The adsorbed PCB isomers in secondary sedimentation effluent were absolutely predominant, varying between 87.3% for
Octa-CBs and 99.8% for Mono-CBs. Likewise, significant adsorbed fractions of PCB isomers were also found in the raw wastewater, primary sedimentation effluent, and anaerobic
hydrolysis effluent, varying between 53.4% for Nona-CBs and 99.1% for Tri-CBs, 54.0% for Nona-CBs and 99.4% for TriCBs and 45.9% for Nona-CBs and 98.3% for Mono-CBs, respectively. Differently, in high-density clarifier effluent,
Nona-CBs and Deca-CBs were more “dissolved” amon gthe PCB isomers, with only 30.0% and 39.2% in the solid phase, although the adsorbed fractions of other PCB isomers were all above 65% in this stage