Source apportionment of phenolic compounds based on a simultaneous monitoring of surface water and emission sources: A case study in a typical region adjacent to Taihu Lake watershed.

A comprehensive characterisation of four phenolic compounds in surface water and various emission sources was conducted simultaneously in a typical industrial city upstream of the Taihu Lake watershed. The overall concentrations of the target compounds ranged from 0.15 to 2.75 μg/L in the surface water and from 0.43 to 377 μg/L in the emission sources. Relatively high concentration levels were observed in August, during which the rainy season typically occurred in the study area, indicating seasonal emission sources. The spatial distribution revealed severe phenolic-compound contamination in the northeast part of the study area. According to the relationships between the surface water and emission sources, combined-sewer overflow and surface runoff from agricultural activities were identified as seasonal emission sources that were responsible for the increased concentration levels in wet seasons. Indirect discharge of industrial wastewater was proposed as a persistent emission source responsible for the severe contamination level in the northeast region over the entire sampling period, accounting for 16.5% of the phenolic-compound load in a demonstration river section. The findings of this study are useful for identifying the sources of phenolic compounds and controlling the contamination from the main sources in a typical industrial city.