Phytoremediation Of Some Heavy Metals On Oil Contaminated Soil Using Little Iron Weed Augmented With Pig Dung:- Orji Chukwuma C

ABSTRACT The aim ofthis study is to evaluate the phytoremediation of selected heavy metals (Co, As and Fe) in a spent oil contaminated soil using Cyanthillium cinereum augmented with pig dung. The sample (pig dung) was collected from a ranch while the soil samples were obtained from the top soil (0—15 cm), collected from noncontaminated area. These locations are within the campus of Michael Okpara University of Agriculture, Umudike. These samples were grouped into five (5) different groups viz: group 1 served as control while group two was Soil + spent oil and, group 3 was Soil + spent oil + pig dung. Groups 4 and 5 were Soil + spent oil + iron weed and Soil + spent oil + pig dung + iron weed, respectively. These groupings were made for both uncontaminated and contaminated soil, each. From the results, it was observed that cobalt concentration in uncontaminated soil sample (control) (2.29 ± 0.02) was significantly (p<0.05) higher than that of groups 4 (1.38 ±0.01) and 5 (0.00 ± 0.00) while the contaminated sample of group 1 (0.56 ± 0.01) has a significant (p<0.05) and non-significant (p>0.05) decrease when compared with groups 4 (1.91 ± 0.01) and 5 (0.57 ± 0.01), respectively. The results of arsenic showed absence of the metal in all samples of both contaminated and uncontaminated samples. Also, the results of iron indicated that the control ofthe uncontaminated (611.09 ± 0.58) and contaminated (594.85 ± 0.83) showed significant (p<0.05) increase when compared with groups 5 (584.41 ± 0.59) and a non-significant (p>0.05) decrease when compared with group 4 (613.92 ± 1.09). With respect to physico-chemical parameters analysed, total organic matter showed that control of the uncontaminated (1.75 ± 0.00) and contaminated soils (5.13 ± 0.00) were significantly (p<0.05) lower when compared with group 5 (6.29 ± 0.01), for uncontaminated and (6.72 ± 0.02), for contaminated samples, respectively, while result of cation exchange capacity showed that control had a significant (p<0.05) decrease when compared with group 5 (7.15 ± 0.01) and a non-significant difference when compared with group 4 (1.74 ± 0.01). from these results, it was observed that the plant - little iron weed had a positive effect on polluted soil samples and therefore, recommended for use in phytoremediation.