[Source Apportionment and Input Flux Analysis of Heavy Metals in Soils Surrounding Coal Gangue Heap Based on Receptor...

This study focuses on the soils surrounding coal gangue heap in Chongqing Municipality, considering potential pollution sources such as atmospheric deposition, fertilizers, pesticides, and irrigation water. An emission inventory model was employed to analyze the input fluxes of heavy metals, which was further combined with the absolute principal component scores-multiple linear regression (APCS-MLR) receptor model to quantitatively trace the sources of soil heavy metals. Surface and profile soil data revealed that the concentrations of Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn in the study area were influenced by varying degrees of anthropogenic activities. Spatial distribution analysis showed that Cd, Hg, As, and Pb exhibited similar distribution patterns, while Cu, Zn, and Ni displayed comparable spatial distributions. The results from the emission inventory model indicated that the input fluxes of Cd, Hg, As, Pb, and Cr were primarily attributed to irrigation water and atmospheric deposition affected by coal gangue heap, with contribution rates of 92.5%, 67.3%, 54.5%, 58.1%, and 70.2%, respectively. In contrast, Cu, Zn, and Ni inputs were mainly sourced from fertilizers and pesticides, contributing 78.5%, 92.8%, and 55.2%, respectively. The APCS-MLR receptor model analysis further demonstrated that the study area was influenced by mining, agricultural, and natural sources, with respective contribution rates of 45.4%, 35.2%, and 19.5%. The integrated application of the emission inventory model and receptor model can elucidate the "source-pathway-sink" relationship of soil heavy metal pollution more clearly and also render the source apportionment results more comprehensive, accurate, and reliable.