OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1976 · 74 citations · 0 references
Natural SciencesEarth SciencesHydrologyEnvironmental ChemistryGeochemistryInorganic ChemistryAquatic BiogeochemistryAquatic ChemistryAqueous GeochemistryFreshwater BiogeochemistryLake EcologyWater ChemistryAcid Deposition EffectsChemical WeatheringIon Exchange MechanismsLake AcidificationLake BiogeochemistryPh DependencePh Effects On PrecipitationWater Alkalinity
Long-term deposition of acid precipitation (pH 4.0 to 4.4) on poorly buffered areas in southern Scandinavia and northeastern North America is apparently responsible for the acidification (to below pH 5) of soft-water lakes in these areas. Chemical weathering and ion-exchange processes in terrestrial watersheds appear inadequate to neutralize all of the incoming acid. Stream and lake waters thus are acidified and lose their bicarbonate buffer. Relatively few lakes have pH levels in the poorly buffered pH 5.5 to 6.0 region. Sulfate supplied by acid precipitation becomes the major anion. Concentrations of Al, Mn and several heavy metals are higher in acid lakes than in unaffected soft-water lakes, apparently due to enhanced mobilization of these elements in acidified areas.