Determination of Individual Magnetic Particle Sources in Sediments from the Wae Tomu River Estuary, Ambon City, Indonesia: Scanning Electron Microscope (SEM) and Energy-Dispersive X-Ray Spectroscope (EDX) Analysis

Abstract

This paper describes the determination of individual magnetic particle sources found in the sediment of the Wae Tomu river estuary in Ambon City, Indonesia. The sample used was a magnetic particle extracted from the sediment. As comparative data, magnetic particles were also extracted from the soil in the river upstream. These particles were characterized using a scanning electron microscope (SEM), energy-dispersive X-ray spectroscope (EDX), and X-ray diffraction (XRD). SEM analysis results showed that the magnetic particles found in the sediment have a spherule-shaped and framboid-like surface morphology measuring ≈43–97 mm, while magnetic particles found in the soil were octahedral and angular-shaped with a maximum length of ≈40–60 mm. The majority of the elemental composition of the magnetic particles from the sediment were Fe and O, followed by minor elements of Zn, Cu, S, Al, Si, and Cr. In contrast, the majority of elements from the soil were Fe and O, followed by minor elements of Ti, Al, and Mg. The X-ray Diffraction (XRD) analysis results show that the magnetic particles of the sediment are chromite and magnesite, while the soil is magnetite. Based on the morphological characteristics and elemental composition, the magnetic particles from the sediment originated from anthropogenic sources, i.e., motor vehicle emissions. In addition, SEM and EDX can be used to distinguish individual magnetic particles from anthropogenic and natural sources.