Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. ► Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. ► HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. ► A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. ► The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.