Chemistry-Scholarly Publications

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Browsing Chemistry-Scholarly Publications by Author "Achadu, O.J"

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  • Item
    Open Access
    Assessment of heavy metals (Pb, Cd, Zn and Cu) concentrations in soils along a major highway in Wukari, North-Eastern Nigeria
    (Journal of Biodiversity and Environmental Sciences (JBES), 2015-02-01) Achadu, O.J; Goler, E.E; Ayejuyo, O.O; Olaoye, O.O; Ochimana, O.I
    Heavy metal pollution is a major environmental problem, especially around highways with high traffic density. This study investigates the levels of Pb, Cd, Zn and Cu in roadside soils of Wukari section of the Wukari-Jalingo highway, Taraba state, Nigeria. Samples were randomly collected and analyzed using standard methods. The mean concentrations (μg/g) of Pb, Cd, Zn and Cu from all sample sites ranged: 89.6-247.0, 0.15-5.3, 26.8-163.0 and 7.1-61.2 respectively. The extent of the heavy metals contamination was assessed, as analytical data were subjected to pollution calculation methods. The contamination factors (CF) reveal extreme contamination of the sites and an increasing trend in the heavy metals concentrations was observed in sites with more human activities. The pollution load index (PLI) showed that the sites are severely polluted as the PLI of the metals from each sample site exceeded the PLI of the background (control) sample (0.7). Spearman’s rank correlation analysis showed clear correlations (p<0.001) amongst the metals suggesting a common source. It can be concluded that the study sites pollution is mostly due to automobile emissions. This study provides awareness for residents to avoid activities such as farming, trading etc very close to the highway due to exposures to these toxic metals.
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    Open Access
    The impact of gas flaring and venting in Nigeria and management options: a case study of oil producing areas
    (Journal of Biodiversity and Environmental Sciences (JBES), 2014-02-03) Ayejuyo, O.O; Biobaku, C.B; Osundiya, M.O; Achadu, O.J
    This study assesses gas flaring and venting impacts in some oil producing areas in the Niger-Delta of Nigeria. The research instrument adopted for this study was the questionnaire survey and laboratory analysis, both microbiological and physico-chemical. The analysis of the data was done using simple descriptive analysis of frequency distribution of the relevant statistical information, supplemented by Chi-Square (X2) statistical method. Soil samples obtained from selected flare sites were analyzed and they indicated a negative impact on the microbial content of the soil. Rain water samples collected from different locations at different times and analyzed revealed a significant level of acidity (4.5-6.9) which causes damage to property and affect crops yield. Nitrates produced by the gas flare which varied from 0.12 to 0.47 mg/L result in the production of dilute nitric acid which is also corrosive. A survey carried out in this study revealed that the majority of Nigerians believe that gas flaring and venting has negatively impacted human health and the environment mainly in the oil producing areas.
  • Item
    Open Access
    Synchronous Adsorption of Cadmium and Lead ions from Aqueous Media by Rice Husk Ash and Sodium Dodecyl Sulfate Combination
    (International Journal of Modern Analytical and Separation Sciences, 2014-02-28) Achadu, O.J; Ayejuyo, O.O; Ako, F.E; Dalla, C.L; Olaoye, O.O
    In this study, the synchronous removal of Pb2+ and Cd2+ ions from aqueous solutions by colloidal particles made from rice husk ash (RHA) in aqueous sodium dodecyl sulfate (SDS) solution was investigated. The RHA derived from rice husk waste generated from the rice mills in Wukari, north-eastern Nigeria was combined with sodium dodecyl sulfate (SDS) for the metal ions adsorption. The adsorption studies under different experimental conditions were optimized and the removal of Pb2+ and Cd2+ ions was highly pH dependent. The results indicated that pH 8.0 was the optimum for the removal of the metal ions. Adsorption equilibration time was achieved in 2 hours with maximum removal efficiency of the metals ions attained at 71.8 and 88.9 % for Pb2+ and Cd2+ respectively. The equilibrium data were satisfactorily fitted to Langmuir and Freudlich isotherms. The Langmuir isotherm models gave a better representation of the data than the Freudlich isotherms. The RHA-SDS combination showed higher adsorption capacity for Cd2+ ion compared to Pb2+ ion under the experimental conditions in the single and binary solutions. The study showed that RHA-SDS synergy can be effectively used for the removal of Pb2+ and Cd2+ ions from wastewater with higher efficiency compared to the use of RHA alone.