Fractionation of heavy metals in contaminated soils surrounding non-ferrous metals smelting area in the North China Plain

Abstract

The accumulation of heavy metals in soil is a serious environmental problem. The risk of metals in soil is associated critically with their species. Operationally determined speciation analysis of Cr, Mn, Ni, Cu, Zn, Sb, Cd and Pb was carried out in the area of non-ferrous metals-smelting in the North China Plain, using inductively coupled plasma-mass spectroscopy after sequential chemical extraction. The average potential mobility fraction was calculated. The average potential mobility of the metals had the following order: Cd(44.7%) > Pb(29.6%) > Mn(14.8%) > Zn(12.5%) > Cu(5.9%) > Sb(5.0%) > Ni(2.1%) > Cr(0.8%). It is concluded that there is a distinct spatial heterogeneity in the concentration of heavy metals in the studied area.The results indicate that the polluting heavy metals, in particular Cd and Pb, have high potential mobility.

Trace metals distribution in different geochemical phases of soils around automobile junk markets in southern Nigeria

“…This is consistent with the findings of Ramos et al, (1994); Ogundiran and Osibanjo, (2009);Iwegbue et al, (2011);Liang et al, (2014). Studies have shown that cadmium compounds in soil solution are relatively soluble, therefore, its high amount in this fraction implies a high ecological risk (Jamnika et al, 2013).…”

“…Predominance of copper in organic fraction has been reported by other researchers (Osakwe and Egharevba, 2008;Swietlik et al, 2012;Helaliet al, 2013). Devutluoglu et al, (2010) reported 30% while Liang et al, (2014) also reported 33.34% of copper contentsin this fraction. Studies have shown that substantial amount of copper in various soils is often bound to organic phase because the metal is strongly fixed by organic matter to form organic-copper compounds easily (Fagbote and Olanipekun, 2010).…”

“…Relatively low proportion of copper in these two phases has been reported (Iwegbue, 2011;Osakwe, 2012;Liang, 2014). These two phases are of special importance because metals associated with them are highly mobile and labile and are readily available for plant uptake and may eventually leach into both surface and groundwater sources thereby posing some ecological risks.…”

“…This relatively high percentage of exchangeable associated cadmium shows that cadmium in the studied soil is of anthropogenic origin and can enter food chain easily through plant uptake (Tokalioghe et al, 2003). (, Osakwe, 2010;Nogueirol andAlleoni, 2013, Kumar, 2014;Liang, 2014). Metals in these fractions are insoluble in the soil and are not available for plant uptake because they are held within the mineral matric (Chaudhary and Benerjee, 2007).…”

“…Many sequential extraction schemes have been reported in literature and studies have shown that all of them generally have some disadvantages (Davison et al, 1999, Ahmadipour, et al, 2014. However Tessier et al,(1979) procedure has been reported as the most properly researched and most widely applied (Woszczyk and Spychalsk, 2013;Liang et al,2014).…”