Distribution and bioavailability of metals in soils in the vicinity of a copper works in Staffordshire, UK

Arsenic and copper fractionation was studied in contaminated soil and mine waste materials from a mining site in Devon, UK. Ten soil samples with Cu concentrations ranging from 300 -6144 mgykg and As concentrations ranging from 5512 -39715 mgykg were sequentially extracted using the modified method of Tessier et al. (1979) and Wenzel et al. (2001). The Classical Tessier et al. (1979) scheme was shown to be inadequate for studying either Cu or As fractionation as it severely underestimated the Feoxide associated fraction. The Modified Tessier et al. (1979) scheme, including the two additional steps specifically targeting Fe-oxides, was shown adequate for both Cu and As fractionation; however the Wenzel et al. (2001) protocol allows the prediction of changes in lability of As in various solid phases as a result of soil remediation or alteration in environmental factors. In agreement with other studies, arsenic was found to be held predominantly in the amorphous Fe-oxide fraction (55% -94%), which can be potentially mobilised with a change in redox conditions. A significant proportion of As can also be remobilised from the soils through the process of anion exchange. Copper presented a different fractionation pattern as it was distributed mainly between the organicysulfide and the Fe -Mn oxide fractions. Although the total concentrations of Cu in the soils are much lower than As, Cu appears to be solubilised to a much greater extent as indicated by the higher percentage contribution of Cu in the easily mobilisable fractions.

Section: Comparison Of the Classical And The Modified Tessier Schemessupporting

confidence: 60%

mentioning

confidence: 99%

Operationally defined associations of arsenic and copper from soil and mine waste in south-west England

Dybowska

Farago

Valsami‐Jones

et al. 2005

“…b Correlation significant at the 0.01 level (2-tailed). Mehra et al, 1999) justifying the use of total metal concentrations in soils as an important preliminary indicator of areas at risk from metal excess or deficiency (Berrow and Ure, 1985). Table 3 shows that the percentage of Cu extracted by water (mean ¼ 1.24%) is markedly lower than that extracted by EDTA (mean ¼ 56.45%) and acetic acid (mean ¼ 57.12%) .…”

Section: Cu Conc (Mg/kg)mentioning

confidence: 99%

Bioavailability of copper within Dolfrwynog Bog soils, North Wales, UK

Brewin

Mehra

Lynch

et al. 2007

Self Cite

Many studies have been reported in literature on the copper impregnated Dolfrwynog Bog and its flora, in particular the Cu-tolerant Armeria maritima. This paper investigates the bioavailability of Cu from the Bog soils using single and sequential extraction techniques for a number of specific sites. The Bog is enriched with Cu (concentrations in excess of 6,000 mgykg). However, comparing with earlier studies on the Bog, Cu concentrations appear to have decreased markedly over time. This may be attributed to a decrease in the organic matter content of soils and subsequent loss of Cu by leaching into stream waters. Single extractions with deionised water show that the Cu is not readily bioavailable, however, EDTA and acetic acid extracted in excess of 50% of the total Cu showing that that there is potential for Cu to be bioavailable. Cu is predominantly associated with the organic fraction of soils as shown by EDTA and sequential extractions. Although the average percentage bioavailabilty of Cu in the Bog has not altered over time, the amount of Cu present in the Bog has decreased substantially, hence the amount of Cu available for uptake by vegetation has also decreased and this may alter the nature of the Bog in the future. Results also show that the Bog is not homogenous in nature and that Cu concentrations and bioavailability vary spatially.

“…This is similar to the previous results (Li and Thornton, 2001;Chaudhary and Banerjee, 2004;Ogundiran and Osibanjo, 2009;Luo et al, 2012b) Cd and Pb are known to be preferentially associated with carbonate minerals, due to their similar size to the Ca ion (Rimstidt et al, 1998), thus a substantial proportion of Cd and Pb in various soils is usually associated with carbonates in the soils (Han and Banin, 1997;Maskall and Thornton, 1997;Faiga et al, 2011;Hu et al, 2011). On the other hand, soil organic matter fixes Cu very strongly (Bloom, 1981), thus a substantial proportion of Cu in various soils is often associated with soil organic matter (Han and Banin, 1997;Mehra et al, 1999;Lin et al, 2008b;Osakwe et al, 2012). In the urban soils in Nanjing (China), about 92.9% of Cr and 60.0% of Zn were associated with RES fractions (Lu et al, 2003), similar to the results found in this study.…”

Section: Chemical Forms Of Heavy Metals In the Soilmentioning

confidence: 99%

Concentrations and chemical forms of heavy metals in agricultural soil near the world’s largest and oldest tungsten mine located in China

Shao

Cheng

Duan

et al. 2013

Tungsten (W) mining has taken place in Ganzhou in China for about 100 years. Such long-term W mining may release large amount of metals to soils and waters around these mines. Twenty soil samples were taken from the area around the W mines and 10 soil samples from an area much farther away. These soil samples were analysed for physicochemical properties, heavy metal content and their chemical forms. Results show that long-term W mining significantly increased both total and labile contents of Cd, Cu, Pb and Zn, but did not, or only slightly, increased the total content of Co, Cr and Ni in the soil near the mine. Average enrichment factor (EF) in the agricultural soils was 4.0, 2.4, 2.2, and 2.0 for Cd, Cu, Pb and Zn, respectively. The labile fraction was dominated by the carbonate-bound fraction for Cd (54.5%) and organic matter-bound fraction for Cu (37.9%), while the major labile fractions for Pb and Zn were associated with carbonates (30.2% and 6.4%), oxides (17.9% and 10.6%) and organic matter (9.2% and 18.8%). Consequently, there is a need to be cautious about Cd in the soils contaminated by W mining.