Here dissolved and adsorbed concentrations of twenty concerned PCB congeners and total PCBs have been measured in the centralized wastewater treatment plant of a chemical industry zone in Zhejiang, China.
It was found that the dyeing chemical processes were the main source of PCBs, which contributed more than 13.6%.
The most abundant PCB was PCB-11 in the liquid and solid phase of each treatment stage, accounting for more than 60% of the total 209 PCBs.
Partitioning behavior of PCBs between the dissolved and adsorbed phases suggested that Di-CBs were the dominant isomers (>70%) and more than 89.8% of them was adsorbed on the particles and sludge.
The total removal efficiency of ∑209 PCBs was only 23.2% throughout the whole treatment process.
A weak correlationwas obtained between the individual PCB concentration and their log