Tracing urban sewage pollution in Chaohu Lake (China) using linear alkylbenzenes (LABs) as a molecular marker

► Chaohu Lake was significantly affected by discharge of sewage. ► Inadequately treated sewage from urban region was identified as the main contributor. ► Homologue-selective degradation was not considered to be a good indicator of LABs. ► A negligible share of LABs from Chaohu Watershed was accumulated into bottom sediment.