Long-term changes in the water chemistry of subarctic lakes as a response to reduction of air pollution: case study in the Kola region, Russia
Abstract
Sixty years of air pollution from two Cu-Ni smelting plants ("Pechenganikel" and "Severonikel") in the Kola region in northwest Russia have posed a severe threat for water quality, specifically acidification, in subarctic lakes. In the last two decades, emissions of SO2, Cu and Ni from the smelters have declined with 33 %, 40 % and 36 %, respectively. 75 lakes in Kola Peninsula were sampled with 5-year intervals for the period 1990 to 2018 and analysed for major anions and cations, DOC and heavy metals, also strong and weak organic acids. The lakes were grouped according to geology and distance to emission sources . The most acid-sensitive lakes are located on granites, quartz sands or in highlands. Since 1990, ANC has increased, which is connected to the reduction of the contents strong acids in water (sulphate, chloride) while base cations concentrations have been almost unchanged. Despite the reduction of sulphate, concentrations of alkalinity have not increased in lake water. We have found an increase in concentration of dissolved organic carbon (DOC) and nutrients (specify which) in Kola lake waters over a 20-year period. We suggest that this phenomenon can be explained by two mechanisms: a reduction in deposition of strong acids and warming climate. Concentrations of Ni and Cu have decreased 5-10-fold over the last 20 years. We conclude that reduced emissions from Cu-Ni smelting plants has led to improved water quality in the Kola region.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMGC078..04D
- Keywords:
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- 1621 Cryospheric change;
- GLOBAL CHANGE;
- 1622 Earth system modeling;
- GLOBAL CHANGE;
- 1631 Land/atmosphere interactions;
- GLOBAL CHANGE;
- 1637 Regional climate change;
- GLOBAL CHANGE