Distribution in Sediment

Chiral pollutants in water remain in dynamic equilibrium with the sediment in a particular water body. Therefore, the presence of chiral pollutants in sediment is a natural situation. The concentration of these pollutants in the sediment depends on the various environmental factors and the adsorption capacity of the sediment itself. Vetter et al. detected two major compounds of technical toxaphene in Canadian lake sediment [63], and chloroborane congeners in the sediment from a toxaphene-treated Yukon lake [64], The authors analysed sediment samples collected over almost 60 years, from 1935 to 1992. The results are given in Table 2.3, which 

Wong et al. [67] measured the enantiomeric ratios for eight polychlorinated biphenyl enantiomers in aquatic sediments from selected sites throughout the United States. Nonracemic enantiomeric ratios (ERs) for PCBs 91, 95, 132, 136, 149, 174 and 176 have been found in sediment cores from Lake Hartwell. Nonracemic ERs for many of the enantiomers have also been found in riverbed sediment samples from the Hudson and Housatonic Rivers. Patterns in enantiomeric ratios among congeners were consistent with known reductive dechlorination patterns in both river sediment basins. The enantioselectivity of PCB 91 was found to be reversed between the Hudson and Housatonic River sites. Moisey et al. [24] determined the concentrations of a-, and y-hexachlorocyclohexane isomers 

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Ferguson et al. [18] reported on the application of a mixed-mode HPLC separation, coupled with ESI-MS for the comprehensive analysis of NPEOs and nonylphenol (NP) concentrations and distributions in sediment and sewage samples. The mixed-mode separation, which operates with both size-exclusion and reversed-phase mechanisms, allows the resolution of NPEO ethoxymers prior to introduction to... 

Wade TL, Atlas EL, Brooks JM, et al. 1988. NOAA Gulf of Mexico status and trends program Trace organic contaminant distribution in sediments and oysters. Estuaries 11 (3) 171-179. 

Stewart CC, Pinckney J, Piceno Y, Lovell CR (1992) Bacterial Numbers and Activity, Microalgal Biomass and Productivity, and Meiofaunal Distribution in Sediments Naturally Contaminated with Biogenic Bromophenols. Mar Ecol Prog Ser 90 61... 

Leoni, L. and Sartori, F. (1997) Heavy metal and arsenic distributions in sediments of the Elba-Argentario basin, southern Tuscany, Italy. Environmental Geology, 32(2), 83-92. 

Kim, S.K., Lee, D.S., Oh, J.R., Kahng, S.H., 2000a. Effects of extreme tidal range on characteristics of polychlorinated biphenyl distribution in sediment of industrial Incheon North Harbor, Korea. Environ. Toxicol. Chem. 19, 2448-2456. 

Figure 1. Methylated 1-methyl-1 -(4,8,12-trimethyl tridecyl)chromans (MTTC) as indicators of palaeosalinity structures, definition of the MTTC ratio and typical methylated MTTC distributions in sediments and petroleums. Description of the samples is given elsewhere (16).

Steward, C.C., Pinckney, J., Piceno, Y., and Lovell, C.R., Bacterial numbers and activity, microalgal biomass and productivity, and meiofaunal distribution in sediments naturally contaminated with biogenic bromophenols, Mar. Ecol. Prog. Ser., 90, 61, 1992. 

Since terrestrial actinomycetes have been such prolific producers of bioactive molecules, it was natural to investigate marine species of the same group. Therefore, it was no surprise that actinomycetes isolated from the marine sediments have proven to be one of the most prolific sources of bioactive secondary compounds.6-7 Their distribution in sediments varies depending on the depth from which the sample was collected. In several studies, Streptomyces predominated in near-shore marine sediments, but decreased dramatically past the sublittoral zone. In contrast, actinoplanetes are found in greater numbers as the distance from the shoreline increases. 

FeS2 distribution in sediments is primarily controlled by (1) sedimentation of detrital FeS2, (2) FeS2 oxidation in the upper root zone, and (3) FeS2 formation at the interface between suboxic and anoxic zones. 

