ASSESSMENT OF HEAVY METALS CONTAMINATION IN SEDIMENT OF OBII STREAM, UFUMA, ANAMBRA STATE, NIGERIA

Abstract

This research work was conducted to assess the levels of heavy metal (Cd, Pb, Ni, Cu, Zn, and Fe) concentrations in sediment of Obii stream, Enugwu-Abo Ufuma in Orumba North; Anambra State. Sediment pollution assessment was undertaken using geoaccumulation index (Igeo), pollution Load Index (PLI), contamination factor (Cf) and ecological factor (Er). The contamination factor (mg/kg) in dry and rainy season respectively showed Cd: (0.520, 0.207); Pb: (0.026, 0.000); Ni: (0.009, 0.002); Cu: (0.004, 0.000); Zn: (0.126, 0.020); and Fe: (0.001, 0.000) while the ecological factor (mg/kg) in dry season and rainy season respectively showed Cd:(1.040, 0.415); Pb: (0.132, 0.001); Ni: (0.046, 0.010); Cu: (0.023, 0.004) and Zn: (0.126, 0.020).The mean geoaccumulation indices (Igeo) suggested that the magnitude of heavy metals pollution of the sediment followed the order Cd > Zn >Pb > Ni > Cu > Fe in dry season and Cd > Zn >Ni >Cu > Fe > Pb during the rainy season. The pollution load index (PLI) calculated for all the heavy metals during the dry and rainy seasons were 0.00006 mg/kg and 0.00545 mg/kg respectively.Igeo for the analyzed metals suggested that sediment from this stream ranged from unpolluted to moderately polluted degree of pollution.