Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China.
Faculty of Engineering, China University of Geosciences, Wuhan 430074, China.
Int J Environ Res Public Health. 2020 Feb 2;17(3):928. doi: 10.3390/ijerph17030928.
Karst water is rich in calcium ions (Ca) and exhibits poor metal availability and low biodegradation efficiency. This study sought to analyze the effects and mechanisms of Ca on lead (Pb) removal and absorption by (a floating plant common in karst areas). Moreover, the morphology and functional groups of in water were characterized via SEM, and FTIR. The results demonstrated that the removal rate of Pb in karst water (85.31%) was higher than that in non-karst water (77.04%); however, the Pb bioconcentration amount (BCA) in roots in karst water (1763 mg/kg) was lower than that in non-karst water (2143 mg/kg). With increased Ca concentrations (60, 80, and 100 mg/L) in karst water, the Pb removal rate increased (85.31%, 88.87%, and 92.44%), the Pb BCA decreased (1763, 1317, and 1095 mg/kg), and the Ca BCA increased (6801, 6955, and 9368 mg/kg), which was attributed to PbCO and PbSO precipitation and competitive Ca and Pb absorption. High Ca concentrations increased the strength of cation exchange, alleviated the fracture degree of fibrous roots, reduced the atrophy of vascular bundles, protected the cell wall, promoted C-O combined with Pb, enhanced the strength of O‒H, SO, C=O, and reduced the oxidization of alkynyl acetylene bonds.
喀斯特水中富含钙离子（Ca），金属可用性差，生物降解效率低。本研究旨在分析 Ca 对（一种在喀斯特地区常见的漂浮植物）去除和吸收水中 Pb 的影响和机制。此外，通过 SEM 和 FTIR 对 水中的形态和官能团进行了表征。结果表明，喀斯特水中 Pb 的去除率（85.31%）高于非喀斯特水中的去除率（77.04%）；然而，喀斯特水中 根部的 Pb 生物浓缩量（BCA）（1763 mg/kg）低于非喀斯特水中的 BCA（2143 mg/kg）。随着喀斯特水中 Ca 浓度（60、80 和 100 mg/L）的增加，Pb 的去除率增加（85.31%、88.87%和 92.44%），Pb 的 BCA 降低（1763、1317 和 1095 mg/kg），Ca 的 BCA 增加（6801、6955 和 9368 mg/kg），这归因于 PbCO 和 PbSO 的沉淀以及竞争的 Ca 和 Pb 吸收。高 Ca 浓度增强了阳离子交换的强度，减轻了纤维根的断裂程度，减少了维管束的萎缩，保护了细胞壁，促进了 C-O 与 Pb 的结合，增强了 O‒H、SO、C=O 的强度，并减少了炔基乙炔键的氧化。
