Application software and operating system

It was observed that the performance of the treatments varied in respect to the concentration of the heavy metal concentration of the soil samples after the bioremediation exercise. Some heavy metals such as iron, lead, cobalt, nickel and chromium were greatly reduced in all the treatment groups, while the concentration of some like manganese increased in all the treatment groups whereas the concentration of some heavy metals such as copper, zinc and cadmium varied from one treatment group to another. This is shown in Tables 4.16 and 4.17.

4.8.3.4.1 Concentration of manganese in the treated soil samples

There was an increase in the final concentration of manganese in all the treatments. In the soils treated with only bacterial inoculum, the highest concentration of manganese was observed in sample AB which had a concentration of 867.0 mg/kg while in the treatments groups treated with bacterial inoculum and gomeya, the highest concentration was observed in treatment CM with a concentration of 814.00 mg/kg compared with an initial concentration of 98.50 and 99.43 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy and dry season respectively (Table 4.1).

4.8.3.4.2 Concentration of iron in the treated soil samples

There was a decrease in the final concentration of iron in all the treatment groups for soils treated with only bacterial inoculum and those treated with both bacterial inoculum and gomeya respectively. In the soils treated with only bacterial inoculum, the lowest concentration was observed in treatment AC which had a concentration of 10.20 mg/kg (Table 4.16) while in the groups treated with bacterial inoculum and gomeya, the lowest concentration was observed in treatment ABCM with a concentration of 10.40 mg/kg (Table 4.17) compared with an initial concentration of 23.80 and 24.76 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy and dry season respectively (Table 4.1).

4.8.3.4.3 Concentration of copper in the treated soil samples

It was observed that there was an increase in the concentration of copper in soils treated with only bacterial inoculum and those treated with both bacterial inoculum

and gomeya, respectively, compared with the concentration of 1.04 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy season (Table 4.1) except in treatment group AB which had a concentration of 0.97 mg/kg.

Reduction in the concentration of copper was observed in samples B, C, BC, AC and ABC for soils treated with only bacterial inoculum with a range of 1.07-2.04 mg/kg compared with the concentration of 2.67 mg/kg observed in the contaminated soil samples used for the initial analysis during the dry season (Table 4.1).

However, an increase in the concentration of copper was observed in samples A, BM and Control with concentrations of 4.12, 5.94 and 5.84 mg/kg respectively compared with the concentration of 2.67 mg/kg observed in the contaminated soil samples used for the initial analysis during the dry season (Table 4.1).

In samples AM, CM and ABM, the concentration of copper was reduced to a range of 1.23-2.60 mg/kg compared with the concentration of 2.67 mg/kg observed in the contaminated soil samples used for the initial analysis during the dry season (Table 4.1).

4.8.3.4.4 Concentration of zinc in the bioremediated soils

Reduction was observed in the concentration of zinc in samples B, AB, AC, ABC, AM among soils treated with only bacterial inoculum and those treated with both bacterial inoculum and gomeya respectively, compared with the concentration of 1.36 and 2.55 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy and dry season respectively (Table 4.1). The highest reduction was observed in treatment AM with a concentration of 0.87 mg/kg. In treatment A and BM, the concentration of zinc was increased with values of 3.84 and 3.34 mg/kg, respectively.

4.8.3.4.5 Concentration of cadmium in the bioremediated soils

There was an increase in the concentration of cadmium in all the treatments compared with the concentration of 0.50 mg/kg observed observed in the contaminated soil samples used for the initial analysis during the rainy season (Table 4.1).

However, reduction in the concentration of cadmium was observed in samples A, B, C, AB, AC, BC, ABC, AM, ACM and BCM with a range of 1.8 to 2.9 mg/kg compared with the concentration of 2.98 observed in the contaminated soil samples

used for the initial analysis during the dry season (Table 4.1). The concentration of cadmium was increased above its concentration during the dry season in samples BM, CM, ABM, ABCM, Control and ControlM with a range of 3.1to 7.2 mg/kg.

4.8.3.4.6 Concentration of lead in the treated soil samples

Reduction was observed in the final concentration of lead in all the treatments. In the soils treated with only bacterial inoculum, the lowest concentration was observed in treatment B and BC which had a concentration of 20.8 mg/kg respectively while in the groups treated with bacterial inoculum and gomeya, the lowest concentration was observed in treatment AM with a concentration of 23.40 mg/kg compared with an initial concentration of 1505.50 and 2333.55 mg/kg observed in the contaminated soil samples during the rainy and dry season respectively (Table 4.1).

There was slight reduction in the concentration of lead in the Control group which had a final concentration of 1306.56 mg/kg compared with an initial concentration of 1505.50 and 2333.55 mg/kg observed in observed in the contaminated soil samples.

4.8.3.4.7 Concentration of cobalt in the bioremediated soil samples

There was a decrease in the final concentration of cobalt in all the treatments. In the soils treated with only bacterial inoculum, the lowest concentration was observed in treatment A and AC which had a concentration of 1.04 mg/kg respectively while in the groups treated with bacterial inoculum and gomeya, the lowest concentration was observed in treatment ABCM with a concentration of 0.92 mg/kg compared with an initial concentration of 10.50 and 13.65 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy and dry season respectively (Table 4.1).

4.8.3.4.8 Concentration of nickel in the bioremediated soil samples

There was a decrease in the final concentration of nickel in all the treatments. In the soils treated with only bacterial inoculum, the lowest concentration was observed in treatment AC which had a concentration of 0.86 mg/kg respectively while in the groups treated with bacterial inoculum and gomeya, the lowest concentration was observed in treatment ABCM with a concentration of 0.86 mg/kg compared with an

initial concentration of 31.50 and 40.56 mg/kg which was observed during the rainy and dry season respectively (Table 4.1).

4.8.3.4.9 Concentration of chromium in the bioremediated soil samples There was a decrease in the final concentration of chromium in all the treatments. In the soils treated with only bacterial inoculum, the lowest concentration was observed in treatment B which had a concentration of 1.81 mg/kg respectively while in the groups treated with bacterial inoculum and gomeya, the lowest concentration was observed in treatment BM with a concentration of 2.26 mg/kg compared with an initial concentration of 1526.00 and 1678.67 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy and dry season respectively (Table 4.1). There was slight reduction in the concentration of chromium in the Control group which had a final concentration of 1240.87 to an initial concentration of 1526.00 and 1678.67 mg/kg observed in the contaminated soil samples used for the initial analysis during the rainy and dry season respectively (Table 4.1).

CHAPTER FIVE

5.0 DISCUSSIONS