Chemical Speciation of some Heavy Metals in Sand Filter Media [SFM] Waste Dumpsite in Yenagoa, Nigeria

The chemical speciation of five heavy metals [HMs] in spent sand-filter-media [SFM] waste dumpsite was investigated with a view to ascertain their distribution and chemical availability of the heavy metals in the dumpsite. Samples were collected at the surface, 100cm depth of the dumpsite and 100m away from the dumpsite and analysed using FAAS for total concentration of Cr, Fe, Mn. Ni and Pb. Speciation analysis was carried out usingmodified Tessier’s sequential extraction method. The percentage concentrations showed that Pb occurred more at the exchangeable fraction with 90.6% at the top, 91.34% at 100cm depth. This signifies that Pb is biochemically available for in-take by living organisms. Fe had the highest concentration by mass 12mg/g but its occurrence of between 22- 28% is in the residual/inert fraction. Ni had 40% in the exchangeable and  carbonate fractions at the surface and at 100cm depth. Cr had highest exchangeable fraction of 46.29% and 45.59% at the surface and 100cm depth of the SFM. Mn had 37.30% and 42.26% at the surface and at 100cm depth of the SFM. Although Fe had highest concentration by mass, it is least biochemically available occurring more at the residual/inert fraction while the other four metals [Pb, Ni, Cr, Mn] are all biochemically available for intake by organisms and may enhance biochemical accumulation overtime and finally become harmful to living organisms around that dumpsite. Keywords: Speciation, Heavy metals, Sand Filter Media, Waste Dumpsit

Contamination and Pollution Studies of Heavy Metals in Sand Filter Media Waste Dumpsite in Yenagoa, Bayelsa State, Nigeria

The contamination and pollution level of five Heavy Metals in spent Sand Filter Media [SFM] waste dumpsite was investigated to ascertain the contamination, pollution and possible migration in that environment. Samples were collected at the surface, 0.1m depth and 100m away from the dumpsite and analysed using Flame Atomic Absorption Spectrophotometer (FAAS) for concentration of Cr, Fe, Mn. Ni and Pb ions. Geochemical Pollution Indices were used to evaluate the contamination and pollution level of the HMs comparatively using the world shale average values and the experimental control value. Results obtained showed highest concentration of 12.50mg/kg for Fe and lowest detectable concentration of 0.2mg/kg for Ni at the top of the dumpsite. All five heavy metals had low concentrations compared to WHO and national standards for soil qualityboth at the top and 0.1m depth of the dumpsite. Percentage concentrations of the heavy metals at the top showed 78.81, 12.04, 7.88, 1.26% in the order Fe >>> Cr > Mn > Ni > Pb with the values of Ni and Cr at 0.1m depth slightly higher indicating some level of migration. Contamination Factor Cf, depicts very severe contamination to slight pollution at the top with minimum of 0.714 and maximum of 1.471. Degree of Contamination Cd, of <8 and Modified Degree of Contamination mCd <1.5 showed low contamination. The pollution load index, PLI values of < 50 depicts that no drastic rectification measure was needed which concludes that the SFM dumpsite was contaminated but technically not polluted. Keywords: Surface mobility, Yenagoa, heavy metal contamination, Pollution indices, Bayelsa Stat

Characterization of chitosan from Rhynchophorus phoenicis and synthesis of its alumina nanocomposite

Rhynchophorus phoenicis, found in the tropical regions of Africa where it is regarded as a pest was used to synthesize chitosan and alumina-chitosan nano-composite. The synthesized Chitosan and alumina-chitosan nano-composite were characterized using instrumental methods of analysis which include Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM). FTIR reveals the existence of OH stretching vibration –NH stretching, NH bonding, vibration of methylene C-H bonding, O=C=O stretching, C-N bonding stretching and CO stretching vibration at 3842.33 cm-1, 3402.54 cm-1, 3286.81 cm-1, 2939.61 cm-1, 1527.67 cm-1, 1303.92 cm-1 and 1041.60 cm-1 respectively. The scanning electron micrograph proves that the chitosan has large particles that are regular with paltry pores while alumina-chitosan nano-composite has fairly small particles and porous surface with significant pores. X-ray diffractogram showed a distinct stretch at 22o; 16o and 25o; 17o for chitosan and alumina-chitosan nano-composite. The characterization of the products confirmed that the synthesis of chitosan and alumina-chitosan nano-composiote was effective