Determination of heavy metal distribution in marine sediments

Heavy metal sources and associated risk in response to agricultural intensification in the estuarine sediments of Chaohu Lake Valley, East China

“…Thus, the results of the present study indicate that Cd, Pb and Zn in the estuarine sediments of the agricultural region of Chaohu Lake Valley had anthropogenic origins, while Cr, Cu and Ni were derived from the crust. These results could be interpreted as the contamination of Chaohu Lake Valley with Cd, Pb and Zn, which was not unexpected [10,39,40]. Although EF alone cannot precisely distinguish the sources of the heavy metals in the sediments, these factors may be useful indicators of the role of anthropogenic processes in their distribution.…”

The role of sediments in the chemistry of aquatic systems - Proceedings of the sediment chemistry workshop, February 8-12, 1982

“…Despite this, Jenne and others (1980) recommend the use of distilled water, and appear to have carried out successful sizing procedures for subsequent chemical analysis. Pilkington and Warren (1979) have had success using acetone as a settling medium. If little or no inorganic constituents are held as adsorbates or in ion exchange sites (Forstner and Wittmann, 1979), the ionic strength of the settling medium could be insignificant.…”

“…Conceptually, particles could be separated according to size and mineralogy either instrumentally (e.g., by magnetic separators, heavy mineral flotations) or manually (picking out mineral grains with the aid of a microscope) prior to chemical analysis (Francis and Brinkley, 1976; Pilkington and Warren, 1979). A physical separation alone, however, would not enable identification of phases attached to the particles such as hydrous Fe and Mn oxides and organic coatings.…”

“…By current practice, some physical separation techniques may alter the sample chemistry, and some are very time consuming. In addition, it is virtually impossible to physically separate the individual mineral grains in the finer size ranges, such as the clay minerals (Pilkington and Warren, 1979).…”

“…Individual constituents may be associated with several phases (interstitial water, clays, sulfides, carbonates, humic acids, pyroclastics, and others). Partitioning by phases or sites has been attempted by and by Pilkington and Warren (1979).…”