Sorption of estrogens estrone, 17ß-estradiol, estriol, 17α-ethinylestradiol, and diethylstilbestrol on sediment affected by different origins.

The sorption coefficients of estrone (E1), 17ß-estradiol (E2), and estriol (E3), 17α-ethinylestradiol (EE2), and diethylstilbestrol (DES) on four sediments (BS1-4) collected downstream of agricultural, domestic, and industrial discharges were determined. The objective was to investigate the effect of sediment origin on the sorption affinity of natural and synthetic estrogens on sediments. Experimental results indicate that the sediment samples from different origins had differing estrogen sorption affinities. Organic materials in sediment samples collected from downstream of agricultural and domestic discharge, i.e., BS1 and BS2, respectively, were readily biodegraded and biotransformed during sediment diagenesis, which enhanced the sorption capacity for estrogens. Sediment samples BS3 and BS4, which were obtained downstream of domestic and industrial discharges, respectively, may contain complex compositions, including hydrophilic substances that resulted in lower log K(oc) values. The estrogen sorption on sediments was reasonably regressive with linear models. The log K(oc) values for individual estrogens in individual sediments showed variation: 2.82-4.21 for E1; 2.73-4.14 for E2; 2.19-3.76 for E3; 3.24-3.94 for EE2; and, 4.07-5.25 for DES. Nevertheless, the relationship between log K(ow) and log K(oc) of individual estrogens in individual sediments was linear. The mean log K(oc) values for target estrogens followed the trend of DES (4.68) > EE2 (3.71) > E2 (3.52) > E1 (3.44) > E3 (2.99), corresponding to the trend of log K(ow) values. These analytical results suggest that sorption of estrogens on sediments varied with sample origin. Therefore, evaluations of the fate and transport of estrogens in river environments must consider surrounding agricultural, domestic, and industrial sources.

PCBs in Donggang River Watershed sediments, Taiwan.

Polychlorinated biphenyls (PCBs) were measured in the sediments of the Donggang River Watershed, one of the most polluted bodies of water in southern Taiwan. Field data showed that detectable concentrations of 121 PCB congeners were found and total PCBs were measured in 32 out of 33 samples, and 98 congeners were detected. The total concentrations of PCBs in the sediment ranged from 25.5-63.5 ngg(-1) dw with a geometric mean ± standard deviation of 4.00 ± 1.73 ngg(-1) dw, with one sample below the detection limit. The highest concentration (20.79 ngg(-1) dw) was found at the most downstream sampling site near the head of the estuary, while average levels were highest at the tributary sampling site, ranging from 8.81-019.4 ngg(-1) dw. In general, the average concentrations in the tributary sampling sites were higher than those in the main stem sampling sites, which were 24.02 ± 10.15 and 19.97 ± 8.9 ngg(-1) dw, respectively. Among the 121 congeners, congener 1, 3, 22, 25, 33, 21, 53, 47, 41, 64, 71, 107, 136, 146, 158, 157, 200, 172, 189, 207, 205, 206, and 209 were all below the detection limit and were not found in any samples. Congeners 191, 85, and 26 were the most commonly detected, however, PCB 26, 12+13, and 52 were the most abundant congeners and contributed 11.5, 8.4, and 6.96% to the total PCBs, respectively. The results indicated that trace PCBs were still detectable in the sediment of the Donggang River and its tributaries. However, the concentrations were considerably lower than those found in other studies of nearby areas in Taiwan and around the world.