Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences, Guizhou University & State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, CAS, Guiyang 550025, China.
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences, Guizhou University & State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, CAS, Guiyang 550025, China.
Ecotoxicol Environ Saf. 2022 Sep 15;243:113963. doi: 10.1016/j.ecoenv.2022.113963. Epub 2022 Aug 12.
This study investigated sediment-bound magnetic properties and selected trace elements level in the karst ditch wetland, Caohai National Nature Reserve, Guizhou Province, China. Sediment-bound magnetic signals were quantified using low-frequency mass magnetic susceptibility (χLF), anhysteretic remanent magnetization susceptibility (χARM), saturation isothermal remanent magnetization (SIRM), and percentage frequency-dependent susceptibility (χfd%). Concentrations of Cd, Cr, Sb and Zn were determined using inductively coupled plasma mass spectrometry. Sediment χLF, χARM, SIRM, and χfd% were higher than those of bedrocks and mainly altered by the pedogenic processes. The estimated χfd% ranged from 6.15 % to 14.62 % and reflected the magnetic grain sizes were largely concentrated in the range of superparamagnetic particles. The elevated concentrations of sediment-bound Cd, Cr, Sb, and Zn supported the significant contribution of the anthropogenic sources in the karst ditch wetlands. The weak relationship between magnetic signals and selected trace elements (p < 0.05) suggested the occurrence of few sediment-bound iron-containing minerals associated with selected trace elements. These results indicated that a minor contribution of anthropogenic sources of selected trace elements to the elevated sediment magnetic signals in the karst ditch wetlands.
本研究调查了中国贵州省草海国家自然保护区岩溶沟湿地的沉积物磁性特征和选定微量元素水平。使用低频质量磁化率（χLF）、无磁滞剩磁磁化率（χARM）、饱和等温剩磁（SIRM）和频率磁化率（χfd%）定量表示沉积物的磁性信号。采用电感耦合等离子体质谱法（ICP-MS）测定了沉积物中 Cd、Cr、Sb 和 Zn 的浓度。沉积物的 χLF、χARM、SIRM 和 χfd%均高于基岩，主要受成土过程的影响。估算的 χfd%范围为 6.15%至 14.62%，反映了磁性颗粒大小主要集中在超顺磁颗粒范围内。沉积物中 Cd、Cr、Sb 和 Zn 含量的升高支持了人为源在岩溶沟湿地中的重要贡献。磁性信号与选定微量元素之间的弱相关性（p<0.05）表明，与选定微量元素相关的含铁矿物的存在很少。这些结果表明，人为源对岩溶沟湿地沉积物磁性信号升高的选定微量元素的贡献较小。
