Bioscience Methods 2017, Vol.8, No.1, 1-18
12
both seasons (Figure 3). This is an indication of low level of pollution in soil associated with the discharge of
cassava mill effluent into the soil.
Figure 3 Average Pollution index using median mean of heavy metals concentration in cassava mill effluent contaminated soil
Note: API > 1.0 is an indication of low contamination level of the soil
Figure 4 presents metal pollution index of heavy metals concentration in cassava mill effluents contaminated soil
in a rural community in the Niger Delta region of Nigeria. The MPI was apparently higher in the dry season
compared to the wet season, with the values ranging from 4.01 – 11.05. This could be due to dilution effects. The
MPI was higher than 1 in all the locations. This is an indication of deterioration in the environment with regard to
heavy metals concentration (El-Said and Youssef, 2013; El-Metwally et al., 2017). The values reported in this
study had some similarity with the work of Sarala and Sabitha (2012) that reported MPI in the range of 5.63 –
7.98 in based on heavy metals in soil near sugar mill at varying depth of 0, 5 and 10cm. But higher than the value
of 1.08 – 1.50 in sediment of red sea ports of Egypt reported by El-Metwally et al. (2017).
Figure 4 Metal Pollution index of heavy metal concentration in cassava mill effluent contaminated soil
Figure 5 present the sum of pollution index of heavy metals concentration in cassava mill effluent contaminated
soil in a rural community in the Niger Delta region of Nigeria. The sum of pollution index ranged from 1461.35 –
5805.36 and 2757.03 – 4251.09 in dry and wet season respectively. Apart from location LE in both season, the
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet
LA LB LC LD LE
Average pollution index using median mean
Locations
0
2
4
6
8
10
12
Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet
LA
LB
LC
LD
LE
