Environmental Engineering Reference
In-Depth Information
R
ESULTS
Heavy Metal Pollution of Water Bodies in Whole Nation
The result of potential ecological risk of heavy metal pollution in water ecosystems of
China is shown in Table 1 and Table 2. Based on the published data in literatures we
collected, grade of the integrated potential ecological risk index
RI
was ―Stronger‖ (
RI
=1550)
for whole nation. Furthermore, the sequence of individual heavy metal potential risk index
E
i
f
was Cd>Hg>As> Cu>Pb>Cr>Zn for whole China, but except Cd, Hg and As, the
E
i
f
grade of
Cu, Pb, Cr and Zn was ―Slight‖.
Heavy Metal Pollution of Water Bodies in Different Industrial Districts
The results also show that grades of integrated potential ecological risk index
RI
of
industrial districts Dongbei, Huabei, Huanan, Huaxi and Huazhong were ―stronger‖, and
RI
grades of Huangdong and Xibei were ―strong‖. Nevertheless, the order of
RI
of industrial
districts was Dongbei>Huabei> Huazhong>Huanan>Huaxi>Xibei>Huadong. For 7 industrial
districts, the tendency of
E
i
f
was the same as that of the whole nation, and Cd, Hg and As
were the most serious polluted heavy metals in the water bodies (also see in Appendices
Table S5). Specifically, for Cd, except
E
i
f
grade of Xibei was ―Strong‖,
E
i
f
grade of the left
industrial districts were ―Very strong‖, especially the
E
i
f
grade of Dongbei was the highest
(
E
i
f
=8882). For Hg,
E
i
f
grades of Huabei, Xibei and Huazhong were ―Very strong‖,
E
i
f
grade
of Dongbei was ―Stronger‖,
E
i
f
grades of Huadong and Huaxi were ―Strong‖, but
E
i
f
grade of
Huanan was ―Medium‖. For As, except
E
i
f
grade of Dongbei,
E
i
f
grades of Huaxi and
Huazhong were ―Medium‖,
E
i
f
grades of other industrial districts were ―Slight‖. Thus, the
pollution of Cd was most severe, and the pollution of Hg and As was less severe than Cd in
water bodies across the industrial districts.
Heavy Metal Pollution in Different Water Ecosystems
Results in Table 2 exhibit that grades of integrated potential ecological index
RI
of 4
types water ecosystems were ―Stronger‖, and the sequence was River>Sea>Lake>Wetland.
Among 4 types of water bodies, grades of potential ecological risk index
E
i
f
of Cr, Cu, Pb and
Zn were ―Slight‖. However, for As,
E
i
f
grade of River was ―Medium‖; but
E
i
f
grade of Lake,
Sea and Wetland were ―Slight‖; for Cd,
E
i
f
grade of 4 types of water bodies were ―Very
strong‖, and the sequence was: Sea>River>Lake>Wetland; for Hg,
E
i
f
grade of Lake and
River were ―Very strong‖, while
E
i
f
grade of
Wetland was ―Strong‖, but
E
i
f
grade of Sea was
―Medium‖.
Comparisons of potential ecological risk factors among 4 types of water ecosystems in 7
industrial districts are exhibited in Figure 1. For Dongbei, Huabei, Huadong, Huanan, Huaxi,
Huazhong and Xibei, Sea, River, Lake, River, Lake, River was most seriously polluted
respectively.
