TY - JOUR
T1 - Comparative sorption of chromium species as influenced by pH, surface charge and organic matter content in contaminated soils
AU - Choppala, Girish
AU - Kunhikrishnan, Anitha
AU - Seshadri, Balaji
AU - Park, Jin Hee
AU - Bush, Richard
AU - Bolan, Nanthi
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Excessive use of chromium (Cr) in several industrial applications has a significant impact on soil biota. Chromium when present in soil and water occurs in two forms [Cr(III) and Cr(VI)] which exhibit contrasting characteristics and therefore retention of these two species is of prime importance to arrest Cr contamination in the environment. In this study, the effect of lime, elemental sulfur (to change pH), Fe(III) oxide (for surface charge) and cow manure (organic matter content) was tested on the retention capacity of Cr(III) and Cr(VI) in contaminated soils. The results showed that the addition of lime increased Cr(III) retention while elemental sulfur (So), Fe(III) oxide and cow manure increased Cr(VI) retention. The effect of So on Cr(VI) sorption is mediated through a decrease in soil pH, which facilitated an increased retention of Cr(VI) as measured by Freundlich sorption coefficient from 0.079 (in pristine soil, pH 7.15) to 21.06 L/kg (in So amended soil, pH 4.08). Also, Fe(III) oxide addition at 5% has favoured for an increase in the retention of Cr(VI) (Kf = 91.15 L/kg). Cow manure promoted Cr(VI) reduction, possibly due to the presence of functional groups that are present along with dissolved organic carbon and also by increased microbial activity. It is concluded that the mitigation of Cr toxicity is brought about by the addition of amendments which manipulate the properties of soil to increase retention of Cr(III) and Cr(VI).
AB - Excessive use of chromium (Cr) in several industrial applications has a significant impact on soil biota. Chromium when present in soil and water occurs in two forms [Cr(III) and Cr(VI)] which exhibit contrasting characteristics and therefore retention of these two species is of prime importance to arrest Cr contamination in the environment. In this study, the effect of lime, elemental sulfur (to change pH), Fe(III) oxide (for surface charge) and cow manure (organic matter content) was tested on the retention capacity of Cr(III) and Cr(VI) in contaminated soils. The results showed that the addition of lime increased Cr(III) retention while elemental sulfur (So), Fe(III) oxide and cow manure increased Cr(VI) retention. The effect of So on Cr(VI) sorption is mediated through a decrease in soil pH, which facilitated an increased retention of Cr(VI) as measured by Freundlich sorption coefficient from 0.079 (in pristine soil, pH 7.15) to 21.06 L/kg (in So amended soil, pH 4.08). Also, Fe(III) oxide addition at 5% has favoured for an increase in the retention of Cr(VI) (Kf = 91.15 L/kg). Cow manure promoted Cr(VI) reduction, possibly due to the presence of functional groups that are present along with dissolved organic carbon and also by increased microbial activity. It is concluded that the mitigation of Cr toxicity is brought about by the addition of amendments which manipulate the properties of soil to increase retention of Cr(III) and Cr(VI).
KW - Chromium
KW - Elemental sulfur
KW - Retention
KW - Surface charge
UR - http://www.scopus.com/inward/record.url?scp=84992342813&partnerID=8YFLogxK
U2 - 10.1016/j.gexplo.2016.07.012
DO - 10.1016/j.gexplo.2016.07.012
M3 - Article
AN - SCOPUS:84992342813
SN - 0375-6742
VL - 184
SP - 255
EP - 260
JO - Journal of Geochemical Exploration
JF - Journal of Geochemical Exploration
ER -