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Coal mining activities have been ongoing in Okaba for years without adequate attention paid to pollution and reclamation. Soil and plants were sampled from Okaba coal mine to determine the metal content in the soil and to identify the plants that have potential for phytoremediation. The samples were prepared, separated into various tissues, and labeled and taken to the laboratory. Digestion was carried out using acid mixture of nitric acid (HNO3): perchloric acid (HCLO4) for the plants, while the mixture of nitric acid (HNO3): hydrochloric acid (HCl): perchloric acid (HCLO4) was used for the soil. The concentrations of metals from the samples were determined using EDX3600B X-ray fluorescence spectrometer (Sky ray Instruments Inc., USA), a World Bank Assisted Project, Nigeria. Bioconcentration factor (BCF), translocation factor (TF), and bioaccumulation coefficient (BAC) or extraction coefficient (EC) were determined to identify the plants that have potential for hyperaccumulation, phytoextraction, and phytostabilization and ability to store up these metals for harvesting. Hierarchical cluster analysis was performed to highlight the relationship between the variables. This study has revealed that Ageratum conyzoides Linn (ACL), Desmodium velutinum (DV), Triumfetta rhiomdoidea Jacq. (TRJ), Gleichenia linearis (Burns) (GL), Selaginella myosurus (SM), and Sida linifolia juss.excav. (SL) had potential as hyperaccumulators of nickel. Eleven (11) plants have potential for phytoextraction of manganese (Mn), and six (6) plants have stabilization potential for the same metal. Eight (8) phytoextractors and seven (7) stabilizers plants were recorded for Ni. Eclipta alba (L) Hassk (EAH) (location 4) and TRJ were phytostabilizers plants for Pb. Six (6) other plants have potential as phytoextractors of Pb. Eight (8) of the studied plants were suitable for phytoextraction of Ni, and five (5) plants were suitable as phytostabilizers. Most of the plants were found to be useful for phytoremediation of the soil. [ABSTRACT FROM AUTHOR]

Polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in groundwater and leachate around selected waste dumpsites from two southwestern states of Nigeria were investigated. Samples were Soxhlet-extracted using hexane/methylene chloride mixture and cleaned-up with preconditioned solid-phase extraction cartridges. The ∑PAHs (PCBs) (all in µg/L) in the boreholes, leachate, and hand-dug well across all locations ranged from below detection limit (BDL) to 0.62 (BDL to 0.067), 1.16 to 9.96 (0.003 to 0.041), and BDL to 0.01 (0.001–0.031), respectively. Low molecular weight-PAHs accounted for ≥61% of ∑PAHs detected across all locations. The highly chlorinated hexa-PCBs [2,2′,3,4,4′,5′-HeCB(#180), 2,2′,3,4′,5′,6-HeCB(#34) and 2,2′,4,4′,5,5′-HeCB(#153)] dominated the entire congener profiles. Pyrene and 2,3′,4,4′,5-PeCB(#118) constituted 56% and 58% of the ∑PAHs and ∑PCBs, respectively. Sampled water is not adequately safe for drinking and may pose cancer risk. This study should be sustained for health risk and sustenance of an enduring ecological integrity. [ABSTRACT FROM AUTHOR]