Browsing by Author "Opuene, K."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Identification of perylene in sediments: Occurrence and diagenetic evolution
    (International Journal Environmental Science Technology, 2007) Agbozu, I. E.; Opuene, K.; Iwuozor, C. C.
    Perylene and penta-aromatic hydrocarbons were determined in sediments as part of a study that was dedicated to the aquatic ecosystem of Elelenwo Creek (Southern Nigeria) in order to carry out a critical corroboration of occurrence and diagenetic evolution of perylene in the sediments of the creek. The results show that the annual mean levels of Benzo [g, h, i] Perylene ranged from 209.00 – 245.28 µg/kg dry weight at the various stations sampled. Meanwhile, Station 3 recorded the highest mean level of 245.28 µg/kg dry weight. The observed values for total penta-aromatic hydrocarbons were high (787.00 - 1154.36µg/kg dry weight) in all the stations sampled. In addition, the highest mean value of 1154.36µg/kg dry weight was again recorded at station 3 for the penta-aromatic hydrocarbons. One origin index or concentration ratio of Ip/Ip+BghiP was also used to evaluate the suitability of the penta-aromatic hydrocarbons as a tracer to distinguish between contaminations arising from different sources. The values for the sampling stations therefore ranged from 0.41 to 0.43. A critical appraisal of the PAH index, consequently, suggested that petroleum combustion is the major penta-aromatic hydrocarbon source in sediments of the creek. The PAH group profile shows that perylene was high in the sediments and would pose apparent effects in fauna. The high concentration of perylene in the sediments was also indicative of an in situ biogenic derivation. Furthermore, a concentration of perylene > 10 % of total penta-aromatic hydrocarbons established a credible diagenetic origin.
  • No Thumbnail Available
    Item
    Survey of heavy metals in the catfish Synodontis clarias
    (Int. J. Environ. Sci. Tech, 2007) Agbozu, I. E.; Ekweozor, I. K. E.; Opuene, K.
    Elevated levels of heavy metals in the catfish Synodontis clarias can be a good indication of pollution of an aquatic ecosystem due to anthropogenic influence. The concentrations of Zn, Cd, Pb, Mn and Ni were determined in Synodontis clarias caught along a section of Taylor Creek and its associated tributaries. Samples were collected bimonthly between July 1999 and June 2000 in five stations. The metals: Zn, Cd, Ni, Pb and Mn were recorded in appreciable quantities, signifying their bioavailability. The levels of Zn, Cd, Ni, Pb and Mn may have obvious health implications on the rural communities that depend on fish species as fish supplement in view of its rich protein content and its bio-economic value. Generally, the sources of the metals in the catfish appear to be point and diffuse which include rural and agricultural runoff sources in the catchments area. However, the presence of an oil industry activity (Etelebou oil field and flow station) in one of its tributaries appears to be the major point source of the metal pollutants.