Research Article
Polychlorinated Biphenyls in the Centralized Wastewater Treatment Plant in a Chemical Industry Zone: Source, Distribution, and Removal
Table 2
The concentrations (means ± SD) of PCBs in wastewater of each treatment stage at the WWTP.
| | PCBs (pg/L) | RW | PSE | AHE | SSE | HCE |
| | Indicator PCB congener | | PCB-28 | 173.5 ± 76.4 | 163.2 ± 63.6 | 603.3 ± 56.6 | 237.4 ± 60.8 | 93.9 ± 49.5 | | PCB-52 | 249.1 ± 32.5 | 131.2 ± 32.5 | 178.1 ± 28.3 | 54.3 ± 25.4 | 31.6 ± 21.2 | | PCB-101 | 5.3 ± 1.8 | 5.3 ± 1.7 | 2.1 ± 1.4 | 1.6 ± 1.4 | 1.1 ± 0.7 | | PCB-118 | 48.7 ± 22.6 | 24.7 ± 8.5 | 29.6 ± 7.1 | 8.1 ± 5.6 | 6 ± 4.2 | | PCB-138 | 61.5 ± 21.2 | 34.5 ± 14.1 | 18.4 ± 7.2 | 10.7 ± 7.1 | 6.1 ± 4.2 | | PCB-153 | 89 ± 25.4 | 55.8 ± 22.1 | 39 ± 14.1 | 12.9 ± 8.5 | 8.6 ± 3.4 | | PCB-180 | 3.1 ± 0.8 | 2 ± 1.4 | 2.5 ± 1.4 | 2.3 ± 1.4 | ND | | Sum indicator PCBs | 630.2 ± 64.9 | 416.7 ± 35.6 | 873 ± 39.6 | 327.3 ± 79.2 | 147.3 ± 75.7 |
| | Dioxin-like PCB congener | | PCB-77 | 114.4 ± 42.2 | 93.7 ± 33.9 | 142.7 ± 32.5 | 52.2 ± 28.3 | 8.8 ± 5.6 | | PCB-81 | 0.13 ± 0.1 | 4.1 ± 1.4 | 3.9 ± 1.6 | ND | ND | | PCB-105 | 18.6 ± 7.1 | 10.9 ± 5.6 | 13.3 ± 4.2 | 3 ± 2.8 | 1.7 ± 1.4 | | PCB-114 | 0.45 ± 0.1 | 3.1 ± 1.3 | 2.2 ± 1.3 | 1.7 ± 1.4 | 1.4 ± 1.4 | | PCB-123 | 7.9 ± 1.4 | 2.9 ± 1.4 | 4.7 ± 1.4 | 3.9 ± 1.4 | 1.3 ± 1.4 | | PCB-126 | 1.9 ± 1.4 | ND | ND | ND | ND | | PCB-156 | 4.8 ± 1.4 | 4.8 ± 1.1 | 7.1 ± 2.5 | 1.5 ± 1.4 | 1.3 ± 1.2 | | PCB-167 | 13.8 ± 4.2 | 7.3 ± 4.2 | 6.4 ± 1.8 | 6.1 ± 2.8 |
1.1 ± 0.7 | | PCB-169 | 0.35 ± 0.3 | ND | ND | ND | ND | | PCB-189 | 0.4 ± 0.3 | ND | ND | ND | ND | | Sum DL-PCBs | 162.7 ± 33.3 | 126.8 ± 29.4 | 180.3 ± 29.0 | 68.4 ± 26.9 | 15.6 ± 3.5 |
| | Other PCB congener | | PCB-11 | 10321.6 ± 763 | 10191.4 ± 552 | 9931 ± 495 | 9944.3 ± 424 | 9479.1 ± 424 | | PCB-15 | 241.6 ± 84.8 | 105 ± 51 | 76.5 ± 42.4 | 31.2 ± 35.4 | 10.3 ± 8.5 | | PCB-19 | 7.1 ± 7.1 | 4.9 ± 4.2 | 4.6 ± 2.8 | 4.2 ± 2.8 | 3.2 ± 2.8 |
| | Mono-CBs | 831.4 ± 84.8 | 642.7 ± 63.6 | 512.4 ± 70.7 | 87.5 ± 70.7 | 43.6 ± 35.4 | | Di-CBs | 12233.10 ± 1004 | 12186.4 ± 992 | 11804.2 ± 735 | 11426.4 ± 665 | 11160.9 ± 566 | | Tri-CBs | 636.60 ± 169 | 425.3 ± 127 | 1182.2 ± 282 | 707.9 ± 254 | 348.6 ± 212 | | Tetra-CBs | 957.50 ± 141 | 554.3 ± 141 | 879.5 ± 141 | 302.9 ± 127 | 261.3 ± 107 | | Penta-CBs | 202.50 ± 84.8 | 158.9 ± 73.5 | 124.4 ± 73.5 | 74.1 ± 73.5 | 36.8 ± 31.3 | | Hexa-CBs | 342.10 ± 113 | 197.4 ± 113 | 152.7 ± 113 | 54.9 ± 28.3 | 27.1 ± 22.6 | | Hepta-CBs | 221.30 ± 21.2 | 121.4 ± 21.2 | 107.3 ± 21.2 | 67.3 ± 48.1 | 32.4 ± 32.5 | | Octa-CBs | 125.60 ± 21.2 | 191.9 ± 99 | 165.7 ± 84.8 | 89.6 ± 70.7 | 37.6 ± 21.2 | | Nona-CBs | 40.10 ± 32.5 | 46.1 ± 22.6 | 44.1 ± 19.8 | 58.3 ± 19.8 | 31.8 ± 14.1 | | Deca-CBs | 27 ± 18.4 | 16.5 ± 11.3 | 19.5 ± 8.5 | 16.8 ± 8.5 | 8.2 ± 8.5 |
| | PCBs | 15617.2 ± 1691 | 14540.9 ± 1397 | 14992 ± 618 | 12885.7 ± 659 | 11988.3 ± 510 |
| | SS (mg/L) | 450 | 120 | 100 | 30 | 12 |
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RW: raw wastewater (mixing influent); PSE: primary sedimentation effluent; AHE: anaerobic hydrolysis effluent; SSE: secondary sedimentation effluent; HCE: high-density clarifier effluent; and ND: not detected.
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