Seasonal Evaluation of Physicochemical Parameters, Heavy Metals Levels and Pollution Status in Leachate from Ikhueniro Open Solid Waste Dumpsite located in Benin City, Edo State, Nigeria

Abstract

In recent times, there is a rapid rate of growth in the cities of third-world countries. This rapid population growth has implications for municipal waste management. Hence, the objective of this work is seasonal evaluation of physicochemical parameters, heavy metals levels and pollution status in leachate from Ikhueniro open solid waste dumpsite located in Benin City, Edo State, Nigeria using standard methods. Data obtained reveals that the pH of leachate samples collected during the rainy and dry season was alkaline. Iron was the main heavy metal contaminant in the Ikhueniro dumpsite, with calculated contamination factors of discharged leachate estimated at 154.48 ± 3.56 and 167.38 ± 3.33 during rainy and dry seasons, respectively; while copper was the least heavy metal contaminant, as indicated by contamination factors of discharged leachate reported as 3.22 ± 0.04 and 14.15 ± 2.00 during rainy and dry seasons, respectively. The increasing order of contamination of the dumpsite with the analyzed heavy metals was as follows: Cu<Cr<Zn<Hg<Pb=Ni<Cd<Fe for rainy season and Cu<Cr<Zn<Ni<Hg<Pb<Cd<Fe for dry season. Heavy metal and other chemical contaminations were widespread in the examined samples due to poor waste management system at the Ikhueniro dumpsite; resulting in high levels of heavy metals above the limits set by regulatory agencies. The Ikhueniro dumpsite posed very high potential ecological risk during the rainy and dry seasons, respectively. Thus, there is urgent need to provide remediation systems that can help to significantly reduce concentrations of heavy metals and other toxicants from the dumpsite.

Keywords

• Open solid waste dumpsite; Heavy metals; Leachate; Ecological risk