Plants trace elements

Soil solution is the aqueous phase of soil. It is in the pore space of soils and includes soil water and soluble constituents, such as dissolved inorganic ions and dissolved organic solutes. Soil solution accommodates and nourishes many surface and solution reactions and soil processes, such as soil formation and decomposition of organic matter. Soil solution provides the source and a channel for movement and transport of nutrients and trace elements and regulates their bioavailability in soils to plants. Trace element uptake by organisms and transport in natural systems typically occurs through the solution phase (Traina and Laperche, 1999). 

Berrow M.L., Burridge J.C., Reith J.W.S. Soil drainage conditions and related plant trace element contents. J Sci Food Agric 1983 34 53-54. 

Johnson C.D., Vance G.F. Long-term land application of biosolids soil and plant trace element concentrations. University of Wyoming, Cooperative Extension Service, B-1062. 1998... 

Meslch, F. G. Schwltzgebel, K. "Coal Fired Power Plant Trace Element Study - A Three Station Comparison", Radian Corp., Austin, TX, Report No. TS-la, 1975. 

Many trace elements are present in coal ashes at concentration levels far in excess of average crustal values. Although new uses are being found for fly ashes, there remains an excess production that ends in lagoons, ash mounds and landfill sites. In the ashes produced in coal-fired power plants trace elements are present in minerals such as quartz, mullite and magnetite, but their overall contribution to the bulk is minimal. The trace elements present in the glass are quantitatively more important, but for the more volatile elements it is surface association that is particularly important, because this is the major location in the ash for some elements and they are potentially leachable. 

Coal-Fired Power Plant Trace Element Study, Report prepared for the... 

Health and Environment. Manganese in trace amounts is an essential element for both plants and animals and is among the trace elements least toxic to mammals including humans. Exposure to abnormally high concentrations of manganese, particulady in the form of dust and fumes, is, however, known to have resulted in adverse effects to humans (36,37) (see Mineral nutrients). 

Molybdenum, recognized as an essential trace element for plants, animals, and most bacteria, is present in a variety of metaHo enzymes (44—46). Indeed, the absence of Mo, and in particular its co-factor, in humans leads to severe debility or early death (47,48). Molybdenum in the diet has been impHcated as having a role in lowering the incidence of dental caries and in the prevention of certain cancers (49,50). To aid the growth of plants. Mo has been used as a fertilizer and as a coating for legume seeds (51,52) (see FERTILIZERS Mineral NUTRIENTS). 

Zinc, like most metals, is found in all natural waters and soils as well as the atmosphere and is an important trace element in plant and animal life (see Mineral nutrients). Rocks of various kinds contain 20—200 ppm zinc and normal soils 10—30 ppm (average ca 50 ppm) in uncontaminated areas. The average zinc content of coal is 33 ppm. Seawater contains 1—27 )-lg/L (median ca 8 p.g/L), and uncontaminated freshwater usually <10 / g/L. 

An average of about 7 ppm of bromine is found ia terrestrial plants, and edible foods contain up to 20 ppm. Among animals the highest bromide contents are found ia sea life, such as fish, sponges, and cmstaceans (44). Animal tissues contain 1—9 ppm of bromide and blood 5—15 ppm. The World Health Organization has set a maximum acceptable bromide iatake for humans at 1 mg/kg of body weight per day. In adult males the bromine content ia semm has been found to be 3.2—5.6 p.g/mL, ia urine 0.3—7.0 p.g/mL, and ia hair 1.1—49.0 p.g/mL. Bromine may be an essential trace element as are the other hahdes (45). 

In hospitals, chemical analysis is widely used to assist in the diagnosis of illness and in monitoring the condition of patients. In farming, the nature and level of fertiliser application is based upon information obtained by analysis of the soil to determine its content of the essential plant nutrients, nitrogen, phosphorus and potassium, and of the trace elements which are necessary for healthy plant growth. 

The examples discussed above suggest useful directions for future research involving trace element analysis of bones. Specifically, the effects of developmental age and other factors (e.g., porosity, mineralization) that may lead to differences in surface area of specimens should be considered. Diage-netic effects should be monitored by analysis of a suite of elements whose abundances are not controlled by dietary abundances (e.g., Mn, Zr, etc.). Finally, although alkaline elements such as Sr and Ba are most likely to reflect the Sr/Ca and Ba/Ca levels of the diet, omnivores such as humans are likely to obtain the majority of these elements from plants rather than from animals. Therefore for accmate diet reconstruction it is necessary to determine the total abundance of Ca as and the Sr/Ca and Ba/Ca ratios of the plant and animal resources that were potential dietary staples. The effects of culinary practices on elemental abundances (Burton and Wright 1995 Katzenberg et al. this volume) must also be evaluated. 

Jenkins DW. 1981. Biological monitoring of toxic trace elements, Vol 1, Biological monitoring and surveillance Vol 2, Toxic hace metals in plants and animals of the world, Parts I, II, and III. U.S. Environmental Protection Agency, Envhonmental Systems Laboratory EPA-600/S3-80-090. 

Quevauviller Ph, Maiee EA, Kramer KJM (1998b) Trace elements in aquatic plants (CRMs 60,... 

The literature includes a number of mis-matches, the following standing as examples for the many The use of bovine liver and other animal tissues for QC in the analysis of hmnan body fluids should not be considered by analysts. The matrix and the levels of trace elements do not match the levels to be analyzed, which may lead to serious errors. An even more severe mis-use was recently reported by Schuhma-cher et al. (1996) for NIST SRM 1577a Bovine Liver, which was used for QC in the analysis of trace elements in plant materials and soil samples in the vicinity of a municipal waste incinerator. Also recently, Cheung and Wong (1997) described how the quality control for the analysis of trace elements in clams (shellfish) and sediments was performed with the same material NIST SRM 1646, Estuarine sediment. Whilst the selected SRM was appropriate for sediments, its usefulness as a QC tool for clams is difficult to prove see also Chapter 8. This inappropriate use is the more mystifying because a broad selection of suitable shellfish RMs from various producers is available. 

Soil pH is easily tested for and determines the availability of nutrients and the success of white clover. Very acid soils (below pH 5.0) will cause a deficiency of the trace elements iron, boron, copper and molybdenum and conversely will cause injury to plant growth by increasing the availability of aluminium and manganese to toxic levels. Over-liming, on the other hand, which can raise the pH above 6.5, will reduce the availability of certain essential elements such as phosphorus, manganese and boron. 

Ecologically, copper is a trace element essential to many plants and animals. However, high levels of copper in soil can be directly toxic to certain soil microorganisms and can disrupt important microbial processes in soil, such as nitrogen and phosphorus cycling. Copper is typically found in the environment as a solid metal in soils and soil sediment in surface water. There is no evidence that biotransformation processes have a significant bearing on the fate and transport of copper in water. 

At many plants, fluxes are added to the metal to reduce hydrogen contamination, remove oxides, and eliminate undesirable trace elements. Solid fluxes such as hexachloroethane, aluminum chloride, and anhydrous magnesium chloride may be used, but it is more common to bubble gases such as chlorine, nitrogen, argon, helium, and mixtures of chlorine and inert gases through the molten metal. 

Possible causes of sludge bulking include (a) absence of certain necessary trace elements in wastewater (b) wide fluctuations in wastewater pH (c) limited DO in the aeration tank (d) inadequate FIM ratio (e) inadequate mean cell residence time Tc (f) inadequate return sludge pumping rate (g) internal plant overloading and (h) poor sedimentation clarifier operation. 

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