Assessment of metal contamination in sediment from Woji Creek, Niger Delta Region of Nigeria

Abstract

ABSTRACT The level of metallic (Cd, Ni, Fe, Pb, Cu) contamination in the sampled sediments of five stations (S1, S2, S3, S4 and S5) from Woji creek bed between August and October 2019 was appraised using pollution load index (PLI), contamination factor (CF) and geoaccumulation index (I geo). Results from the sediment analysis showed that Cd was not detected in stations 1, 3 and 5 in September, however, there was a high concentration of Cd in station 3 in October (43.590 ± 2.013 mg/kg). The concentration of Ni was highest in station 4 in August (247.682 ± 6.026 mg/kg). The mean spatial concentration of Pb ranged from 57.774 ± 75.647 mg/kg in October to 344.153 ± 112.184 mg/kg in August. Spatially, the highest concentration of Fe was measured in August (23.945 ± 17.828 mg/kg). Station 2 had the lowest concentration of Fe in the sediment temporally (5.667 ± 6.381 mg/kg) while station 3 had the highest concentration (19.496 ± 24.090 mg/kg); 37.188 ± 27.821 mg/kg (station 3) was the highest mean temporal concentration Cu, while station 2 had the lowest mean concentration of Cu (0.471 ± 0.358 mg/kg).The PLI values were in the trend: S3 (2.58 x 1015) >S4 (5.29 x 1014) > S1 (3.52 x 1014) > S5 (3.71 x 1013) > S2 (4.64 x 1012).These results indicated that the highest concentration of studied metals was found in S3 (except for Ni in S4), which emphasised the possible input of metallic matter into the sediment from the various operations along the creek connected with the disposal of metallic particulate wastes. All the metals present in the sampled sediments (except for Cu in S2) had concentrations between threshold effect level (TEL) and probable effect levels (PEL), which suggests the influence of unfavourable biological processes taking place from time to time.