Mackin, J.E., and Aller, R.C. (1986) The effects of clay mineral reactions on dissolved A1 distributions in sediments and waters of the Amazon continental shelf. Cont. Shelf Res. 6, 245-262. 

R. P. Gambrell, R. D. DeLaune, W. H. Patrick Jr., A. Jugsujinda, Mercury distribution in sediment profiles of six Louisiana lakes, J. Environ. Sci. Health, Pt A Toxic/ Hazard. Substances Environ. Engng, A36 (2001), 661-676. 

Figure 3. Average rare earth element (REE) distributions in sediments from...

Mackin, J. E., R. C. Aller, and W. J. Ullman. 1988. "The effects of iron reduction and nonsteady-state diagenesis on iodine, ammonium, and boron distributions in sediments from the Amazon continental shelf." Continental Shelf Research 8, 363-386. 

It is often said that hopanoids are the most abundant natural products on Earth (Ourisson and Albrecht, 1992) and a major body of work exists on their distributions in sediments, in prokaryotes and in plants. Most commonly, hopanoids are found in select groups of Bacteria, all of which are aerobic (Farrimond et al., 1998 Rohmer et al., 1984). In fact. 

B. Cosma, F. Soggia, M. L. Abelmoschi, R. Frache, Trace metals distribution in sediments from Terra Nova Bay - Ross Sea, Antarctica, Intern. J. Environ. Anal. Chem., 55 (1994), 121-128. 

R. O. Hallberg, Diagenetic and environmental effects on heavy metal distribution in sediments a hypothesis with an illustration from the Baltic Sea. 305-316, A. Kent, F. T. Manheim (Eds.), Dynamic Environmental Ocean Floor, 1982, Fanning-Lexington books, Lexington, Massachusetts. 

Finally, a recent approach to the study of trace metal distribution in sediment depth profiles deserves mention. This is a factor-analysis technique which is used to determine the main environmental condition prevailing at the place and time when the sediment was deposited, or the main process responsible for modification of the sediment after deposition (Buckley et al, 1995). The study in Halifax Harbour, Nova Scotia, (Buckley et al, 1995), established the following groups ... 

Aston, S.R., Assinder, DJ., Stanners, D.A. Rae, J.E. (1981) Plutonium occurrence and phase distribution in sediments of the Wyre estuary, north-west England. Marine Pollution Bulletin 12, 308-14. 

The concentrations of tetrabutyl tin range from 130 pg/kg TOC at sample site B to 14 pg/kg TOC at sample sites E and F and is below the LOQ at sample site D. The emission of this well known Elbe-specific compound was formerly linked to an industrial point source situated near the confluence of the Mulde and the Elbe rivers (Wilken et al., 1994, Schwarzbauer, 1997). Mono- and disubstituted chloronaphthalenes were also detected with concentrations between the LOQ at sample sites not influenced by Elbe derived contaminations and 70 and 100 pg/kg TOC at sample site B. These low chlorinated naphthalenes occur in the sediments with patterns similar to those of technical agents (e.g. Halowax 1000) and were formerly identified with comparable isomer distributions in sediments of the Elbe river and its tributaries (Schwarzbauer 1997, Schwarzbauer et al. 2001). On the contraiy the origin of the Elbe specific contaminant 4,4 -d ic h Iorodiphcnylsul tidc detected at sample sites A,B,C,E and F with concentrations ranging from 7 to 45 pg/kg TOC is still unknown. 

Generally, five types of elements have been distinguished according to their distribution in sediment cores from Lake Erie (Kemp et al., 1976) (i) Diagenetically mobile elements such as Fe, Mn and sulfur (ii) carbonate elements, carbonate-c and calcium (iii) nutrient elements, organic C, H, and P (iv) enriched elements, such as Cu, Cd, Zn Pb, and Hg and (v) conservative elements, e.g. Si, K, Ti, Na, and Mg. Comparison of group (iv) elements of environment concern with "conservative" elements (v) seem to be particularly useful for the reduction of grain size effects, since no separation step is required. 

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