Concentration of Mercury and Other Heavy Metals in Central India
493
labile (the inorganic), non-labile (the organic) and total (the inorganic plus the
organic) mercury in the surface water of 30 reservoirs are given in Table 2. The
concentration of total mercury in 20 ponds and 10 river basins was found to be in
the range of 2.0-17.1 and 1.4-13.6 ppb, respectively. The pH of water affects the
Hg level and a very high Hg concentration was seen in the surface water, whose
pH was >6.9. The stagnant surface water of ponds contained a very high Hg
concentration «17.1 ppb), which may be due to contamination with greenish
algal bloom or iron compounds at a high level. However, the Hg concentration
was also very high in mobile (river) water of the iron belt area, possibly due to
contamination with iron compounds at a high level (Table 2). The concentration
of organic as well as total Hg was higher in the stagnant than in the mobile water
and the ratio of organic to inorganic Hg was in the range of 9.0-24.5, and 1.9-3.6
in 20 ponds and 10 river basins, respectively (Table 3). The dispersion of
mercury in the groundwater was examined in water near the sampling sites. The
groundwater samples were collected using water-sampler equipment (Pandey
et al. 1979). Hg-contamination of the groundwater was determined and found in
the range of 0.4-3.5 ppb. The effect of the depth profile of the groundwater
aquifers on the Hg level was seen to be significant in the dolomite rock-bearing
areas i.e. Raipur and Bhilai (Table 4). The highest level of mercury pollution in
the water of the iron mineral belt was 17.1 ppb, mostly due to natural phenomena,
i.e. weathering of iron ore, soil erosion or atmospheric deposition (Kamavisdar
and Patel 1997; Patel and Tripathi 1997).
5.2
Mercury in Sediments
Sediment samples of ponds and rivers from differently located geographical
environments of central India, the industrial towns (Raipur, Bhilai, Bilaspur),
thermal power plant (Korba), coal mine area (Katghora), and remote iron
mineral areas (Kanker, Jagadalpur, Sukuma, Antagargh, Dantewada) were
Table 3. Speciation of Hg in surface water
Location
Site
Speciation of Hg in surface water (ppb)
Ratio
Non-Iabile:labile
Labile
Non-labile
Total
Raipur
Urla pond-III
0.9
10.2
11.3
11.3
Kharun river
0.8
1.5
2.3
1.9
Bilaspur
Pond
0.3
2.9
3.2
9.6
Arpa river
0.6
1.9
2.5
3.2
Korba
Pond-I
0.2
4.9
5.1
24.5
Antagarh
Pond
0.7
9.3
10.0
13.3
River
2.0
7.3
9.3
3.6
Kanker
Pond
0.7
6.3
7.0
9.0
River
1.6
4.2
5.8
2.6
493
labile (the inorganic), non-labile (the organic) and total (the inorganic plus the
organic) mercury in the surface water of 30 reservoirs are given in Table 2. The
concentration of total mercury in 20 ponds and 10 river basins was found to be in
the range of 2.0-17.1 and 1.4-13.6 ppb, respectively. The pH of water affects the
Hg level and a very high Hg concentration was seen in the surface water, whose
pH was >6.9. The stagnant surface water of ponds contained a very high Hg
concentration «17.1 ppb), which may be due to contamination with greenish
algal bloom or iron compounds at a high level. However, the Hg concentration
was also very high in mobile (river) water of the iron belt area, possibly due to
contamination with iron compounds at a high level (Table 2). The concentration
of organic as well as total Hg was higher in the stagnant than in the mobile water
and the ratio of organic to inorganic Hg was in the range of 9.0-24.5, and 1.9-3.6
in 20 ponds and 10 river basins, respectively (Table 3). The dispersion of
mercury in the groundwater was examined in water near the sampling sites. The
groundwater samples were collected using water-sampler equipment (Pandey
et al. 1979). Hg-contamination of the groundwater was determined and found in
the range of 0.4-3.5 ppb. The effect of the depth profile of the groundwater
aquifers on the Hg level was seen to be significant in the dolomite rock-bearing
areas i.e. Raipur and Bhilai (Table 4). The highest level of mercury pollution in
the water of the iron mineral belt was 17.1 ppb, mostly due to natural phenomena,
i.e. weathering of iron ore, soil erosion or atmospheric deposition (Kamavisdar
and Patel 1997; Patel and Tripathi 1997).
5.2
Mercury in Sediments
Sediment samples of ponds and rivers from differently located geographical
environments of central India, the industrial towns (Raipur, Bhilai, Bilaspur),
thermal power plant (Korba), coal mine area (Katghora), and remote iron
mineral areas (Kanker, Jagadalpur, Sukuma, Antagargh, Dantewada) were
Table 3. Speciation of Hg in surface water
Location
Site
Speciation of Hg in surface water (ppb)
Ratio
Non-Iabile:labile
Labile
Non-labile
Total
Raipur
Urla pond-III
0.9
10.2
11.3
11.3
Kharun river
0.8
1.5
2.3
1.9
Bilaspur
Pond
0.3
2.9
3.2
9.6
Arpa river
0.6
1.9
2.5
3.2
Korba
Pond-I
0.2
4.9
5.1
24.5
Antagarh
Pond
0.7
9.3
10.0
13.3
River
2.0
7.3
9.3
3.6
Kanker
Pond
0.7
6.3
7.0
9.0
River
1.6
4.2
5.8
2.6