Fractionation of Cd, Cr, Pb and Ni in roadside soils of Uyo, Niger Delta Region: Nigeria using the optimized BCR sequential extraction technique

Abstract

The optimized BCR sequential extraction procedure was applied to nine roadside soil samples for the determination of Cd, Cr, Pb and Ni. The extractable metals were isolated into three operationally defined fractions viz: acid extractable, reducible and oxidizable. The residue was treated with aqua regia solution. Metal analysis was done using flame atomic absorption spectrophotometry with airacetylene flame. Results obtained showed the concentrations of the metals as relative abundance in the mobile phases of the samples (based on the sum of the first three fractions) are in the following order: Cd(91.9) [ Pb(82.8) [ Ni(49.5) [ Cr(39.0). The most non-mobilizable metals were Cr and Ni which are generally lithogenic, associated with the silicate matrix, and the order is as follows: Cr(61.0) [ Ni(50.5) [ Pb(17.2) [ Cd(8.1). The recovery of all the metals expressed as the ratio of total metal concentration to fractional sum of the optimized BCR sequential extraction procedure was of the order: Cr(95.6) [ Pb(95.0) [ Ni(94.8) [ Cd(92.4).

Remediation of deltamethrin contaminated cotton fields: residual and adsorption assessment

“…Significant positive and negative correlation is exhibited by Cd -Cr and Zn-Cd, Zn-Cr, which has also been reported previously [14]. In addition, the positive correlation between Zn-Pb, Cu-Pb, Ni-Cu, Ni-Cd, Ni-Cr and Ni-Pb, matches a previous study [15].…”

Fractionation, Mobility, and Sources of Selected Heavy Metals in Topsoils from the Middle Black Sea Region of Turkey

“…Although, metals associated with the organic fraction are relatively stable and remain for longer periods, they can be mobilized under strong oxidizing conditions by decomposition processes . Metals found in the RES fraction are generally accepted as non‐mobile, since they are entrapped within the crystal structure of the minerals . The mobility of metals has been assessed via the mobility factor (MF) : where F EXC , F CAR , and F FeMnOx denote the easily exchangeable, acid‐soluble and reducible fractions, respectively and ∑ F represents the sum of all fractions.…”

“…Although, metals associated with the organic fraction are relatively stable and remain for longer periods, they can be mobilized under strong oxidizing conditions [28] by decomposition processes [10]. Metals found in the RES fraction are generally accepted as non-mobile, since they are entrapped within the crystal structure of the minerals [8,9,28]. The mobility of metals has been assessed via the mobility factor (MF) [8,[29][30][31]:…”

Fractionation and mobility of cadmium and lead in soils of Amol area in Iran, using the modified BCR sequential extraction method

“…Mobility and bioavailability of heavy metals in soil is determined by their chemical forms (Jaradat et al, 2006;Umoren and Udousoro, 2009). Sequential extractions, such as the Tessier procedure (Tessier et al, 1979), have been applied to soils contaminated by various sources.…”

“…Exchangeable and bound to carbonates are considered to be bioavailable; reducible and oxidisable fractions may be potentially bioavailable, while the residual fraction is mainly not available to either plants or micro organisms (Alvarez et al, 2006;Obrador et al, 2007). Soil properties such as pH, texture and organic matter are responsible for the chemical forms and bioavailability of heavy metals in soils (Umoren and Udousoro, 2009). Numerous studies have investigated heavy metal concentrations in soils all around the world (Kabata-Pendias, 1993).…”