Center for Permafrost (CENPERM), Department of Geoscience and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K., Denmark; (Current affiliation) Department of Civil Engineering, Technical University of Denmark, Building 118, 2800 Lyngby, Denmark.
Akvaplan-niva AS, Framsenteret, Postbox 6606, Langnes, 9296 Tromsø, Norway.
Sci Total Environ. 2019 Dec 15;696:133903. doi: 10.1016/j.scitotenv.2019.133903. Epub 2019 Aug 13.
Mine tailings from the iron ore mine Sydvaranger Gruve have been deposited in Bøkfjorden, Northern Norway, for >40 years. This study investigates the environmental impacts of submarine tailings disposal one year after the cessation of the mine by combining analyses of total metal concentrations (nitric acid digestion) and metal fractionation patterns (sequential extraction procedure) of sediments with the metal uptake (bioassays) by sandworms (Alitta virens) exposed to Bøkfjorden sediment. The analyses focused on metals (As, Cd, Cr, Cu, Fe, Ni, Pb, Zn) in sediment cores retrieved from a horizontal transect of the fjord. High concentrations of the target metal iron was found in the fjord (>13,000 mg/kg). According to Norwegian sediment quality guidelines (SQG), cadmium (2.55 mg/kg) and lead (174 mg/kg) were the only metals to exceed good sediment quality at the source area of mine tailings discharge. Despite general low total metal concentrations, labile (summarized exchangeable, acid soluble, reducible fractions) and potentially labile (summarized labile and oxidisable fractions) pools of mine tailings-related metals of cadmium (10-82%), copper (25-88%) and lead (10-67%) were detected while iron were characterized as inert (residual fraction: 89-97%). Despite spatial trends in total metal concentrations presumed to originate from mine tailings (Cd, Cu, Fe, Pb), there were no correlations between total and labile fractions. This can be explained by the high concentrations of iron, which under oxidised forms are suggested to inhibit a high lability of other metals. The metal uptake of sandworms was generally high compared to similar studies and exceeded moderate contamination classes for all metals compared to Norwegian standard values. Both labile metal fractions (cadmium, copper and iron) and total metal concentrations (copper, iron) showed positive correlations (r > 0.6) with metal uptake. Thus, both the total and labile metal fractions can pose an environmental risk.
来自 Sydvaranger 铁矿的尾矿已在挪威北部的 Bøkfjorden 中存放了>40 年。本研究通过分析沉积物中的总金属浓度（硝酸消解）和金属形态（顺序提取程序）以及暴露于 Bøkfjorden 沉积物的沙蚕（Alitta virens）的金属吸收量（生物测定），结合在矿山停产后一年对海底尾矿处置的环境影响进行了综合调查。该分析集中在从峡湾水平横切线上采集的沉积物岩芯中的金属（As、Cd、Cr、Cu、Fe、Ni、Pb、Zn）。在峡湾中发现了高浓度的目标金属铁（>13,000mg/kg）。根据挪威沉积物质量指南（SQG），只有镉（2.55mg/kg）和铅（174mg/kg）超过了尾矿排放源区的良好沉积物质量。尽管总金属浓度普遍较低，但仍检测到与尾矿相关的金属（镉、铜和铅）的可利用（可交换、酸可溶、可还原部分）和潜在可利用（可利用和可氧化部分）池，而铁则被描述为惰性（残余部分：89-97%）。尽管存在总金属浓度的空间趋势（源自尾矿）（Cd、Cu、Fe、Pb），但总金属浓度与可利用分数之间没有相关性。这可以用铁的高浓度来解释，氧化形式的铁被认为会抑制其他金属的高活性。与类似的研究相比，沙蚕的金属吸收量通常较高，与挪威标准值相比，所有金属的中等污染程度均超过中度污染水平。可利用金属分数（镉、铜和铁）和总金属浓度（铜、铁）均与金属吸收量呈正相关（r>0.6）。因此，总金属分数和可利用金属分数都可能构成环境风险。
