Spatial distributions and historical sources of combustion organic carbons in Taihu Lake, China

COPs (combustion organic carbons) are a type of pollutant generated during fuel combustion, and the rapid accumulation of COPs in lake environments poses a serious threat to watershed climate change and lake ecological security. Taihu was used as the study area, and the concentrations of char in the surface sediments of Taihu were significantly higher than those of soot, with average concentrations of 2.2 and 0.5 mg kg^{− 1} respectively. In combination with ¹³⁷CS and ²¹⁰Pb dating technologies, the historical concentrations of COPs in Taihu have been reconstructed for the past century. The concentrations of all COPs have increased rapidly since the reform and opening up and have remained stable since approximately 2003, which is closely related to China’s industrial economic development and legal measures for environmental protection. Combined with the source apportionment receptor model, the contribution amount of each pollution source to the COPs in the sediment of Taihu in the past century was quantified. In the past hundred years, biomass sources have made relatively stable contributions to COPs in the Taihu Lake sediments. With the rapid development of social economy, the amount of petroleum fossil fuel combustion has increased year by year, and the COPs contributions to the Taihu Lake sediments have also increased rapidly in the past 40 years, becoming the main source of COP.