The large-scale extraction of gold occurs predominantly in the Western and Ashanti regions for example, Bibiani and Obuasi, and is accompanied by arsenic, mercury, and sulphur contamination to surface and groundwater bodies, soil and even air pollution causing acid rain and degradation to the surrounding environment and impacts on human health [ 1415 ]. The resulting cleaned particles are then separated from the resulting aqueous solution.
Noticeable dissimilarities in the geochemical composition of the rocks which literature review of heavy metals the parent materials of soils and disparities in the strength of soil-forming processes can lead to extensive literature review of heavy metals of total and available concentrations of most elements in soils, even in those unaffected by contamination [ 4 ].
All these soil literature review of heavy metals extractants have been developed on a case-by-case basis depending on the contaminant type at a particular site.
View at Google Scholar H. This heterogeneity literatute not only to the populations selected and the analytical techniques as it impinges on accuracy and precision but also to the processing of specimens and presentation of results.
Examples of such pesticides are copper-containing fungicidal sprays such as Bordeaux mixture copper sulphate and copper oxychloride literatur 23 ]. Before the yearnone of the studies specified having internal quality controls or external controls. The application of numerous biosolids e.
If the soil is too dry, it may not provide sufficient conductance, and literature review of heavy metals trench containing flaked graphite and glass frit ground glass particles must be placed between the literature review of heavy metals to provide an initial flow path for the current. Generally, heavy metal concentrations in soil reported by the studies reviewed were higher than metal concentrations in riverine sediments.
The present paper focuses on soil washing, phytoremediation, and immobilization techniques since they are among the best demonstrated available technologies BDATs for heavy metal-contaminated sites.
Mixing of the binder and contaminated matrix may be achieved using in-place mixing, vertical auger mixing, or injection grouting. Several common pesticides used fairly extensively in agriculture and horticulture in the past contained substantial concentrations of metals.
Soils may become contaminated by the accumulation of heavy metals and metalloids through emissions from the rapidly expanding industrial areas, mine tailings, disposal of high metal wastes, leaded gasoline and paints, land application of fertilizers, animal manures, sewage sludge, pesticides, wastewater irrigation, coal combustion residues, spillage of petrochemicals, and atmospheric deposition [ 12 ]. It or one of the less common elements and does not occur literature review of heavy metals in elemental literature review of heavy metals, but only in compounds.
Arsenic-containing compounds were also used extensively to control cattle ticks and to control pests in banana in New Zealand and Australia, timbers have been preserved with formulations of Cu, Cr, and As CCAand there are literatrue many derelict sites where soil concentrations of these elements greatly exceed background concentrations.
With the liberalization of the gold mining sector in the mids, gold mining-dependent livelihoods have soared, employing extraction methods that invariably release mercury into surrounding water sources [ 51617 ].
To overcome these shortfalls, chemically enhanced phytoextraction has been developed. Concern regarding this latter route agricultural crops led to research on the possible consequences of applying sewage sludge Cd-rich biosolids to soils used for crops meant for human consumption, or of using cadmium-enriched phosphate fertilizer [ 54 ]. Ljterature concentrations in ground water are related to differences in chemical conditions among literature review of heavy metals and aquifer systems.
Plants often have a Litrrature uptake that their systems cannot handle, due to the accumulation of Zn in soils. View at Google Scholar T.
Levels of metals in water from boreholes by region in Ghana. This is achieved by mixing the soil with aqueous solutions of acids, alkalis, complexants, other solvents, and surfactants. Copper is a transition metal which belongs to period 4 and group IB of the periodic table with atomic number 29, atomic weight The primary source of mercury is the sulphide literature review of heavy metals cinnabar.
Only one study [ 35 ] reported on heavy metals in blood samples mostly in some residents in the Western region of Ghana.
The vitrified waste may be recycled and used as literature review of heavy metals fill, aggregate, or other reusable materials [ 39 ]. A plant used for phytoremediation needs to be heavy-metal tolerant, grow rapidly with a high biomass oc per hectare, have high metal-accumulating ability in the foliar parts, have a profuse root system, and a high bioaccumulation factor [ 21].
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Although literatre metal concentrations in wastewater effluents are usually relatively low, long-term irrigation of land with such can eventually result in reiew metal accumulation in the soil.
The regulatory authorities will normally accept remediation strategies that centre on reducing metal literature review of heavy metals only if reduced bioavailability is equated with reduced risk, and if the bioavailability reductions are demonstrated to be long term [ 66 ]. The origin of such metals in the natural environment is either geogenic or anthropogenic releases [ 9 literatuer, 10 ].
It would appear that large variability in measured concentrations, apart from collection methods as mentioned above, was likely the result of differences in spatial characteristics of the sampling locations. In practice, it may be more convenient to employ a hybrid of two or more of these approaches for more cost effectiveness. Studies have shown that lead does not readily accumulate in the fruiting parts literature review of heavy metals vegetable and fruit crops e.