Hydrocarbon wastes generated from remediation activities contain Total Petroleum Hydrocarbon (TPH), Polyaromatic Hydrocarbon (PAH) and Heavy Metals whose respective concentrations are yet to be determined. There is li...Hydrocarbon wastes generated from remediation activities contain Total Petroleum Hydrocarbon (TPH), Polyaromatic Hydrocarbon (PAH) and Heavy Metals whose respective concentrations are yet to be determined. There is limited available literature particularly in Nigeria, on whether the concentration of these wastes after treatment exceeds permissible limits. The present work aims to determine the concentration of petroleum hydrocarbon in the residual ash from the treated (incinerated) oily wastes from the Bodo-Ogoni remediation activities. Oily wastes residual ash samples were collected from six treatment sites, each divided into four replicates in a Completely Randomized Design. A total of twenty-four residual ash samples were collected and taken to National Oil Spill Detection and Response Agency (NOSDRA) Reference Laboratory, Port Harcourt for extraction. The concentration of TPH, PAH and heavy metals in untreated hydrocarbon wastes were also determined and used for the control experiment. The extracts were analyzed using AGILENT 7890A-GC and Atomic Absorption Spectrophotometer (AAS) modelled 240FS, manufactured in USA. The results show six residual pollutants;Cadmium, Lead, Zinc, Manganese, TPH and PAH below the Nigeria Department of Petroleum Resources (DPR) Intervention Level but exceeded the DPR Target Level for TPH and PAH. The descending order of concentration of PAH obtained from the treatment sites gwere;1.24 + 2.4 mg/kg (Paschal), 4.76 + 7.48 mg/kg (ITS), 10.46 + 14.68 mg/kg (TMCH) and 16.14 + 6.36 mg/kg (Mosab). Similarly, the concentration of TPH was 320.18 + 355.13 mg/kg (TMCH), 463.25 + 205.29 mg/kg (ICREN) and 501.11 + 300.79 mg/kg (Networld) against TPH 12,000 mg/kg, PAH 23 mg/kg, Cadmium 0.15 mg/kg, Lead 0.59 mg/kg, Zinc 3.45 mg/kg and Manganese 2.8 mg/kg (untreated wastes). Two treatment sites only recorded concentration of heavy metals, while four reformed inefficiently and couldn’t detect the concentration of some residual pollutants in the ash samples and consequently, recorded below detectable level (BDL). Statistical analysis showed a significant difference (P 0.05) between heavy metal content across sites and their target values. The results showed that the remediation activities had a strong impact on the concentration of TPH and PAH, and a weak impact on the concentration of heavy metals in the treated oily wastes. The implications of the results are discussed.展开更多
文摘Hydrocarbon wastes generated from remediation activities contain Total Petroleum Hydrocarbon (TPH), Polyaromatic Hydrocarbon (PAH) and Heavy Metals whose respective concentrations are yet to be determined. There is limited available literature particularly in Nigeria, on whether the concentration of these wastes after treatment exceeds permissible limits. The present work aims to determine the concentration of petroleum hydrocarbon in the residual ash from the treated (incinerated) oily wastes from the Bodo-Ogoni remediation activities. Oily wastes residual ash samples were collected from six treatment sites, each divided into four replicates in a Completely Randomized Design. A total of twenty-four residual ash samples were collected and taken to National Oil Spill Detection and Response Agency (NOSDRA) Reference Laboratory, Port Harcourt for extraction. The concentration of TPH, PAH and heavy metals in untreated hydrocarbon wastes were also determined and used for the control experiment. The extracts were analyzed using AGILENT 7890A-GC and Atomic Absorption Spectrophotometer (AAS) modelled 240FS, manufactured in USA. The results show six residual pollutants;Cadmium, Lead, Zinc, Manganese, TPH and PAH below the Nigeria Department of Petroleum Resources (DPR) Intervention Level but exceeded the DPR Target Level for TPH and PAH. The descending order of concentration of PAH obtained from the treatment sites gwere;1.24 + 2.4 mg/kg (Paschal), 4.76 + 7.48 mg/kg (ITS), 10.46 + 14.68 mg/kg (TMCH) and 16.14 + 6.36 mg/kg (Mosab). Similarly, the concentration of TPH was 320.18 + 355.13 mg/kg (TMCH), 463.25 + 205.29 mg/kg (ICREN) and 501.11 + 300.79 mg/kg (Networld) against TPH 12,000 mg/kg, PAH 23 mg/kg, Cadmium 0.15 mg/kg, Lead 0.59 mg/kg, Zinc 3.45 mg/kg and Manganese 2.8 mg/kg (untreated wastes). Two treatment sites only recorded concentration of heavy metals, while four reformed inefficiently and couldn’t detect the concentration of some residual pollutants in the ash samples and consequently, recorded below detectable level (BDL). Statistical analysis showed a significant difference (P 0.05) between heavy metal content across sites and their target values. The results showed that the remediation activities had a strong impact on the concentration of TPH and PAH, and a weak impact on the concentration of heavy metals in the treated oily wastes. The implications of the results are discussed.
