Assessment of heavy metal contamination in soil associated with Chinese coal-fired power plants: a case study in Xilingol, Inner Mongolia

The construction of coal-fired power plants (CFPPs) is an important issue in energy production and consumption, and regional sustainable development under Chinese 12th Five-Year Plan. Positively or negatively, the construction of CFPPs could affect ecological sustainability, sustainable development of cities and the surrounding areas, national energy security, and also the actions currently in place to curb air pollution. Specifically, CFFPs could create environmental hazards in the surrounding area, such as soil-related environmental problems as a serious consequence. The most significant soil-related environmental problems include the encroachment of farmland, soil erosion, and soil contamination by heavy metals. In this study, the CFPP in Xilingol, Inner Mongolia is used as an example. Ecological environmental data were collected, including details on heavy metal content in soil samples from the area. Based on these data, the potential ecological risk index was used to assess the level of soil pollution by heavy metals and ecological risks. For this CFPP in Xilingol, the heavy metal element has exhibited the highest level of soil contamination. The severity of ecological risk posed by different heavy metals was ranked in the following descending order: Hg>Cd>As>Ni>Pb>Cu>Cr>Zn.