Polychlorinated Biphenyls in the Centralized Wastewater Treatment Plant in a Chemical Industry Zone: Source, Distribution, and Removal

Table 3

The concentrations (means ± SD) of PCBs in SPM and sludge of each treatment stage at the WWTP.

PCBs; (ng/g, dw)	SPM in RW	PSS	SPM in AHE	AS	HCS	FS
Indicator PCB congener
PCB-28	100.5 ± 21.2	266.6 ± 63.6	316.7 ± 82	255.8 ± 89.1	87.36 ± 32.5	1317.1 ± 158
PCB-52	6.289 ± 2.83	17.3 ± 7.1	19.75 ± 7.07	22.41 ± 9.90	7.85 ± 1.74	26.4 ± 15.1
PCB-101	0.139 ± 0.04	0.357 ± 0.04	0.437 ± 0.07	0.377 ± 0.09	1 ± 0.042	3.101 ± 0.17
PCB-118	0.416 ± 0.07	1.17 ± 0.08	1.365 ± 0.11	1.665 ± 0.14	0.204 ± 0.08	2.763 ± 0.29
PCB-138	0.243 ± 0.05	0.698 ± 0.06	0.869 ± 0.14	0.903 ± 0.32	0.29 ± 0.06	3.002 ± 0.51
PCB-153	0.394 ± 0.06	1.013 ± 0.07	1.362 ± 0.31	1.829 ± 0.49	0.307 ± 0.07	2.893 ± 0.73
PCB-180	0.032 ± 0.01	0.063 ± 0.03	0.087 ± 0.07	0.108 ± 0.12	0.033 ± 0.03	0.282 ± 0.20
Sum Ind	108.0 ± 18.5	287.2 ± 56.7	340.5 ± 89.8	283.1 ± 100	97.05 ± 34.5	1355.6 ± 175
Dioxin-like PCB congener
PCB-77	4.835 ± 0.57	12.84 ± 6.22	14.81 ± 7.14	15.02 ± 8.63	4.85 ± 2.02	20.15 ± 13.8
PCB-81	0.027 ± 0.01	0.043 ± 0.03	0.057 ± 0.04	0.064 ± 0.06	0.02 ± 0.01	0.119 ± 0.09
PCB-105	0.137 ± 0.03	0.404 ± 0.05	0.463 ± 0.07	0.519 ± 0.09	0.119 ± 0.05	1.345 ± 0.18
PCB-114	0.01 ± 0.004	3.1 ± 1.3	0.026 ± 0.01	0.076 ± 0.04	0.015 ± 0.01	0.112 ± 0.08
PCB-123	0.002 ± 0.001	2.9 ± 1.4	0.014 ± 0.01	0.08 ± 0.01	0.064 ± 0.004	0.368 ± 0.19
PCB-126	ND	ND	0.012 ± 0.01	0.033 ± 0.03	0.012 ± 0.001	0.242 ± 0.04
PCB-156	ND	4.8 ± 1.1	0.014 ± 0.01	0.095 ± 0.04	0.026 ± 0.001	0.859 ± 0.06
PCB-167	0.204 ± 0.006	7.3 ± 4.2	0.643 ± 0.05	0.496 ± 0.06	0.352 ± 0.02	0.648 ± 0.11
PCB-169	ND	ND	0.042 ± 0.02	0.086 ± 0.04	0.025 ± 0.034	0.103 ± 0.10
PCB-189	0.038 ± 0.008	ND	0.101 ± 0.06	0.173 ± 0.09	0.105 ± 0.047	0.257 ± 0.18
Sum DL	5.254 ± 0.55	126.8 ± 29.4	16.19 ± 7.44	16.64 ± 8.83	5.59 ± 2.207	24.2 ± 14.7
Other PCB congener
PCB-11	803.23 ± 212	10191.4 ± 552	2702.4 ± 655	3066.8 ± 744	1135.5 ± 459	4478.4 ± 842
PCB-15	ND	105 ± 51	0.164 ± 0.02	0.217 ± 0.03	0.352 ± 0.11	0.235 ± 0.12
PCB-19	ND	4.9 ± 4.2	0.013 ± 0.01	0.025 ± 0.01	0.083 ± 0.037	0.038 ± 0.04
Mono-CBs	95.47 ± 35.35	642.7 ± 63.6	306.3 ± 61.6	320.1 ± 65.5	284.6 ± 45.9	510 ± 94.7
Di-CBs	1046.1 ± 311	12186 ± 992	2852.3 ± 726	3389.3 ± 800	1146.4 ± 527	4931 ± 1128
Tri-CBs	160.57 ± 46.67	425.3 ± 127	497.3 ± 109	219.5 ± 109	102.3 ± 51.2	862.4 ± 143
Tetra-CBs	17.151 ± 7.07	554.3 ± 141	51.62 ± 25.3	62.95 ± 27.9	24.17 ± 14.7	78.82 ± 36.2
Penta-CBs	1.875 ± 0.007	158.9 ± 73.5	6.324 ± 1.6	10.87 ± 3.34	12.85 ± 0.99	6.886 ± 3.68
Hexa-CBs	1.572 ± 0.848	197.4 ± 113	6.242 ± 1.23	8.965 ± 1.67	2.02 ± 0.848	12.31 ± 2.14
Hepta-CBs	0.78 ± 0.424	121.4 ± 21.2	3.485 ± 0.92	6.758 ± 1.51	1.359 ± 0.424	11.63 ± 1.65
Octa-CBs	0.587 ± 0.283	191.9 ± 99	2.436 ± 0.61	4.744 ± 1.23	1.262 ± 0.28	5.11 ± 1.29
Nona-CBs	0.102 ± 0.01	46.1 ± 22.6	0.378 ± 0.03	7.057 ± 1.89	0.226 ± 0.14	8.77 ± 1.73
Deca-CBs	0.213 ± 0.007	16.5 ± 11.3	0.984 ± 0.55	3.109 ± 0.79	0.082 ± 0.31	5.485 ± 0.94
∑209 PCBs	1324.4 ± 306.9	14541 ± 1397	3727.4 ± 927	4033 ± 1014	1875.3 ± 641	6432 ± 1123
SS (mg/L)	450	1 ∗ 10^4	100	2 ∗ 10^3	1 ∗ 10^3	2 ∗ 10^4

SPM: suspended particulate matter; RW: mixing influent (raw wastewater); PSS: primary sedimentation sludge; AHE: anaerobic hydrolysis effluent; AS: activated sludge; HCS: high-density clarifier sludge; FS: final sludge; ND: not detected; sum Ind.: sum indicator PCBs; and sum DL: sun DL-PCBs.