Interseasonal distribution and partitioning of heavy metals in subtidal sediment of Qua Iboe Estuary and associated Creeks, Niger Delta (Nigeria)

Abstract

An analysis of the distribution and chemical forms of selected metals: cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and lead (Pb) in subtidal sediments of Qua Iboe Estuary and adjourning creeks, collected between June 2000 and January 2001, were studied using a sequential chemical extraction method. The concentration of metals in each extracted fraction was determined using inductively coupled plasma spectrometer (ICP-AES). Pb, Cd and Cu appear to be the most abundant metal in the sediments of the systems, and are predominantly associated with the residual, organic and oxidisable phases. Results indicate that there are also insignificant components that are bound to both the exchangeable and carbonates fractions. Ni is largely associated with bioavailable phases with insignificant bound to organic matter and residual fractions. In general, an insignificant component of Cd and Pb are bound to organic matter phase. Moreover, speciation results indicate that metal contamination in the ecosystems investigated primarily comes from human-mediated sources. Thus, based on index of geoaccumulation calculated, sediments of these ecosystems have been classified as uncontaminated by Cr, Cu and Ni, strongly contaminated by Pb and extremely contaminated by Cd.

BIOSORPTION OF CD, CR, MN, AND PB FROM AQUEOUS SOLUTIONS BY Bacillus SP STRAINS ISOLATED FROM INDUSTRIAL WASTE ACTIVATE SLUDGE

“…The sequencing reactions were performed by LANGEBIO, Mexico. The obtained 16s rDNA sequences were aligned against nucleotide sequences from the GenBank [9] and the Ribosomal Database Project (RDP) [10] using the ClustalX2 method [11] . Sequencing reactions were performed by the Macrogen Korea Institute (Seoul, Republic of Korea) using the Sanger technique [12] .…”

Analytical Relevance of Trace Metal Speciation in Environmental and Biophysicochemical Systems

“…Studies have shown that the physicochemical forms of trace metals determine their potential bioavailability and remobilization in aquatic systems [1,11]. However, the chemical speciation of metals could be made possible by changing ecohydrological perturbations, or as the organic particulates binding the metals ultimately decompose [1,49]. Trace metals in different sequential extraction aside reflecting the metal component or integrity of an ecosystem could be used to realize the chemical behavior with respect to remobilization.…”

“…Trace metals are introduced anthropogenically as micropollutants into our environment from several sources such as industrial, agricultural and domestic wastewater/ effluents [1]. Over the years, their fate, transport and pollution in the environment especially the aquatic ecosystems are becoming an environmental problem of concern owing to their ecotoxic properties.…”

Trace Metal Contamination Characteristics and Health Risks Assessment ofCommelina africanaL. and Psammitic Sandflats in the Niger Delta, Nigeria

“…Pollution investigations in coastal ecosystems of Niger Delta have revealed that human mediated activities can adversely alter the ecological integrity of fragile aquatic systems in the region, resulting in bioaccumulation of chemical contaminants by zoobenthos [1][2][3][4], sediment enrichment [5], and impact on species abundance and biomass [6,7]. Most equatorial wetlands and ultisol systems in the Niger Delta serve as primary recipients of petroleum exploration-exploitation wastes and domestic and industrial wastes generated by multinational oil companies that are found in the region.…”