Amorphous arsenic sulfide nanoparticles in a shallow water hydrothermal system
Amorphous arsenic sulfide nanoparticles in a shallow water hydrothermal system
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浅水热液系统中的无定形硫化砷纳米粒子
DOI：
10.1016/j.marchem.2019.03.008
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发表时间：
2019
期刊：
影响因子：
3
通讯作者：
Bühring
中科院分区：
文献类型：
--
作者：
Durán-Toro;Brombach;Pichler;Rezwan;Bühring
热液可能含有微量元素，如砷（As），这对周围的生物群是有毒的。在这些类型的流体中，已经研究了As的生物利用度和生物转化，但到目前为止，总可溶性As（<200 nm）与纳米颗粒相中所含As的量的比率尚未报道。在这里，第一次，在纳米颗粒部分（200和20 nm之间）的存在下，描述了在海洋浅水热液系统中的富砷热液流体。在位于希腊米洛斯岛古乔里湾的热液系统中采集了扩散喷发的热液流体、孔隙水和海水样品，并研究了200和20 nm之间的组分（As 200 -20）。高达38%的可溶性砷存在于孔隙流体中的As 200 - 200组分中，10 - 20%在热液流体中，5%在海水中。通过扫描电子显微镜结合能量色散X射线能谱（SEM-EDX）、透射电子显微镜结合选区电子衍射（SAED）和动态光散射（DLS）对热液流体、孔隙水和海水中的颗粒进行了鉴定和表征。颗粒为球形形态，具有多分散的尺寸分布（PDI：0.37）和接近100 nm的直径。EDX研究证实了富含As和S的化学成分。SAED图谱显示不存在晶相，表明存在无定形硫化砷材料。这些结果带来讨论的纳米颗粒部分作为分散，生物利用度，在海洋沿海生态系统中的潜在有害影响的作用。
Hydrothermal fluids can contain trace elements such as arsenic (As), which are toxic to surrounding biota. In these kind of fluids, the bioavailability and biotransformation of As have been investigated but so far the ratio of total soluble As (<200 nm) versus the amount of As contained in a nanoparticulate phase has not been reported. Here, for the first time, the presence of As in the nanoparticulate fraction (between 200 and 20 nm) is described for arsenic-rich hydrothermal fluids in a marine shallow-water hydrothermal system. Samples of diffusively venting hydrothermal fluids, pore-water and seawater were collected in the hydrothermal system located in Paleochori Bay, Milos Island (Greece), and the fraction between 200 and 20 nm (As200-20) was studied. Up to 38% of the soluble arsenic was present within the As200-20fraction in pore fluids, 10 to 20% in hydrothermal fluids and 5% in seawater. Identification and characterization of particles in hydrothermal fluid, pore-water and seawater was performed by scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) with selected area electron diffraction (SAED) and dynamic light scattering (DLS). The particles are of spherical morphology with a polydisperse size distribution (PDI: 0.37) and diameters close to 100 nm. EDX studies confirmed a chemical composition rich in As and S. The SAED pattern revealed absence of a crystal phase indicating the presence of an amorphous arsenic sulfide material. These results bring into discussion the role of the nanoparticulate fraction for As dispersion, bioavailability, and potentially harmful effects in marine coastal ecosystems.