Department of Life Sciences, University of Siena, Via Mattioli 4, 53100 Siena, Italy.
Department of Physical Sciences, Earth and Environment, University of Siena, Via Mattioli 4, 53100 Siena, Italy.
Sci Total Environ. 2021 Jan 1;750:141669. doi: 10.1016/j.scitotenv.2020.141669. Epub 2020 Aug 18.
Abandoned mine sites are a cause of great environmental concern, being potential sources of toxic elements for adjacent aquatic ecosystems with intrinsic difficulties for their management (i.e. episodic nature of pollution, technical difficulties and high costs of monitoring, remoteness). Aquatic macrophytes can find effective application in these situations, providing cost-effective data for instream water quality assessment. In this study, native and transplanted specimens of the aquatic moss Platyhypnidium riparioides were used to evaluate metal(loid) contamination in a river receiving multiple acidic and metalliferous drainages from sulphide mineralized areas and derelict mines. Analysis of native P. riparioides thalli was used to identify, in the upland course of the river, the pattern of contamination (As, Cd, Cu, Pb and Zn) which was related to the geo-environmental features of the watershed and the nearby historical mining areas. Attenuation of metal(loid) availability in the lowland river, apparently due to eco-hydrological and physic-chemical processes, was also highlighted by spatial trends of concentrations data of native and transplanted moss. The latter, deployed for 21 days at specific stretches of the river and in a tributary hydrologically connected with a dismissed mine, supported the identification of point sources (i.e. mine effluents, metallurgical waste piles amassed on the banks of the river) and the reckoning of their quantitative impact on different segments of the watercourse. By exploring multi-elemental and native-to-transplant relationships, differences in metal(loid) accumulative capacities were recognized between sampled thalli and exposed moss bags in relation to the severity of the contamination. The observed discrepancy in the accumulation of As, Fe, Ni and Pb in highly contaminated areas between native and transplanted moss of P. riparioides raises questions on the possible competing mechanisms of element uptake and retention. These findings prompt studies to discern possible limitations of the transplanting moss technique under extreme stream-quality conditions.
废弃矿山是一个引起极大环境关注的问题，它们是邻近水生生态系统中有毒元素的潜在来源，对其管理具有内在的困难（即污染的间歇性、监测的技术困难和高成本、偏远）。水生大型植物在这些情况下可以得到有效应用，为河流内水质评估提供具有成本效益的数据。在这项研究中，使用本地和移植的水生苔藓 Platyhypnidium riparioides 标本来评估接收来自硫化物矿化区和废弃矿山的多种酸性和金属排水的河流中的金属（类）污染。分析本地 P. riparioides 藻体，以确定河流上游地区的污染模式（As、Cd、Cu、Pb 和 Zn），这与流域的地球环境特征和附近的历史采矿区有关。由于生态水文学和物理化学过程，低地河流中金属（类）可用性的衰减也通过本地和移植苔藓浓度数据的空间趋势得到了强调。后者在河流的特定河段和与废弃矿山有水文联系的支流中部署了 21 天，支持了对点源（即矿山废水、堆积在河流两岸的冶金废物堆）的识别，并对其对不同河段的定量影响进行了估算。通过探索多元素和本地到移植的关系，识别出了采样藻体和暴露的苔藓袋之间的金属（类）累积能力差异，这与污染的严重程度有关。在高度污染地区，观察到本地和移植的 P. riparioides 苔藓中 As、Fe、Ni 和 Pb 的积累差异，这引发了对元素吸收和保留可能存在竞争机制的质疑。这些发现促使研究人员在极端溪流水质条件下，识别移植苔藓技术可能存在的局限性。
