Assessment of groundwater pollution near Aba-Eku municipal solid waste dumpsite
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Date
2019-10
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature : Environ Monit Assess
Abstract
Municipal solid waste (MSW) dumpsite constitutes
a major anthropogenic point source of leachate
contamination to the ambient groundwater and poses a
significant threat to the geo-ecosystem. This study investigated
the pollution of groundwater by leachate emanating
from Aba-Eku MSW dumpsite in Ibadan, Nigeria,
using bacteriological, hydrochemical, and geophysical
techniques. There is a diversity of bacteria in the leachate
and the dominant phyla being proteobacteria (83%) and
firmicutes (17%). The mean concentrations (mg/L) of
Mn, Fe, Al, Cu, Mo, and Cr in the leachate samples were
above the World Health Organization wastewater discharge
limits. The hydrochemical parameters of the
groundwater samples around the dumpsite were generally
within the permissible limits, except for K and Cl−;
which invariably indicate major inputs from water-rock
interaction and minor contributions from the dumpsite.
Three geoelectrical layers were indicated from the vertical
electrical sounding data, which are the topsoil, the
lateritic clay layer, and the weathered basement. Low
resistivity values of 5–33 Ωm and 3–24 Ωm were obtained
within 2mand 5.5mdepths for the topsoil and the
lateritic layer, respectively; while the 2-D subsurface
model reveals leachate plume beyond 5 m. Although
the MSW leachate is heterogeneous, the hydrochemical
data show that the aquifer around the dumpsite has not
been seriously polluted with the leachate, but there is a
continuous percolation of leachate into the soil subsurface,
based on the geophysical findings. Discontinuing
waste dumping and groundwater extraction, which
would over time reduce the leachate plume, aremeasures
to enhance the groundwater quality in the area.
Description
Staff Publication
Keywords
Municipal solid waste, Leachates, Aba- Eku, Soil subsurface, Nigeria