Potential Influence of Ocean Acidification on Deep-Sea Fe?Mn Nodules: Results from Leaching Experiments
Potential Influence of Ocean Acidification on Deep-Sea Fe?Mn Nodules: Results from Leaching Experiments
复制标题
海洋酸化对深海铁锰结核的潜在影响：淋滤实验结果
DOI：
10.1007/s10498-017-9320-z
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发表时间：
2017
影响因子：
1.6
通讯作者：
Suzuki Atsushi
中科院分区：
文献类型：
--
作者：
Wang Quan;Kawahata Hodaka;Manaka Takuya;Yamaoka Kyoko;Suzuki Atsushi
随着CO2排放量的不断增加，海水的pH值可能在未来几个世纪内大幅下降。深海环境更容易受到pH值下降的影响，因为碳酸盐补偿深度以下的深海沉积物往往完全没有碳酸盐颗粒。为了评估深海沉积物释放重金属的潜在风险，利用pH值为7.1至8.6的磷酸盐缓冲溶液（NBS标度）进行浸出实验，对铁锰结核和远洋粘土中元素的流动性进行了研究。结果表明，随着pH值的降低，Li、B、Mg、Si、Sc、Sr、Ba、Tl、U等元素的浸出增强，而V、Cu、Mo、Cd、W等元素的浸出减少。淋滤液中的元素主要来源于可交换态，且易受吸附-解吸过程的影响。大多数元素的浓度没有超过广泛使用的国际水质标准，表明未来海洋酸化造成的pH值变化可能不会增加深海结核采矿作业期间重金属释放的风险。
With the continuous rise in CO2emissions, the pH of seawater may decrease extensively in the coming centuries. Deep-sea environments are more vulnerable to decreasing pH since sediments in deep oceans below the carbonate compensation depth (CCD) are often completely devoid of carbonate particles. In order to assess the potential risk of heavy metal release from deep-sea deposits, the mobility of elements from ferromanganese (Fe–Mn) nodules and pelagic clays was examined by means of leaching experiments using phosphate buffer solutions ranging in pH from 7.1 to 8.6 (NBS scale). With decreasing pH, the results showed an enhanced leaching of elements such as Li, B, Mg, Si, Sc, Sr, Ba, Tl, and U, but a reduced leaching of V, Cu, Mo, Cd, and W. Elements in leachates originate mainly from exchangeable fractions, and tend to be affected by sorption–desorption processes. Concentrations of most elements did not exceed widely used international water quality criteria, indicating that changes in pH caused by future ocean acidification may not increase the risk of heavy metal release during deep-sea nodule mining operations.