces the efficiency of fertilizer and Cd remediation. In this study, we synthesized three types of nano-hydroxyapatite (NHAP) with different surface charges as slow-release P fertilizers during Cd immobilization. We also evaluated the effects of wollastonite application with or without NHAP addition, in comparison with triple superphosphate (TSP) or bulk hydroxyapatite, on Cd accumulation in Amaranthus tricolor L. The results showed that adding wollastonite significantly reduced P availability (23.5%) in the soil, but it did not inhibit plant P uptake. In wollastonite-amended soil, the application of negatively/positively charged NHAP significantly increased plant biomass by 643-865% and decreased Cd uptake by 74.8-75.1% compared to the unamended soil as well as showed greater efficiency than those with TSP. This was ascribed to the increased soil pH (from 3.94 to 6.52-6.63) and increased abundance of organic acids (including citric acid, malic acid, lactic acid, and acetic acid) secreted by plants. In addition, the P-preferring bacterial class Bacteroidia was specific to soils amended with both wollastonite and NHAP-. These results suggest that NHAP- may be an appropriate P fertilizer for soil Cd immobilization using wollastonite.
在土壤镉固定过程中，磷（P）肥的不当应用会降低肥料和镉修复的效率。在这项研究中，我们合成了三种具有不同表面电荷的纳米羟基磷灰石（NHAP），作为镉固定过程中的缓释 P 肥料。我们还评估了添加或不添加硅灰石时与添加三料过磷酸钙（TSP）或大块羟基磷灰石相比，硅灰石对苋菜中 Cd 积累的影响。结果表明，添加硅灰石显著降低了土壤中 P 的有效性（23.5%），但并未抑制植物对 P 的吸收。在添加硅灰石的土壤中，与未添加土壤以及 TSP 相比，添加带负电荷/正电荷的 NHAP 可使植物生物量分别增加 643-865%，Cd 吸收量减少 74.8-75.1%，效率更高。这归因于土壤 pH 值的增加（从 3.94 增加到 6.52-6.63）和植物分泌的有机酸（包括柠檬酸、苹果酸、乳酸和乙酸）的增加。此外，磷偏好细菌类杆菌纲是添加硅灰石和 NHAP-的土壤所特有的。这些结果表明，NHAP-可能是一种合适的 P 肥料，可用于使用硅灰石固定土壤中的 Cd。
