TY - JOUR
T1 - Attenuation of Metal Bioavailability in Acidic Multi-Metal Contaminated Soil Treated with Fly Ash and Steel Slag
AU - Qiu, Hao
AU - Gu, Hai Hong
AU - He, Er Kai
AU - Wang, Shi Zhong
AU - Qiu, Rong Liang
PY - 2012/8
Y1 - 2012/8
N2 - A pot experiment was conducted with multi-metal (Pb, Cd, Cu, and Zn) contaminated acidic soil to investigate changes in available metal burden resulting from the application of industrial wastes (fly ash and steel slag). The efficiency of amendments-induced metal stabilization was evaluated by diffusive gradients in thin films (DGT), sequential extraction, and plant uptake. The stability of remediation was assessed by an acidification test and by chemical equilibrium modeling. Addition of fly ash (20 g kg-1) and steel slag (3 g kg-1) resulted in similar increase in soil pH. Both amendments significantly decreased the concentrations of metals measured with DGT (CDGT) and the metal uptake by Oryza sativa L. Significant correlations were found between CDGT and the concentration of a combination of metal fractions (exchangeable, bound to carbonates, and bound to Fe/Mn oxides), unraveling the labile species that participate in the flux of metal resupply. The capability of metal resupply, as reflected by the R (ratio of CDGT to pore water metal concentration) values, significantly decreased in the amended soils. The CDGT correlated well with the plant uptake, suggesting that DGT is a good indicator for bioavailability. Acidification raised the extractable metal concentration in amended soil but the concentration did not return to the pre-amendment level. Equilibrium modeling indicated that the soil amendments induced the precipitation of several Fe, Al and Ca minerals, which may play a positive role in metal stabilization. Chemical stabilization with alkaline amendments could be an effective and stable soil remediation strategy for attenuating metal bioavailability and reducing plant metal uptake.
AB - A pot experiment was conducted with multi-metal (Pb, Cd, Cu, and Zn) contaminated acidic soil to investigate changes in available metal burden resulting from the application of industrial wastes (fly ash and steel slag). The efficiency of amendments-induced metal stabilization was evaluated by diffusive gradients in thin films (DGT), sequential extraction, and plant uptake. The stability of remediation was assessed by an acidification test and by chemical equilibrium modeling. Addition of fly ash (20 g kg-1) and steel slag (3 g kg-1) resulted in similar increase in soil pH. Both amendments significantly decreased the concentrations of metals measured with DGT (CDGT) and the metal uptake by Oryza sativa L. Significant correlations were found between CDGT and the concentration of a combination of metal fractions (exchangeable, bound to carbonates, and bound to Fe/Mn oxides), unraveling the labile species that participate in the flux of metal resupply. The capability of metal resupply, as reflected by the R (ratio of CDGT to pore water metal concentration) values, significantly decreased in the amended soils. The CDGT correlated well with the plant uptake, suggesting that DGT is a good indicator for bioavailability. Acidification raised the extractable metal concentration in amended soil but the concentration did not return to the pre-amendment level. Equilibrium modeling indicated that the soil amendments induced the precipitation of several Fe, Al and Ca minerals, which may play a positive role in metal stabilization. Chemical stabilization with alkaline amendments could be an effective and stable soil remediation strategy for attenuating metal bioavailability and reducing plant metal uptake.
KW - Acidification
KW - Chemical stabilization
KW - Diffusive gradients in thin films (DGT)
KW - Heavy metal
KW - Remediation
UR - https://www.scopus.com/pages/publications/84862743704
U2 - 10.1016/S1002-0160(12)60039-3
DO - 10.1016/S1002-0160(12)60039-3
M3 - 文章
AN - SCOPUS:84862743704
SN - 1002-0160
VL - 22
SP - 544
EP - 553
JO - Pedosphere
JF - Pedosphere
IS - 4
ER -