Effects of a natural sepiolite bearing material and lime on the immobilization and persistence of cadmium in a contaminated acid agricultural soil
Effects of a natural sepiolite bearing material and lime on the immobilization and persistence of cadmium in a contaminated acid agricultural soil
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DOI：
10.1007/s11356-018-1988-0
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发表时间：
2018-08-01
影响因子：
5.8
通讯作者：
Luo, Yongming
中科院分区：
文献类型：
--
作者：
Cao, Xueying;Hu, Pengjie;Luo, Yongming
土壤镉 (Cd) 污染对人类健康和环境质量构成重大威胁。修复的长期有效性和持久性是评估用于修复受潜在有毒金属污染的土壤的改良技术的两个重要标准。在本研究中，我们研究了天然海泡石承载材料（NSBM，含 15% 海泡石）和研磨石灰石（相当于 > 98.0% CaO）对土壤 pH 值、镉生物有效性和小白菜 (Brassica chinensis L.) 镉积累的修复持久性，这些作物在含有不同 NSBM 量（0、0.2、 0.5、1、2 和 5%）。第一季土壤pH值范围为5.21至7.76，第二季土壤pH值4.30至7.34，第三季土壤pH值4.23至7.80，第四季土壤pH值4.33至6.98，并随着NSBM施用量的增加而显着增加。四个种植季节土壤CaCl2-Cd和地上部Cd浓度与对照相比分别下降8.11%~99.2%和6.58%~94.5%。土壤CaCl2-Cd与土壤pH值呈显着负相关。 0.1%石灰和NSBM联合使用比单独使用NSBM效果更好，特别是当NSBM的施用量为E、2%时。此外，单独添加 NSBM（ae> 2% 或 ae> 1% NSBM 与 0.1% 石灰联合处理）的小白菜组织 Cd 浓度符合中国和欧洲法规允许的四种作物的最大允许浓度（MPC）。根据本研究，在土壤pH > 6.38和CaCl2-Cd < 14 mu g kg(-1)的情况下，测试土壤中的安全作物生产是可能的，并且不加或加石灰的NSBM固定土壤Cd是控制土壤Cd转移到食物链中的潜在可行方法。
Soil contamination with cadmium (Cd) represents a substantial threat to human health and environmental quality. Long-term effectiveness and persistence of remediation are two important criteria for the evaluation of amendment techniques used to remediate soils polluted with potentially toxic metals. In the current study, we investigated the remediation persistence of a natural sepiolite bearing material (NSBM, containing 15% sepiolite) and ground limestone (equivalent to > 98.0% CaO) on soil pH, Cd bioavailability, and Cd accumulation by pak choi (Brassica chinensis L.) during the growth of four consecutive crops in a Cd-contaminated acid soil with different amounts of NSBM (0, 0.2, 0.5, 1, 2, and 5%). Soil pH levels ranged from 5.21 to 7.76 during the first crop, 4.30 to 7.34 during the second, 4.23 to 7.80 during the third, and 4.33 to 6.98 during the fourth, and increased significantly with increasing the application rate of NSBM. Soil CaCl2-Cd and shoot Cd concentrations decreased by 8.11 to 99.2% and 6.58 to 94.5%, respectively, compared with the control throughout the four cropping seasons. A significant negative correlation was found between soil CaCl2-Cd and soil pH. Combined use of 0.1% lime and NSBM showed greater effects than NSBM alone, especially, when the application rate of NSBM was E, 2%. Moreover, pak choi tissue Cd concentrations in the treatments with NSBM addition alone at ae> 2% or at ae> 1% NSBM combined with 0.1% lime met the maximum permissible concentration (MPC) over the four crops, allowed by the Chinese and European regulations. Based on the present study, safe crop production in the test soil is possible at a soil pH > 6.38 and CaCl2-Cd < 14 mu g kg(-1), and soil Cd immobilization by NSBM without or with lime is a potentially feasible method of controlling the transfer of soil Cd into the food chain.