Speciation of Lead, Cadmium and Nickel in Soils Around an Effluent Discharge From an Oil Processing Factory in Port-Harcourt South-South Nigeria

Abstract

Speciation study to investigate the concentration of Pb, Cd and Ni in various fractions of soils around an 
effluent discharge from an oil processing factory in Port-Harcourt using sequential extraction procedure 
and Atomic Absorption Spectrometry (AAS) respectively was carried out. Results obtained indicated a 
mean concentration of these metals in the order of Ni > Pb > Cd. The total observed concentration with 
reference to the distance ranged from 0.80 -1.90 µg/g for Pb; 0.16 - 0.29 µg/g for Cd and 2.53 – 7.20 µg/g 
for Ni. The Igeo values of ≤ 0 which showed that these two metals were below the world surface average. 
Consequently, a negative Igeo was observed for Pb except for few chemical specie with Igeo values below 1, 
which was an indication that the soil quality was unpolluted to moderately polluted. The exchangeable 
cation fractions were all below the lowest effect level and are therefore not detrimental to human health.