Evaluation and analysis of heavy metals in iron and steel industrial area

Heavy metal pollution has attracted more attention due to the toxicity and migration characteristics, which has close relationship with soil environment and food safety. Typical heavy metal pollutants, copper, lead, zinc, cadmium, chromium, nickel, arsenic and mercury, have been investigated in Jinan Steel Plant located in Jinan, Shandong Province, People’s Republic of China. The indexes of Nemerow, geo-accumulation, and potential ecological risk were applied to evaluate the soil pollution. Spatial distribution and vertical migration characteristics were also detected and analyzed. The pollution is mainly concentrated in (1) coke processing plant, (2) blast furnace and (3) stock area. According to the concentration index, Zn and Cr were selected as main pollutants; however, Hg and Pb play directly and indirectly roles in soil pollution based on evaluation system. The analysis in vertical direction indicated that heavy metals showed a certain migration and transformation ability. Moreover, heavy metals predominately existed in the residual fraction on the surface and the middle profile. The bioavailable fraction of Pb and Hg accounts relatively higher proportion, which could threaten human health along the food chain. In the process of heavy metal pollution evaluation and analysis, we should not only pay attention to high concentrations of heavy metals, but also focus on heavy metals with high toxicity and strong migration-transformation capability, which need real-time monitoring and assessment.