Mercury sediments

Degetto S, Schintu M, Contu A, Sbrignadello G (1997) Santa Gilla lagoon (Italy) a mercury sediment pollution case study. Contamination assessment and restoration of the site. Sci Total Environ 204 49-56... 

Table 3.2 Results of PEC/PNEC evaluation of PCP and mercury sediments. ...

Mercury. Sediment samples were digested with a strong acid-per-... 

Simula, H. M. Lodenius, 1982. Recent increase in mercury sedimentation in a forest lake attributable to peatland drainage. Bull. Envir. Contam. Toxicol. 29 298-305. 

There are many types of water pollutants coming either from point sources such as sewage and industrial waste or from nonpoint sources such as agricultural runoff and storm water drainage. Water impairment includes excess levels of nutrients, metals (primarily mercury), sediment and organic enrichment due to agricultural activities, industrial and municipal discharges, atmospheric deposition, and unknown specific sources. More recently, pharmaceuticals and personal care products have been detected in U.S. waters at low concentrations. 

Grind 5 g mercury(I) nitrate dihydrate with 100 ml water in a mortar and tranfer it to a storage vessel along with the sediment the supernatant is fit for use as long as the sediment remains white [1],... 

Kinkead, J.D. Hamdy, Y. Trends in the Mercury Content of Western Lake Erie Fish and Sediment, 1970-1977 Ontario Ministry of the Environment, Toronto, Ontario, 1978, 19p. 

Kennedy, E.J. Ruch, R.R. Shimp, N.F. Distribution of Mercury in Unconsolidated Sediments From Southern Lake Michigan. Environ. Geo. 1971 Notes 44. 

Syers, J.K. Iskandar, I.K. Keeney, D.R. Distribution and Background Levels of Mercury in Sediment Cores from Selected Wisconsin Lakes. Water Air Soil Pollut. 1973 2, 105-118. 

In the profiles of the core from the industrial area, mercury displays the highest accumulation. Mercury in this area, close to the industrial district, has probably derived from a large chloralkali plant which has employed mercury cathodes since the fifties. Whereas, at present, very severe measures are taken to prevent mercury spills into the Lagoon, in the past, polluted waters and solid materials were discharged almost untreated. In the most superficial strata a marked decrease in the accumulations is, in fact, recorded. Lead and Cd accumulations are lower here by a factor of 5-10. The presence of cadmium in the sediments of the Lagoon has been referred to sphalerite (ZnS) processing on the basis of a strict concomitant... 

Volatilization is also a dominant transport mode for mercury, which is the most volatile metal in its elemental state. As with lead, a key reaction that can increase the volatility of mercury is formation of an organometallic compound. In this case, the reactions take place in water and are primarily biological, being mediated by bacteria commonly found in the upper levels of sediments. These reactions and their importance in the global mercury cycle are discussed in some detail later in the chapter. 

The widespread use of many metals such as silver, cadmium, copper, mercury, nickel, lead, and zinc has resulted in their accumulation in the environment. Sediments are often the repositories of toxic metals (e.g.. Table 15-2). For example, copper is used as an anti-biofouling agent in marine paints and many harbor sediments contain markedly elevated levels of copper. 

The average residence times for mercury in the atmosphere, terrestrial soils, oceans, and oceanic sediments are approximately 1 yr, 1000 yr, 3200 yr, and 2.5 x 10 yr, respectively. (See Bergan et al. (1999) for more details on atmospheric residence times.)... 

Thus, both elemental mercury and the mineral form cinnabar (HgS) can release Hg++, the mercuric ion. Bacteria can then methylate it to form sequentially CH3 Hg+, the methyl mercuric cation, and dimethyl mercury. The latter, like elemental mercury, is volatile and tends to pass into the atmosphere when formed. The methylation of mercury can be accomplished in the environment by bacteria, notably in sediments. 

Methyl arsenic, like methyl mercury, is generated from inorganic forms of the element by methylation reactions in soils and sediments. However, the mechanism is evidently different from that for mercury, depending on the attack by a methyl car-bonium ion rather than a methyl carbanion (Craig 1986, Crosby 1998). Methylation... 

Fleming EJ, EE Mack, PG Green, DC Nelson (2006) Mercury methylation from unexpected sources molybdate-inhibited freshwater sediments and an iron-reducing bacterium. Appl Environ Microbiol 72 457-464. 

King JK, JE Kostka, ME Frischer, FM Saunders (2000) Sulfate-reducing bacteria methylate mercury at variable rates in pure culture and in marine sediments. Appl Environ Microbiol 66 2430-2437. 

Pak K-R, R Bartha (1998) Mercury methylation and demethylation in anoxic lake sediments by strictly anaerobic bacteria. Appl Environ Microbiol 64 1013-1017. 

Kamman NC, Lorey PM, Driscoll CT, Estabrook R, Major A, Pientka B, Glassford E. 2003. Assessment of mercury in waters, sediments, and biota of New Hampshire and Vermont lakes, USA, sampled using a geographically randomized design. Environ Toxicol Chem 23 1172-1186. 

Munthe J, Hultberg H, Lee Y-H, Parkman H, I verfeldt A, Renberg I. 1995a. Trends of mercury and methylmercury in deposition, run-off water and sediments in relation to experimental manipulations and acidification. Water Air Soil PoUut 85(2) 743-748. 

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