[Spatial Distribution and Source Analysis of Heavy Metals in Multiple Environmental Media Around a Waste Incineration...

Heavy metals surrounding waste incineration plants undergo cross-media migration and enrich in the soil-water system, resulting in a systematic deterioration of the physical and chemical properties of the soil and posing potential hazards to the ecological environment and human health. Taking the heavy metals in the soil, sediment, surface water, and groundwater around a waste incineration plant in Jiangxi Province as the research objects, descriptive statistical analysis was conducted on the contents (or concentrations) of heavy metals in multi-media. The spatial distribution characteristics of heavy metals within the soil-water system were analyzed, and the sources of heavy metals in the soil were deciphered by comprehensively using correlation analysis and the Absolute Principal Component Analysis-Multiple Linear Regression (APCS-MLR) model. The results showed that heavy metals around the waste incineration plant were mainly enriched in the soil and sediments. The content of Cd in the soil exceeded the risk screening value, and the contents of Cd and Zn exceeded the soil background values in Jiangxi Province. The average values of As, Cr, Ni, Pb, and Zn in the sediments exceeded the sediment background values in Jiangxi Province. The concentrations of heavy metals As and Pb in the groundwater exceeded the groundwater standard (Class Ⅲ). The variation coefficients of As and Cd in the soil were 53.97% and 39.84%, respectively, which belonged to a strong variation degree and exhibited obvious characteristics of point source pollution. The average content of Zn in the soil samples was higher than that in the sediment samples, while the contents of As, Cd, Cr, Cu, Ni, and Pb in the sediments were higher than those in the soil. The results of the correlation analysis between the distance from the riverbank and the cumulative concentration of heavy metals indicated that the concentration of heavy metals in the groundwater was affected by the recharge of surface water. The contents of heavy metals As, Cd, Ni, and Pb in the soil were higher in the southeast wind direction, which was obviously affected by the perennial dominant wind direction of the waste incineration plant, while Cr, Cu, and Zn were not significantly affected by the wind direction. The contents (concentrations) of heavy metals in the sediments and surface water generally showed a trend of first increasing and then decreasing along the flow direction of the surface water. The contents (or concentrations) of the other six heavy metals except Cr were higher near the sewage outlet and in the lower reaches of the river, among which the influence of As was the most obvious, which may have been related to the industrial activities of the waste incineration plant. The heavy metals in the soil mainly came from industrial sources of waste incineration, agricultural sources of pesticides and fertilizers, and natural sources of parent materials, with corresponding contribution rates of 31.14%, 28.14%, and 40.72%, respectively. The industrial sources of waste incineration had different degrees of influence on the seven heavy metals. The influence on As and Cd was the most significant; the influence on Ni and Pb was general; and the influence on Cu, Cr, and Zn was relatively weak. Among them, As and Cd mainly came from industrial sources, Ni and Pb mainly came from industrial and natural sources, while Cu, Cr, and Zn mainly came from agricultural and natural sources. It can provide data support and scientific basis for comprehensively investigating the heavy metal pollution status of multi-media and developing strategies for the prevention and control of heavy metal pollution around waste incineration plants.