In a municipal solid waste (MSW) compost
field,
Kochia scoparia
, an easy-to-grow weed plant, gradually
invaded the experiment site and became the dominant
species after 4 years’ succession. Ethylenediaminetetraacetic
acid (EDTA) solution at five rates 0, 25,
50 mmol L
-1, 25 mmol L
-1 + 1 g L
-1 ammonium sulfate
(NH
4)
2SO
4, and 50 mmol L
-1 + 1 g L
-1 (NH
4)
2SO
4
was added to the tested plant root medium. The effects of
EDTA and (NH
4)
2SO
4 on Pb and Cr distribution in
K. scoparia were investigated. Results suggested that plant
biomass increased greatly with height, showing an
‘inversion pyramid’ pattern in spatial structure. At the
level of 50 mmol L
-1 EDTA, single additions and combined
additions with (NH
4)
2SO
4 increased Pb and Cr
concentrations in plant shoots at different heights. Lead and
Cr uptakes increased toward the top of the shoot. Combined
application of 50 mmol L
-1 EDTA and (NH
4)
2SO
4
increased Pb uptakes by 21.6, 19.2, 111.3, 124.3, and
154.0 % in 0–30, 30–60, 60–90, 90–120, and over 120 cm
spatial shoots, respectively, as compared to those of controls.
The increment for Cr uptake was 244.5, 281.7, 100.0,
77.2, and 187.4 %. The relationship between Pb and Cr
concentrations in plant shoots and spatial height was found
to be positively linear and statistically significant at 1 %
level at 50 mmol L
-1 EDTA alone and 25 mmol L
-1
EDTA together with (NH
4)
2SO
4. Results presented here
indicated that
K. scoparia had potential in removal of Pb
and Cr from MSW compost with the combined application
of EDTA and (NH
4)
2SO
4.