Skip to content

Arsenic distribution, speciation and solubility in shallow groundwater of Owens Dry Lake, California

by Ji Hun Ryu, Suduan Gao, Randy A. Dahlgren, Robert A. Zierenberg
Geochimica et Cosmochimica Acta ()
Get full text at journal


Generation of dust particles from the Owens Lake playa creates a severe air pollution hazard in the western United States. Much of the dust produced from the dry lakebed is derived from salts formed by evaporation of saline groundwater that often contains high concentrations of dissolved arsenic (As). The objectives of this research were to study the spatial distribution of dissolved arsenic in the shallow groundwater, and to examine factors affecting arsenic solubility and speciation. Evapoconcentration, redox potential, pH, and mineral solubility were examined as factors regulating arsenic biogeochemistry. Dissolved arsenic concentrations ranged from 0.1 to 96 mg L-1 and showed a general increase from the shoreline to the center of the lakebed. Arsenic concentrations were strongly correlated to electrical conductivity (EC) and ??D suggesting that evapoconcentration is an important process regulating total As concentrations. Arsenite [As(III)] was the dominant form of inorganic arsenic at Eh values less than about - 170 mV while arsenate [As(V)] was predominant at higher Eh values. Organic arsenic was negligible (<0.21%) in all shallow groundwater samples. Dissolved arsenic concentrations do not appear to be strongly regulated by solid-phase reactions. Solid-phase arsenic concentrations generally ranged between 4.0 and 42.6 mg kg-1 and a maximum concentration range (20 to 40 mg kg-1) was reached as solution concentration increased up to 80 mg L-1, indicating minimal sorption and/or precipitation of arsenic. Chemical equilibrium modeling indicated that orpiment (As2S3) was the only solid phase with a positive saturation index (indicating over-saturation), but only at high arsenic and sulfide concentrations. The findings of this research are important for assessing the potential environmental impacts of elevated arsenic concentrations on dust mitigation efforts taking place at Owens Dry Lake. Copyright ?? 2002 Elsevier Science Ltd.

Cite this document (BETA)

Readership Statistics

39 Readers on Mendeley
by Discipline
44% Earth and Planetary Sciences
15% Chemistry
13% Agricultural and Biological Sciences
by Academic Status
28% Researcher
18% Student > Ph. D. Student
15% Professor > Associate Professor
by Country
8% United States
3% Spain
3% France

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Sign up & Download

Already have an account? Sign in