Jul. 2010- Center of Popularization and Development for Water Resources Sci-Tech, Zhejiang Province Sep. 2007-Jun. 2010 Research Center of Eco-Environmental Sciences, Chinese Academy of Sciences Sep. 2003-Jul. 2007 Northwest A & F University
Abstract: Using soil incubation experiments, the effect of red mud addition on the fractionation and bioaccessibility
of Pb, Zn and As in combined contaminated soil was studied. The results showed that red mud addition
could significantly decrease the concentration of HOAc-extractable Pb and Zn in soil. Compared with
the control, 5% red mud addition could significantly reduce the concentrations of HOAc-extractable Pb
and Zn in soil after 1, 2 and 3 months of incubation [62.5, 65.3 and 73.5% decrease (Pb), 56.7, 65.8 and
67.4% decrease (Zn)]. Whereas adding red mud could remarkably increase the concentrations of specific
absorbed As and residual As in soil. The result of a simple bioavailability extraction test (SBET) indicated
that all treatments with red mud addition markedly reduced the concentration of bioaccessible Zn but
increased the concentration of bioaccessible As in soil, while having little effect on the concentration of
bioaccessible Pb in soil. After 3 months incubation, all treatments including 1, 2 and 5% red mud addition
reduced the concentration of bioaccessible Zn by 53.1–56.7% compared with the control, but increased the
concentration of bioaccessibleAs by 1.81–6.25 times. The results suggested that red mud is an additive with
potential for the remediation soil contaminated soil by combinations of heavy metals, although it should
be added based on the different heavy metals in the soil. Combined use of red mud and hyperaccumulators
to remediate heavy metal contaminated soil needs further study.
Abstract: Effect of bone char addition on the fractionation and bio-accessibility of lead (Pb) and Zinc (Zn) in combined
contaminated soil was studied by batch soil column incubation experiment. Four treatments were
designed: control (without bone char), 1%, 2% and 5% bone char addition (by weight). The results showed
that all treatments with bone char addition could significantly decrease the concentration of HOAc
extractable Pb (P < 0.05). Compared with the control the concentration of HOAc extractable Pb was
decreased by 66.85%, 83.69% and 97.40%, respectively, in 1%, 2% and 5% bone char amended soils after
3 months incubation. The treatment with 5% bone char addition significantly decreased (P < 0.05) the
concentration of HOAc extractable Zn by 47.80%, 43.63% and 41.35%, respectively, after 1, 2 and 3 months
incubation. All treatments, including 1%, 2% and 5% bone char addition, significantly decreased (P < 0.05)
the concentration of bio-accessible Pb after 3 months incubation, however, only the treatment with 5%
bone char addition significantly decreased (P < 0.05) the concentration of bio-accessible Zn after
3 months incubation. The results highlighted the potential of bone char amendments to reduce the bioavailability
of Pb and Zn in contaminated soil.
