Environmental Engineering Reference
In-Depth Information
and K
+
). However, the pH values of the irrigated sites were about 1.0 unit higher than that
of the control.
As supported by Nyamangara & Mzezewa (1999), the higher soil pH at the irrigated
sites is due to the “alkalinizing” effect of effluent used for irrigation. Thus the pH values
of the irrigated sites were significantly higher than that of the control. In all the sites,
there were no marked pH variations along the soil profile.
Table 10.5. Ponds effluent characteristics during the
study period.
Parameter
Units
07/03/01
03/04/01
10/04/01
Mean
Standard deviation
TKN
mg/l
35.60
34.80
35.00
35.10
0.42
NH
4
mg/l
13.20
12.80
15.20
13.70
1.29
NO
3
mg/l
0.90
1.20
1.00
1.03
0.15
P
mg/l
3.02
3.00
2.80
2.94
0.12
K
mg/l
29.70
30.40
29.90
30.00
0.36
Na
mg/l
46.00
46.60
47.70
46.00
0.86
Mg
mg/l
8.90
9.70
11.50
10.00
0.45
Ca
mg/l
22.20
26.60
23.10
24.00
2.32
pH
[-]
7.23
7.18
7.10
7.17
0.07
EC
µS/cm
950
1021
978
983
35
Zn
mg/l
0.06
0.05
0.06
0.06
0.01
Cu
mg/l
0.00
0.01
0.01
0.01
0.01
Cd
mg/l
0.00
0.05
0.02
0.02
0.03
Cr
mg/l
0.02
2.18
2.01
1.40
1.20
Table 10.6. Soil characteristics - general
parameters and nutrients.
Depth
[cm]
Site
pH [-
]
EC
[µS/cm]
Ortho-P
[mg/l]
Ammonia
[mg/l]
Nitrate
[mg/l]
0-30
C1
4.2
27
21
3.8
1
0-30
C2
4
22
77
3.06
0
0-30
C3
3.5
588
15
2.5
0
0-30
C4
3.8
26
104
2.8
1
Average 3.88
165.75
54.25
2.31
0.50
0-30
F1
5.5
223
172
3
15
