College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China; Hunan Engineering Laboratory for Control of Rice Quality and Safety, Changsha, 410004, China.
College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China; Hunan Engineering Laboratory for Control of Rice Quality and Safety, Changsha, 410004, China.
Environ Pollut. 2020 May;260:113970. doi: 10.1016/j.envpol.2020.113970. Epub 2020 Jan 16.
Nano-FeO-modified biochar (BC-Fe) was prepared by the coprecipitation of nano-FeO on a rice husk biochar surface. The effects of BC-Fe on cadmium (Cd) bioavailability in soil and on Cd accumulation and translocation in rice (Oryza sativa L. cv. 'H You 518') were investigated in a pot experiment with 7 application rates (0.05-1.6%, w/w). BC-Fe increased the biomass of the rice plants except for the roots and affected the concentration and accumulation of Cd and Fe in the plants. The Cd concentrations of brown rice were significantly decreased by 48.9%, 35.6%, and 46.5% by the 0.05%, 0.2%, and 0.4% BC-Fe treatments, respectively. Soil cation exchange capacity (CEC) increased by 9.4%-164.1% in response to the application of BC-Fe (0.05-1.6%), while the soil Cd availability decreased by 6.81%-25.0%. However, 0.8-1.6% BC-Fe treatments promoted Cd transport to leaves, which could increase the risk of Cd accumulation in brown rice. Furthermore, BC-Fe application promoted the formation of iron plaque and enhanced the root interception of Cd. The formation of iron plaque reduced the toxicity of Cd to rice roots, but this barrier effect was limited and had an interval threshold (DCB-Fe: 22.5-27.3 g·kg) under BC-Fe treatments.
纳米 FeO 修饰生物炭（BC-Fe）通过纳米 FeO 在稻壳生物炭表面共沉淀制备。采用盆栽试验研究了 7 种施用量（0.05-1.6%，w/w）下 BC-Fe 对土壤中镉生物有效性及水稻（Oryza sativa L. cv. 'H You 518'）镉积累和迁移的影响。BC-Fe 增加了除根以外的水稻植株生物量，并影响了植株中 Cd 和 Fe 的浓度和积累。0.05%、0.2%和 0.4% BC-Fe 处理分别使糙米中 Cd 浓度降低了 48.9%、35.6%和 46.5%。BC-Fe（0.05-1.6%）的应用使土壤阳离子交换容量（CEC）增加了 9.4%-164.1%，而土壤 Cd 有效性降低了 6.81%-25.0%。然而，0.8-1.6%BC-Fe 处理促进了 Cd 向叶片的转运，这可能增加糙米中 Cd 积累的风险。此外，BC-Fe 的应用促进了铁斑的形成，并增强了根对 Cd 的截留。铁斑的形成降低了 Cd 对水稻根系的毒性，但这种屏障效应是有限的，在 BC-Fe 处理下存在一个间隔阈值（DCB-Fe：22.5-27.3 g·kg）。
