Lake sediment

Provide an SOP for the determination of cadmium in lake sediments by atomic absorption spectrophotometry using a normal calibration curve. 

Air. Studies have shown that 2500 years ago lead pollution caused by Greek and Roman silver smelters was a significant problem (4). Based on analysis of lake sediments and Greenland s ice, it was found that lead contamination from smelters in southern and central Europe was carried throughout the northern hemisphere. As long ago as the thirteenth century, air pollution has been linked to the burning of coal (4). The main concern was the smell from the sulfur in the coal and the effects of the soot. It was not until many years later that the effects of air pollution on people s health were discovered. 

Humans may also be indirectly affected through exposure to increased levels of toxic metals in drinking water and food. Increased levels of toxic metal are a consequence of direct deposition of pollutants into water sources, increased leaching of metal from soils and lake sediments, and increased corrosion of water pipes. 

Shukla, S.S. Kyers, J.K. Armstrong, D.E. Arsenic Interference in the Determination of Inorganic Phosphate in Lake Sediments. J. Environ. Quality, 1972, 1, 292-295. 

Koyama, T. (1963). Gaseous metabolism in lake sediments and paddy soils and the production of atmospheric methane and hydrogen, /. Geophys. Res. 68, 3971-3973. 

Emerson, S. and Widmer, G. (1978). Early diagenesis in anaerobic lake sediments II. Equilibrium and kinetic factors controlling the formation of iron phosphate. Geochim. Cosmochim. Acta 42,1307-1316. 

Takamatsu, T., Kawashima, M. and Koyama, M. (1985). The role of Mn-rich hydrous manganese oxide in the accumulation of arsenic in lake sediments. Water Res. 19,1029-1032. 

N02 did not accumulate in lake sediments under conditions where nitrate rapidly disappeared. The low levels of both nitrite and nitrosatable amines in natural waters, along with expected third order kinetics fc make extensive nitrosamine formation unlikely. The prospect has been discussed by Dressel. ... 

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

The anaerobic dechlorination of PCBs has been extensively studied both in microcosms and in field samples from heavily contaminated sites in the United States. Three main patterns have been fonnd—N that removed flanked meto-chlorines, P that removed para-chlorines, and LP that removed nnflanked para-chlorines (Bedard et al. 1998). By contrast, ort/to-chlorines were more recalcitrant. These experiments, which have been discussed in Chapter 9, Part 2, laid the fonndation for analysis of a field situation and an appreciation of the effect of long-term exposnre of contaminated lake sediment (Magar et al. 2005a,b). Substantial dechlorination took place in buried sediment cores (35-40 cm) compared with the snrface sediment cores (0-5 cm). Although there were some variations among the cores, the di- and trichlorinated biphenyls were produced at the expense of the... 

Stern GA, MD Loewen, BM Miskimmin, DCG Muir, JB Westmore (1996) Characterization of two major toxaphene components in treated lake sediment. Environ Sci Technol 30 2251-2258. 

Appleby PG. 2001. Chronostratigraphic techniques in recent sediments. In Last WM, Smol JP, editors. Tracking environmental change using lake sediments. Vol. 1 Basin analysis, coring, and chronological techniques. Dordrecht, the Netherlands Kluwer Academic Publishers, p. 171-203. 

Brndler R, Renberg I, Appleby PG, Anderson NJ, Rose NL. 2001. Mercury accumulation rates and spatial patterns in lake sediments from west Greenland a coast to ice margin transect. Environ Sci Technol 35 1736-1741. 

Engstrom DR, Polhnan CD, Fitzgerald WF, Balcom PH. 2003. Evaluation of recent trends in atmospheric mercury deposition in south florida from lake-sediment records. Tallahassee (FL) Florida Department of Environmental Protection, 27 pp. 

Lockhart WL, Wilkinson P, Billeck BN, Danell RA, Hunt RV, Brunskill GJ, DeLaronde J, St. Louis V. 1998. Fluxes of mercury to lake sediments in central and northern Canada inferred from dated sediment cores. Biogeochemistry 40 163-173. 

Marine sediments, estuarine sediments, freshwater pond sediments, harbour sediments, stream sediments, lake sediments... 

Marine sediments, plant, flesh water lake sediment soil terrestrial plants milk powder Freshwater sediment soil Spruce twigs needles River sediment Coal fly ash... 

As an example, imagine a carbonate-rich sediment that contains a small but significant fraction of detrital silicate. The sediment might be a lake sediment, a surface coral, a deep-sea coral, a carbonate-rich bank sediment, or a speleothem (see for example, Richards and Dorale 2003). The carbonate has a very high U/ Th ratio (on the order of 10" by atom) and the detrital material has a lower %/ Th ratio of about 10°. The carbonate and detrital materials each have specific values that differ from each... 

Olley JM, Roberts RG, Murray AS (1997) A novel method for determining residence times of river and lake sediments based on disequilibriiun in the thorium decay series. Water Resom Res 33 1319-1326 Onac BP, Lauritzen S-E (1996) The climate of the last 150,000 years recorded in speleothems preliminary results from north-western Romania. Theor Appl Karstology 9 9-21 O Neil JR., Clayton RN, Mayeda TK (1969) Oxygen isotope fractionation in divalent metal carbonates. J ChemPhys 51 5547-5558... 

Evans RD, Rigler FH. 1985. Long distance transport of anthropogenic lead as measured by lake sediments. Water Air Soil Pollut 24 141-151. 

Twelve distribution compartments are distinguished air, rivers, freshwater lakes, freshwater lake sediments, salt lakes, salt lake sediments, natural, agricultural and urban soil, groundwater, sea water, and sea water sediments. In contrast... 

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