Mineral and elemental compositions of suspended particulate matter (SPM) and sediments from major rivers in the Southeastern Nigeria

Abstract

Mineral and elemental compositions of suspended particulate matter (SPM) and sediments from the Great Kwa, Calabar, Cross River, Imo, and Qua Iboe Rivers in southeastern Nigeria were assessed in this study. SPM samples were obtained by collecting water samples from the studied rivers and passing the water through dried and pre-weighed Whatman fiberglass filters, after which the retained sediments were dried to constant weight. Bottom sediment samples were collected using a Van Veen grab sampler, transported to the laboratory, and air-dried at room temperature for seven days.

The samples were analyzed using Energy Dispersive X-ray Analysis (EDX), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). EDX analysis revealed that high levels of silicon (Si) and aluminum (Al) were common in all studied samples. Silicate minerals were observed in all sediment samples. XRD analysis showed that quartz, clay minerals, micas, hornblende, potassium feldspars, and mafic minerals were the dominant minerals in both SPM and sediments. Quartz, gypsum, and gibbsite minerals were found in higher concentrations during high tide compared to low tide conditions.

SEM analysis identified zircon, amphibole, pyroxene, biotite, pyrite, and iron hydroxides in the samples. The mineralogical and elemental compositions of SPM and sediments from the studied rivers provided important information regarding the environmental condition and pollution status of these aquatic systems.