Improving the source apportionment method through temperature and attenuation correction for pharmaceuticals and personal care products in surface water.

Quantitatively identifying emission sources of pharmaceuticals and personal care products (PPCPs) is crucial for controlling PPCP contamination, and receptor models have been extensively applied in surface water for source apportionment. However, the resolution of receptor models is limited due to the neglect of indicator-PPCP characteristic variations in emission sources and receiving water. Herein, we propose a strategy to improve the method resolution via correction coefficients that elaborate on tunable variables reflecting climate impacts and in-stream attenuations. Temperature and attenuation correction coefficients were derived from functional correlations between environmental variables and spatiotemporal changes of indicator-PPCP characteristics, considering both emission sources and receiving water. The receptor model, equipped with correction coefficients, presented a more favorable agreement in verification results (59%-98%) with hypothetical samples, making this strategy helpful for more accurate source apportionment. The application of the optimized source apportionment method in Huangpu River revealed that contributions of livestock wastewater and domestic wastewater were 21%-40% lower in 2020 compared to 2015, suggesting the effectiveness of drainage upgrades and the elimination of faulty livestock farms. In tributaries, considerable proportions of domestic wastewater (37%-49%) were attributed to sewer overflows in old communities. The novel approach that discriminates the overlapping features in emission sources provides valuable insights for optimizing the performance of receptor models, helpful to conduct the PPCP pollution assessment in surface water and formulate the sustainable wastewater management strategy.