Investigations of Metal Pollution in Road Dust of Steel Industrial Area and Application of Magnetic Separation

Abstract

Pollution characteristics and ecological risks for metals in non-magnetic and magnetic road dust from steel industrial areas were investigated by applying a magnetic separation method. Metal (except for Al, Li, Ti, As, and Sb) concentrations in the magnetic road dust were 1.2 (Sn) to 7.8 (Fe) times higher than those in the non-magnetic road dust. For the magnetic road dust, the geo-accumulation index revealed a strongly to extremely polluted status for Cr, Zn, Cd, and Sb, a strongly polluted status for Mn, Cu, and Pb, and a moderately to strongly polluted status for Fe, Ni, Mo, and Hg. This result indicates that the dominant metal pollution sources of road dust in industrial areas were the traffic activities of heavy-duty vehicles. The mean content of magnetic particles accounted for 44.7% of the total road dust. The metal loadings in the magnetic road dust were 86% (Fe), 77% (Cr), 67% (Mn), 86% (Ni), 76% (Cu), 72% (Zn), 64% (Mo), and 62% (Cd), respectively. Removal of the magnetic fraction from road dust using magnetic separation techniques not only reduces metal contamination but can also improve effective road cleaning strategies or reduce waste generation.

A review on the clean-up technologies for heavy metal ions contaminated soil samples

“…Jeong et al, (2021) used the magnetic separation method for cleanup of metals viz. Cu, Zn, Cd, Ni, Cr, and Mn from road dust industrial areas [ 81 ]. It not only reduced the metal contaminants from the industrial area but also reduces waste generation.…”

Pollution and Health Risk Assessments of Potentially Toxic Elements in the Fine-Grained Particles (10–63 µm and <10 µm) in Road Dust from Apia City, Samoa

“…Cr is widely used in many industries, including metallurgy, steel manufacturing, automobile industry, electroplating, and wood preservation, because of its anticorrosive properties [58][59][60][61]. Cr is highly mobile and has extremely toxic effects even at very low concentrations; it is classified as a Group A carcinogen element in humans [62].…”

Reaction Behavior and Transformation Path of Zinc in the Heating-Up Zone during Sintering Process

“…Accordingly, controlling the zinc content of the sinter is particularly important [11][12][13][14][15]. Previous studies have shown that the zinc in sintering raw materials was mainly ZnS in iron ore and ZnO or zinc ferrite in secondary resources, ZnS was oxidized to form zinc oxide and sulfate in sintering production, and a very strong reducing atmosphere was needed to reduce and remove zinc when its content was high [16][17][18][19]. The main mineral phases in the sinter with ZnO added were magnetite, calcium ferrite (SFCA), silicate and zinc ferrite [20].…”