Environmental status of Daya Bay surface sediments inferred from a sequential extraction technique

Acid-volatile sulfide and simultaneously extracted metals in surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea: Concentrations, spatial distributions and the indication of heavy metal pollution status

“…effects range-low (ERL) and effects range-mean (ERM) concentrations which are empirical approaches based on total metal concentrations (Long et al, 1995). The results cannot provide sufficient information and sometimes it may be misleading to use only total metal concentrations in sediments to assess the toxicity or the bioaccumulation ability of metals, because bioavailability of metals in sediments not only depends on their total concentrations but also on their chemical forms (Sahuquillo et al, 2003;Gao et al, 2008Gao et al, , 2010Gao and Chen, 2012;Gao and Li, 2012). Furthermore, any metal that is insoluble in the 1 M or 6 M HCl used in the AVS extraction is unlikely to be bioavailable, and therefore it is non-toxic (Allen et al, 1993;Di Toro et al, 2005).…”

Concentration and fractionation of trace metals in surface sediments of intertidal Bohai Bay, China

“…This scheme partitions elements into four operationallydefined geochemical fractions including: acid soluble, reducible, oxidisable and residual. The detailed sequential extraction protocol used in this study has been described elsewhere (Gao et al, 2008(Gao et al, , 2010.…”

Characterization of surface sediments from the Beijing-Hangzhou Grand Canal (Zaozhuang section), China: assessment of beryllium enrichment, biological effect, and mobility

“…A high-pressure wet acid digestion (HF, HNO 3 , and HClO 4 mixed at a volume ratio of 5:2:1) was employed to obtain the overall information of Be in surface sediments (Gao et al 2010). The geochemical morphological information of Be was obtained with the BCR sequential extraction procedure (Rauret et al 1999); this method divided the geochemical forms of heavy metals into four categories: acid-soluble fraction, reducible fraction, oxidizable fraction, and residual fraction, hereinafter abbreviated as F1, F2, F3, and F4.…”

“…Whether a metallic element in sediment can exchange with the overlying water depends on its existing forms in sediment. Different forms of metallic elements show different geochemical behaviors and bio-availability (Gao et al 2010;Zhang et al 2013). Only the forms with high mobility that have been re-released into the water through the complex, reduction and dissolution can become a crucial factor affecting the nutrition and pollution of waters (Tessier et al 1979).…”