Abstract
The surficial sediments of Moira Lake average 545 μg.g −1 of arsenic, with maximum values close to 1 mg.g −1 at depths of 23–27 cm below the sediment water interface. The sediment porewater is the linking agent between the sediment solid phase and the overlying lake water. The depth distributions of total As in interstitial waters at all stations are characterized by subsurface maxima, with concentrations four to six times greater than in the lake wates. In all the porewater profiles examined, inorganic As [As(III)+As(V)] comprised most of the As. The As(III) (arsenite) percentage ranged from 66–83%. Methylated-As compounds represented <2% of the total As. The strong correlation of As with Fe and Mn together suggests that both Fe and Mn are involved in the As mobility. The elevated As concentrations in bottom sediments represent a continuous internal mining of As towards the interface all year around. The concentration gradient of total dissolved As indicates that an upward diffusion of As towards the water column with the estimated annual fluxes being 0.8–3.8 μg.cm −2.y −1.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
