Metal sediment

Phytostabilization Soils, sediments Metals and metalloids (As, Cd, Cr, Cu, Pb, Zn, U, Se) Hydrophobic organics (PAHs, PCBs, dioxins, furans, pentachlorophenol, DDT, dieldrin) Phreatophyte trees to transpire large amounts of water for hydraulic control Grasses with fibrous roots to stabilize soil erosion Dense root systems are needed to sorb/bind contaminants... 

Phytoextraction Soils, sediments Metals (Ag, Au, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Zn) Radionuclides (90Sr, 137Cs, 239Pu, 234JJ 238JJ) Sunflowers Indian mustard Rape seed plants Barley, hops Crucifers Serpentine plants Nettles, dandelions... 

Humus can form stable complexes such as chelates with polyvalent cations. SOM is capable of strong polydentate binding to transition metals in a chelate [17,19,45, 65-67]. The complexation of metal ions by SOM is extremely important in affecting the retention and mobility of metal contaminants in solid phases and waters [45]. Several different types of SOM/humus-metal reactions can occur (Fig. 11), and include reactions between DOC-metal ions, complexation reactions between SOM-metal ions, and bottom sediments-metal ions. The functional groups of SOM (Fig. 10) have different affinities for metal ions as shown below ... 

Metalliferous sediments Metal-rich sediments. Most are found around active spreading centers because hydrothermal activity is the primary source of the metals. 

Mathew, R., Wu, KB. and Santore, R.C. (2005) Predicting sediment metal toxicity using a sediment biotic ligand model methodology and initial application. Environ Toxicol Chem, 24,... 

O Reilly Wiese, S.B., Bubb, J.M. and Lester, J.N. (1995) The significance of sediment metal concentrations in two eroding Essex salt marshes. Marine Pollution Bulletin, 30(3), 190-99. 

Station Sediment (Metal- PAH-PCB- SEMtAVS) Porewater (TBT) Amphipod (Rhepox) (Survival- Avoidance) Amphipod (Eohaustorius) (Survival- Avoidance) Bivalve (Normal-Survival-Combined Normal Survival) Polychaete (Survival- Growth) Overall... 

Tack, F.M.G., Vossius, H.A.H. and Verloo, M.G. (1996) A comparison between sediment metal fractions, obtained from sequential extraction and estimated from single extractions. Int.J. Environ. Anal. Chem., 63, 61. 

Similar validation is conducted by some other regulatory authorities. For example, it was shown in an Australian study that there was no effect on sensitive species at concentrations 10 times above the EQS values for metals in sediments because of the EQS derivation method in which toxicity was equally ascribed to cooccurring chemicals (leading to concerns over the ecological realism of sediment metal EQS values) (Simpson et al. 2005). In Canada, no formal validation programs of this type have been undertaken. 

Three channels from Lake Pontchartrain, Louisiana, to the Gulf of Mexico were studied as sample (oysters, clams, and sediments) sources to determine trace element (Ag, As, Be, Cd, Cr, Cu, Hg, Ni, Pb, Se, Tl, and Zn) uptake only T1 was not detected in the tissue and it was minimally present in the three sediments [38]. Oysters in the Inner Harbor Navigation Canal contained high concentrations of Zn, whereas clams from the other two channels (i.e., the Rigolets and the Chef Menteur Pass) contained high levels of Cu. Sediment metal concentrations were reflected in the tissue levels. 

In order to understand chemically analyze the materials found at archaeological sites it is essential to understand something about their context - sources, technology, use, and disposal. In this chapter, we examine some of the more common raw materials at archaeological sites - rock, pottery, bone, sediments, metals, and other things like shell, pigments, charcoal, and plant remains (Fig. 3.1). There aie many other materials, generally less common, that we do not consider here. 

Weisberg SB, Wilson HT, HeimbuchDG, et al. 2000. Comparison of sediment metal Aluminum relationships between the eastern and Gulf coasts of the United States. Environ Monit Assess 61 373-385. 

SRM1646a Estuarine sediment - metals Certified values for 19 metals collected from Chesapeake Bay, MD, USA... 

Langston WJ., Bryan G.W., Burt G.R., Pope N.D. (1994) Effects of Sediment Metals on Estuarine Benthis Organisms, R D note 203. Bristol National Rivers Authority. 

Metal salts in the sediments Metals absorbed in sediment... 

Table I. Examples of the use of combined sediment metal and SCP data with catchment moss metal data to suggest sources of contaminants (abbreviated from Rose ct al., 1998b).

Sediment metal Moss metal Sediment SCP Suggested source... 

C. Rousseau, F. Baraud, L. Leleyter, O. Gil. Cathodic protection by zinc sacrificial anodes Impact on marine sediment metallic contamination. Journal of Hazardous Materials, Vol. 167, Nos. 1-3, pp. 953-958, 2009. 

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