Environmental Engineering Reference
In-Depth Information
Table 1
(continued)
pH
TH (mg/l)
Cl
−
(mg/l)
F
−
(mg/l)
NO
3
−
(mg/l)
Sept.
09
April
10
Sept.
09
April
10
Sept.
09
April
10
Sept.
09
April
10
Sept.
09
April
10
S. No
W
42
7.6
8.0
910
1,000
280
270
3.8
3.8
63
60
W
43
7.8
7.6
926
1,017
210
200
3.7
3.5
33
30
W
44
7.6
7.8
969
964
220
200
4.5
4.4
35
35
W
45
8.0
7.6
1,067
1,133
320
300
3.7
3.7
32
30
W
46
8.2
8.0
1,124
1,219
410
400
3.8
3.8
90
85
W
47
8.3
8.2
1,240
1,306
378
370
4.0
3.8
100
90
W
48
8.5
8.3
1,322
1,413
480
460
4.2
4.0
110
95
W
49
8.0
8.0
1,333
1,898
450
290
4.5
4.2
90
100
W
50
8.2
7.8
1,474
1,479
380
300
4.0
4.5
78
90
Min
7.0
7.0
246
413
72
70
1.1
1
20
20
Max
8.6
8.6
1,474
1,898
480
460
7.1
7.0
110
100
Mean
8.0
7.86
676.4
744.7
211.9
195.3
3.53
3.4
65.94
64.14
S.D
0.40
0.44
256.8
295.6
102.8
94.8
1.12
1.12
21.02
19.75
fluoride dissolution activity (Saxena and Ahmed
2001
). However, during April 2010 it
ranges from 7 to 8.6 with an average value of 7.84. This shows that the ground water
of the study area is mainly alkaline in nature. The total hardness values range from 246
to 1,474 mg/l during September 2009 and 413 to 1,898 mg/l during April 2010; around
80 % of the samples were found to be very hard in nature. The high value of total hard-
ness in supply water may cause corrosion of pipes, resulting in the pressure of certain
heavy metals such as cadmium, copper, lead and zinc in drinking water. Chlorides
ranged between 72 and 480 mg/l for September 2009 and 70-460 mg/l during April
2010, respectively. The fluoride values range from 1.1 to 7.1 mg/l during September
2009 and 1 to 7.0 mg/l during April 2010. Nitrate (NO
3
−
) in the ground water varies
from 20 to 110 mg/l during September 2009 and 20 to 100 mg/l during April 2010.
The analytical results of physical and chemical parameters of ground water were
compared with the standard guideline values as prescribed by the World Health
Organization (WHO
1983
) and Indian Standards Institute (ISI
1983
) for drinking
and public health purposes (Table
2
). The table shows the most desirable limits of
various parameters and found that all the parameters analyzed were above the desir-
able limits of both the standards.
Impact of Fluoride on Human Health
Dental Fluorosis
Generally, present ingestion of ground water having a fluoride concentration above
1.5-2.0 mg/l may lead to dental mottling, an early sign of dental fluorosis which is
characterized by opaque white patches on teeth. In advanced stages of dental
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