砷
沉积物
海湾
地下水砷污染
环境化学
水柱
地质学
地表水
环境科学
水文学(农业)
海洋学
化学
环境工程
地貌学
有机化学
岩土工程
作者
John Chételat,Michael Palmer,Katrina A. Paudyn,Heather E. Jamieson,Marc Amyot,Reed J. Harris,Raymond H. Hesslein,Nicolas Pelletier,Inés Peraza
标识
DOI:10.1016/j.jhazmat.2023.131230
摘要
Arsenic contamination from mining poses an environmental challenge due to the mobility of this redox-sensitive element. This study evaluated arsenic mobility in sediments of Yellowknife Bay (Canada), a large subarctic water body impacted by gold mining during the 20th century. Short-term measurements of arsenic flux from sediment, arsenic profiling of the water column and sediment porewater, and mass balance modelling were conducted to assess the importance of sediment as an arsenic source. Sediment arsenic fluxes were highly variable throughout Yellowknife Bay and ranged from - 65-1520 µg m-2 day-1. Elevated fluxes measured near the mine site were among the highest published for well-oxygenated lakes. Redox boundaries were typically 2-3 cm below the sediment surface as indicated by porewater profiles of iron, manganese, and arsenic, with arsenic maxima of 65-3220 µg L-1 predominately as arsenite. Sediment arsenic flux was positively related to its solid-phase concentration. Modelling indicated sediment was a principal source of arsenic to the water column. Adsorption and precipitation processes in the oxidizing environment of near-surface sediments did not effectively attenuate arsenic remobilized from contaminated sediments. Internal recycling of legacy arsenic between sediment and surface water will impede a return to background conditions in Yellowknife Bay for decades.
科研通智能强力驱动
Strongly Powered by AbleSci AI