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

Abstract

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 quality
both 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 State