Heavy Metals and Total Hydrocarbon Contents of Nypa fruticans Grown along the Shores of Qua Iboe River, Akwa Ibom State of Nigeria

Abstract

This study ascertains the amount of heavy metal and hydrocarbon content in an area exposed to crude oil exploration and exploitation activities. The study area is the Qua Iboe River in the Niger Delta region of Nigeria and the study samples were Nypa palm (Nypa fruticans) leaves obtained along the shores of the river. The concentration of Pb, Cd, Cu and Ni in the leaves were determined using the Atomic Absorption Spectrophotometer while Total Hydrocarbon Content was determined using Gas Chromatography, coupled with the flame ionization detector (GC-FID). Results obtained showed that in site I, Pb mean concentration was 1.068±0.014 mg/kg, Cd (0.017±0.003 mg/kg), Cu (2.390±0.204 mg/kg), Ni (0.012±0.001 mg/kg) and THC (124.361.7± 1120.502 mg/kg) while for site II: Pb (1.076±0.025 mg/kg), Cd (0.028±0.003 mg/kg) Cu (0.037±0.007 mg/kg) Ni (2.049±0.024 mg/kg) and THC (311,813.4± 2950.291 mg/kg). Heavy metal concentration in the study sites were largely within the WHO permissible limits with the exception of Cd in site II. Generally, the amount of heavy metals and THC were higher in the study sites than in the control site, which was an area with negligent oil exploitation and industrial activities. Therefore, the elevated concentration of heavy metals and THC in the study sites may be attributed to the various industrial activities sited in the area.

Comparison of Investigated Levels of Physicochemical Parameters in Qua Iboe River, Oruk Anam, Nigeria with Portable Water Standards

“…On the pH scale, pH of 7.0 indicates a neutral solution, pH values smaller than 7.0 indicate acidity, pH values larger than 7.0 indicate alkalinity. The mean levels of pH in this study were consistent with levels reported by [2,12] and agreed with standards of 6.5 -8.5 set up WHO, USPH and NSDWQ.…”

“…Comparatively, higher levels were recorded in dry season than wet season in all locations and could be ascribed to dilution and concentration effects of the volume of water in wet and dry seasons respectively. Levels recorded across all sampling locations were lower than levels reported by [10] but were consistent with levels reported by [12] In general, levels recorded in this study were below maximum limits of 250µS/cm recommended for drinking water by WHO and other regulatory bodies.…”

“…The solution was then titrated with 0.025 M sodium thiosulphate (Na2S2O3. 5H2O) solution until the colour changed from blue to colourless indicating end point'' [1,15,12]. The level of DO in the sample was obtained using Equation 1.…”

“…Permissible limits of DO in aquatic ecosystem capable of supporting aquatic life fall between 8 -10 mg/L as given by WHO [10,9]. ''Total dissolved solid (TDS) is a parameter that influences the taste of water'' [11,5,12]. ''Total hardness is imparted to water quality due to the presence of calcium and magnesium ions.…”

“…Other physicochemical parameters such as electrical conductivity, turbidity, alkalinity also have negative effects on aquatic organisms and plants at elevated levels. ''Researchers have revealed that elevated levels of water quality parameters are known to results from tremendous anthropogenic activities such as agriculture, lumbering, road construction, fishing, transportation of all forms, automobile works, establishment of numerous upstream and downstream industries among others leading to an interference in ecological balance of these parameters in aquatic ecosystems'' [5,12,14].…”