RT journal article
T1 Trace metals partitioning among different sedimentary mineral phases and the deposit-feeding polychaete Armandia brevis
A1 Huerta-Díaz, Miguel Ángel
A1 Delgadillo-Hinojosa, Francisco
A1 Hare, Landis
A1 Siqueiros-Valencia, Arturo
A1 Díaz de Alba, Margarita Isabel
A1 Galindo Riaño, María Dolores
A2 Química Analítica
K1 Speciation
K1 Trace metal
K1 Sediment contamination
K1 pyrite
K1 armandia brevis
AB Trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) were determined in two operationally defined fractions (HCl and pyrite) in sediments from Ensenada and El Sauzal harbors (Mexico). The HCl fraction had significantly higher metal concentrations relative to the pyrite fraction in both harbors, underlining the weak tendency of most trace metals to associate with pyrite. Exceptionally, Cu was highly pyritized, with degrees of trace metal pyritization (DTMP) N80% in both harbors. Dissolved Fe flux measurements combinedwith solid phase Fe sulfide data indicated that 98 mt of Fe are precipitated as iron sulfides every year in Ensenada Harbor. These Fe sulfides (and associated trace metals) will remain preserved in the sediments, unless they are perturbed by dredging or sediment resuspension. Calculations indicate that dredging activities could export to the open ocean 0.20±0.13 to (0.30 ± 0.56) × 103 mt of Cd and Cu, respectively, creating a potential threat to marine benthic organisms. Degrees of pyritization (DOP) values in Ensenada and El Sauzal harborswere relatively low(b25%)while degrees of sulfidization (DOS)were high (~50%) because of the contribution of acid volatile sulfide. DOP values correlated with DTMP values (p ≤ 0.001), indicating that metals are gradually incorporated into pyrite as this mineral is formed. Significant correlations were also found between DTMP values and −log(Ksp(MeS)/Ksp(pyr)) for both harbors, indicating that incorporation of trace metals into the pyrite phase is a function of the solubility product of the corresponding metal sulfide. The order in which elements were pyritized in both harbors was Zn ≈ Mn b Fe b Cd ≈ Pb b Ni ≈ Co b bCu. Lastly, a strong correlation (r2= 0.87, p b 0.01) was found between average reactive trace metal concentrations and metal concentrations measured in Armandia brevis (a deposit feeding Opheliid polychaete), suggesting that these labile sedimentary metals are preferentially accumulated by the polychaete, making it a useful biomonitor of sedimentary metal exposure.
PB Elsevier
YR 2016
FD 2016
LK http://hdl.handle.net/10498/20456
UL http://hdl.handle.net/10498/20456
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 13-nov-2026