Mobility and retention of heavy metals, arsenic and sulphur in podzols at eight locations in northern Finland and Norway and the western half of the Russian Kola Peninsula     

Marja Liisa Räisänen  Galina Kashulina  Igor Bogatyrev 《Journal of Geochemical Exploration》1997,59(3):175-195

The mobility and retention of heavy metals, arsenic and sulphur in podzols from eight areas located north of the Arctic Circle in Finland, Norway and Russia were determined by analyzing the < 2.0 mm fraction, using an ammonium acetate (pH 4.5) extraction in addition to a concentrated nitric acid digestion for the humus samples, and a hot aqua regia digestion for the mineral soil samples. Total C, H and N concentrations were determined in humus and mineral soil samples with a CHN analyser.Ni, Cu, Co and As were strongly enriched in the humus layer in the contaminated sites (Monchegorsk, Kurka, Zapoljarnij) when compared to their concentrations in the parent tills and in podzols from the background sites. In most study sites the illuvial layer showed a low capacity to retain the metals and As, the exception included a strongly eroded profile at Monchegorsk, where Ni was tightly fixed in the illuvial layer while Cu was mobile. In contrast to metals, airborne S was not accumulated in the humus layer, but was accumulated in the illuvial layer, more markedly at eroded sites than in places where the humus was covered as at Monchegorsk.  相似文献   

砷污染治理背景下阳宗海浮游植物生物量的时空分布模式及驱动因子     

郑昕  陈丽  仇菲  张涛  张昭阳  尚丽  白宁静  陈小林  赵帅营  孔令阳  陈光杰 《湖泊科学》2024,36(1):34-42

在社会经济发展和流域开发持续的背景下,砷污染已成为我国部分水体面临的重要环境问题,目前对砷污染防控的生态效应与修复效果评价仍缺乏系统识别。湖泊生态系统中浮游植物是重要的生产者,砷等重金属污染可以直接影响浮游植物生长、物种演替和初级生产力水平,浮游植物已成为指示砷污染水平及其生态效应的敏感指标。本研究以长期受到砷污染胁迫并经历污染治理的阳宗海为研究对象,设置南、中、北3个调查位点,于2015年4月-2019年12月对浮游植物和水质因子开展季节调查和空间分析,通过识别浮游植物生物量的时空分布模式与驱动因子,评价了砷污染与治理下浮游植物生物量的变化机制和生态修复效果。调查结果显示,采样期间阳宗海浮游植物以蓝藻门为主,浮游植物的生物量范围为0.7~30.4 mg/L,平均生物量在2016年最低((3.0±1.8) mg/L)、在2017年最高((10.5±8.9) mg/L)。ANOVA分析结果显示,浮游植物生物量存在显著的季节差异而空间差异不明显。相关分析结果显示,阳宗海浮游植物生物量与砷浓度和透明度呈显著负相关,而与水体温度和pH呈显著正相关。多元线性回归分析进一步显示,砷和水温是驱动阳宗海浮游植物生物量变化的显著环境因子。由此可见,在重金属污染湖泊经过修复后,水体砷遗留物的毒性效应仍然对浮游植物生长产生了明显的抑制作用,表明了水体重金属污染物可能具有长期的沉积物释放作用与持久的生态毒理效应。  相似文献   

Geochemical characteristics of ores and surface waters for environmental risk assessment in the Pinpet iron deposit,southern Shan State,Myanmar     

Kyaw Zay Ya  Tsubasa Otake  Aoi Koide  Kenzo Sanematsu  Tsutomu Sato 《Resource Geology》2020,70(3):296-308

Mining operations in the Pinpet Fe deposit, which is the second‐largest Fe deposit in Myanmar, are currently suspended, in part because of possible contamination of heavy metals and hazardous elements (e.g., Fe, As, Cu, Zn, and U) into the surrounding aquatic environment and associated public concern. However, a scientific investigation of the source and degree of contamination in streams near the deposit has not yet been conducted. Therefore, we quantified heavy‐metal and hazardous‐element concentrations of stream waters and sediments in stream beds, and measured the speciation and concentration of these metals in deposit Fe ores using the sequential extraction method, to better understand the influence of mining activities on the surrounding environment. Geochemical results for Nan‐tank‐pauk stream and its tributaries indicate that the chemical compositions of their waters are controlled by carbonate bedrock and that no detectable contamination has occurred as a result of mining activity or hematite and limonite ore beneficiation processes in either the wet or dry seasons. All measured heavy‐metal and hazardous‐element concentrations were below the World Health Organization standards for drinking water and the proposed national drinking water quality standards in Myanmar. Bulk chemical compositions of stream‐bed and tailings dam sediments show that As, Zn, and Cu concentrations are similar to those in uncontaminated sediments. Results of bulk mineralogical and chemical analyses of ore samples reveal that some limonite ore samples contain substantial amounts of As (up to 2 wt%). However, sequential extraction results indicate that most (>90%) of the As in these As‐rich ores is hosted in insoluble fractions (e.g., crystalline Fe hydroxides and clays). Therefore, arsenic is unlikely to be released into the aquatic environment by interacting with water during ore beneficiation processes should the mine resume operations.  相似文献