TITLE:
Assessment of the Concentration of Petroleum Hydrocarbon in Oily Wastes Residual Ash at Bodo-Ogoni Remediation Site, Nigeria
AUTHORS:
Tambeke Nornu Gbarakoro, Augustine Dan Bello
KEYWORDS:
Hydrocarbon Wastes, Permissible Limits, Oily Residual Ash, Treatment Sites, Remediation Activities, Heavy Metals
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.10 No.5,
May
9,
2022
ABSTRACT: 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.