Thallium diagenesis in lacustrine sediments

Geochemical and anthropogenic enrichments of Mo in sediments from perennially oxic and seasonally anoxic lakes in Eastern Canada

“…4e). It should be noted that low pH values (pH $5.7) preclude the formation of authigenic Mn oxyhydroxides in the sediments of this lake (Laforte et al, 2005).…”

Arsenic, iron and sulfur co-diagenesis in lake sediments

“…Our average measured As value of SLRS-4 was 3% lower than the certified value. We measured porewater RS ÀII , major cations and anions, DIC and DOC as described by Laforte et al (2005) and RS 0 by square-wave cathodic stripping voltammetry as described by Wang et al (1998). It should be noted that RS ÀII and RS 0 are defined as (Wang and Tessier, 2009):…”

“…The left-hand side of the reactions is expressed in terms of the MINEQL+ components As V O 4 3À , As III O 3 3À , S 0 ðaqÞ , H + and HS À . When required, the reactions were expressed in terms of S 0 aq using 1 / 8 S(a) 8(s) = S 0 ðaqÞ ; log K = À6.68 (Wang and Tessier, 2009 ues close to the sediment-water interface (pH 5.4-6.0) preclude the formation of Mn oxyhydroxides in the sediments of this lake (Laforte et al, 2005). Conversely, in the slightly alkaline Lake Du Syndicat (pH 7.2-7.9), the enriched As layer just below the sediment surface coincides with both a small Fe and a marked Mn enrichment (Fig.…”

Mercury transformations and fluxes in sediments of a riverine wetland

“…Sampling of peepers and the analytical methods for the measurement of pH and concentrations of dissolved Al, Ca, Fe, Mg, Mn, sulfide, SO 4 2À , and organic and inorganic C are described in detail elsewhere (Alfaro-De la Torre and Tessier, 2002;Laforte et al, 2005). Samples for RS(0) analysis were also collected from the peepers with N 2 -purged polypropylene syringes and injected through Teflon-lined septa into pre-weighted 5-mL amber glass vials containing 2 mL of ethanol, 0.4 mL of 1 M NaNO 3 , 40 lL of tetrahydrofuran, and 10 lL of 1 M HNO 3 added in a glove box under a N 2 atmosphere to minimize contamination with oxygen (Wang et al, 1998).…”