Correlation patterns between magnetic parameters and heavy metals of core sediments in the Yellow River Estuary and their environmental implications

Abstract

The potential use of environmental magnetism to investigate heavy metal pollution was investigated by analyzing sediment samples from a short sediment core (Z07) from the Yellow River Estuary. The heavy metal concentrations and speciation, grain sizes, and magnetic properties were determined, and correlations between the parameters were identified. Strong exponential relationships were found between the Hg concentrations and χfd%, χARM-20mT, and clay content. Linear correlations were found between the As, Cd, Co, Cr, Ni, Pb, and Zn concentrations and χfd%, χARM-20mT, and clay content. This indicated that Hg was mainly sorbed to the surfaces of nano-sized magnetic and clay minerals and predominantly had anthropological sources but the other heavy metals had mineralogical and other natural sources. These conclusions were supported by the heavy metal fractionation results. Heavy metal concentrations in sediment at site Z07 have decreased markedly since 2003 in response to water and sediment regulations being implemented.