随着经济、社会的快速发展,国内外众多淡水湖泊及其水源地受到了不同程度的有机物污染,严重影响了饮用水及湖泊生态系统的安全。生物有效性是表征污染物生态风险的重要指标之一。近年来,生物有效性相关研究备受关注。
在国家自然科学基金“含水生植物脂半透膜被动采样装置的研制及其在湖泊水源地有机污染物的原位监测和生物有效性研究中的应用”(21121107118)等项目的资助下,中国科学院南京地理与湖泊研究所陶玉强博士等利用仿生半透膜被动采样技术(三油酸甘油酯---醋酸纤维素复合膜),深入开展了安徽省南漪湖沉积物岩心中多环芳烃百年时间尺度的生物有效性及其相关机理研究。与传统的化学提取、铜锈环棱螺培养等方法相比,仿生半透膜被动采样技术具有准确、操作简单,无需前处理,节省试剂和时间,可避免生物培养易死亡、物种差异大、生物降解,对沉积物有机质性质变化灵敏等众多优点;研究借助傅里叶变化红外光谱和紫外-可见光谱解析了沉积物岩心中有机质性质随埋藏时间的变化规律,结合沉积物岩心中黑炭(black carbon)分析,并通过有机质性质随埋藏时间的变化规律与沉积物岩心中生物有效性之间的耦合关系,揭示了沉积物岩心中有机质随埋藏时间的增加而引起的芳香性增强,是导致沉积物岩心自上而下生物有效性逐渐降低的主要原因;探讨了不同理化性质的有机污染物百年时间尺度生物有效性的差异及其相关机理。
相关成果近日在环境科学领域刊物Environmental Science and Technology上发表
这是陶玉强博士等人继首次将含脂半透膜被动采样技术应用于土壤介质(Water Research,2008,42,754-762;Environmental Pollution,2009, 157, 545-551)及有机污染物对植物的生物有效性研究(Journal of Agricultural and Food Chemistry, 2008, 56, 10817-10823)之后,再次首次在国际上将被动采样技术应用到有机污染物百年时间尺度的生物有效性研究,拓展了被动采样技术的应用领域,促进了对野外大时间尺度生物有效性的认识,为生物有效性研究提供了有力的借鉴方法。(生物谷Bioon.com)
doi:10.1021/es203102b
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Triolein Embedded Cellulose Acetate Membrane as a Tool to Evaluate Sequestration of PAHs in Lake Sediment Core at Large Temporal Scale
Yuqiang Tao*, Bin Xue, Shuchun Yao, Jiancai Deng, and Zhifan Gui
Although numerous studies have addressed sequestration of hydrophobic organic compounds (HOCs) in laboratory, little attention has been paid to its evaluation method in field at large temporal scale. A biomimetic tool, triolein embedded cellulose acetate membrane (TECAM), was therefore tested to evaluate sequestration of six PAHs with various hydrophobicity in a well-dated sediment core sampled from Nanyi Lake, China. Properties of sediment organic matter (OM) varying with aging time dominated the sequestration of PAHs in the sediment core. TECAM-sediment accumulation factors (MSAFs) of the PAHs declined with aging time, and significantly correlated with the corresponding biota-sediment accumulation factors (BSAFs) for gastropod (Bellamya aeruginosa) simultaneously incubated in the same sediment slices. Sequestration rates of the PAHs in the sediment core evaluated by TECAM were much lower than those obtained from laboratory study. The relationship between relative availability for TECAM (MSAFt/MSAF0) and aging time followed the first order exponential decay model. MSAFt/MSAF0 was well-related to the minor changes of the properties of OM varying with aging time. Compared with chemical extraction, sequestration reflected by TECAM was much closer to that by B. aeruginosa. In contrast to B. aeruginosa, TECAM could avoid metabolism and the influences from feeding and other behaviors of organisms, and it is much easier to deploy and ready in laboratory. Hence TECAM provides an effective and convenient way to study sequestration of PAHs and probably other HOCs in field at large temporal scale.