Source Identification of Polycyclic Aromatic Hydrocarbons in Water at Point of Effluent Discharge into the New Calabar River, Port Harcourt, Rivers State, Nigeria

Water samples from effluents discharge points were analyzed for polycyclic aromatic hydrocarbons (PAHs) concentration using chromatographic techniques. The result obtained showed the presence of all the PAHs categories in the water samples. The total concentrations of PAHs in the different location showed that Minipiti station was the highest (44.99 mg/L), which was followed by the values obtained at the Police Post station (36.89 mg/L) and finally, the lowest value was obtained at the Iwofe Jetty station (11.923 mg/L). Diagnostic analysis of the concentrations of the different PAHS concentrations based on the ratio of low molecular weight PAHs to high molecular weight PAHs (LMW/HMW), anthracene / anthracene + phenanthrene {An/(An + Phe)} fluoranthene/ fluoranthene + pyrene {Fl /(Fl + Pyr} and benzo[a] anthracene/ benzo[a]anthracene + chrysene {BaA/ (BaA + Chr)} showed the predominance of pyrogenic PAHs over petrogenic PAHs. Thus indicating more of human input sources than natural. Ring size analysis indicated the predominance of the higher molecular weights (4-6) rings over the lower molecular weights (2-3) rings. The implications of the high level of PAHs within the sampled environment should give warning signals to the user of the water environment’.

Quantal Response of Periwinkle (Tympanotonus fuscatus) after Exposure to Kerosene.

Periwinkles (Tympanotonus fuscatus) handpicked from the New Calabar River were acclimated to laboratory conditions in the research laboratory of the Chemistry Department of the Ignatius Ajuru University of Education, Rumuolumeni, Port Harcourt. They were subjected to concentrations (60, 90, 120, 150 and 200 ml/L) of a petroleum product, kerosene and a control to examine the effect of acute exposure on mortality of the periwinkles. The mean mortality of the periwinkles increasing with the concentration of the kerosene and the exposure time. The mean lethal concentration (96 hr LC50) of the kerosene was 111.14 ml/L, while the 96 hr LC99 was 433.94 ml/L and the probit equation at that hour, Y= -0.80 + 0.007X was significant. The mean lethal time (MLT50) at 60, 90, 120, 150 and 200 ml/L with the associated confidence limits were 90.13 (52.94–126.45), 84.06 (61.40–110.50), 79.02 (42.00–105.06), 73.27 (40.74–96.30) and 70.17 (39.84–94.20) ml/L respectively. The data obtained from the laboratory is an indication that kerosene is toxic to periwinkles which can be extrapolated to field conditions in the event of a spill.