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We developed an original analytical method for monitoring five estrogens, nine androgens, nine progestogens, six glucocorticoids, and one mineralocorticoid in one water sample using liquid chromatography-electrospray tandem mass spectrometry, and then 45 river, 13 discharging sites, and 4 composite effluent samples were analyzed to reveal their occurrence and sources in urban rivers. Of the 45 river samples, androgens were the dominant steroids detected (total concentrations up to 480 ng/L), followed by glucocorticoids (up to 52 ng/L), progestogens (up to 50 ng/L, and estrogens (up to 9.8 ng/L). The summed concentration for each class of detected hormones in 13 discharging site samples was higher than that in river samples, up to 1887 ng/L for androgens, 390 ng/L for glucocorticoids, 75 ng/L for progestogens, and 25 ng/L for estrogens. A principal component analyses with multiple linear regression based on the profiles of all target compounds was applied to identify the source apportionment and to predict the contribution from different sources. It was found that 62.7% of the mean summed hormones were contributed by freshly discharged untreated sewage, 29.4% by treated sewage and/or naturally attenuated untreated sewage, and 7.9% by an unknown source, possibly pharmaceutical manufacturing plants.

This paper first reports the occurrence of sixglucocorticoids (prednisone, prednisolone, cortisone, cortisol, dexamethasone, and 6alpha-methylprednisolone) in sewage treatment plants (STPs) and receiving rivers by establishing a method for analyzing glucocorticoids in complex environmental waters. For the various types of aqueous matrices considered, the absolute recoveries were from 73 to 99%, and limits of quantification were below 0.2 ng/L. Among the seven STPs studied, the average concentrations of prednisone, prednisolone, cortisone, cortisol, dexamethasone, and 6alpha-methylprednisolone in influents were, respectively, 2.6 +/- 2.1, 3.0 +/- 1.6, 30 +/- 21, 39 +/- 26, 1.2 +/- 0.70, and 0.62 +/- 0.65 ng/L, and their percent removals were 99 +/- 3.1, 78 +/- 8.8, 99 +/- 1.2, 98 +/- 2.5, 99 +/- 1.8, and 100 +/- 0%, respectively. The lower removal of prednisolone was found to be due to its relatively low efficiency of biodegradation, especially in anoxic and aerobic units. The frequently detected glucocorticoids in effluents were prednisolone, cortisol, and cortisone with average concentrations 0.56 +/- 0.06, 0.50 +/- 0.33, and 0.26 +/- 0.10 ng/ L. In the receiving waters, the Tonghui and Qing Rivers, the concentrations of these compounds in some samples were much higher than those in their corresponding STP effluents; these differences depended on the sampling date, suggesting that there was random discharging of untreated wastewaters into these rivers. In addition, the ratio between the combined concentrations of two natural glucocorticoids (cortisol and cortisone) and the concentration of one synthetic glucocorticoid, prednisolone, was found to be a potential index to reflect the wastewater discharging.

a b s t r a c tTo investigate the fate of penicillin G (PEN G) in the wastewater from a PEN G production facility and the receiving river, an analytical method was developed for the simultaneous detection of PEN G and five degradation products using liquid chromatography-electros- were found to be penilloic acid, penicilloic acid and isopenillic acid, which occupied 65.8%, 20.4% and 12.9%, respectively, of the total concentration at the last site. This is the first study on the behaviors of PEN G and its main degradation products in wastewater treatment processes and the aquatic environment.

Scientists have become increasingly concerned about the occurrence of antibacterial resistance in the environment. In this study, Escherichia coli resistant to one or more antibiotics among nine antibiotics was screened from Wenyu River Basin in Beijing, China, with mean frequency of 48.7 +/- 8.7% of 388 isolates in summer and 47 +/- 6% of 236 isolates in winter. The mean multiantibiotic resistance (MAR) index in summer was 0.11 +/- 0.03, slightly lower than that (0.14 +/- 0.04) in winter. Most frequent resistance appeared for sulfonamides, tetracycline, and ampicillin. The distribution of 20 tetracycline, three sulfonamide, and three beta-lactam resistance genes was assessed in the resistant isolates. While 97% of the ampicillin (AMP) resistant mechanism could be explained by the resistance gene TEM, 90% of the tetracycline (TC) and 96% of the sulfonamide (SXT) resistances could be explained by tet(A), tet(B), tet(M), and their combinations and sul(I), sul(II), sul(III), and their combinations, respectively. tet(M), a tetracycline-resistant gene originally detected in Gram-positive bacteria, and its combinations with tet(A) or tet(B) were first detected in E. coli isolated from a natural river basin, suggesting that tet(M) in E. coli might have been transferred from other bacterial species through horizontal gene transfer, which was supported by the fact that no tet(M) was detected in the isolates of human and chicken sources, except for only one isolate from swine. The source of sulfonamide-resistant E. coli in the river was supposed to be mainly from humans, based on a comparison of the sulfonamide resistance genotypes in animals and humans.

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This work investigated the behaviors of seven glucocorticoids, eight androgens, and nine progestogens compared to six estrogens in a municipal sewage treatment plant (STP) in Beijing, China. Among all of the hormones considered, androgens were the dominant steroids detected in all samples (total concentrations up to 10 216±912 ng/L for influents, 171±10 ng/L for effluents, and 647±52 ng/g for dehydrated sludge samples), followed by estrogens (102±8 ng/L, 14±2 ng/L, and 14±1 ng/g), progestogens (57±6 ng/L, 8±2 ng/L, and 13±3 ng/g), and glucocorticoids (42±2 ng/L, 0.7±0.1 ng/L, and 1.2±0.3 ng/g). With the exception of 19-nor-4-androstene-3,17-diol (NAD, 67%), removal rates for androgens were relatively high (98-99%), while those for glucocorticoids, estrogens, and all progestogens except 6α-methylhydroxyprogesterone (MHPT) were 85-99%, 78-99%, and 73-96%, respectively. Glucocorticoids, androgens, and progestogens were mainly removed by degradation as with estrogens, while different behaviors were observed in the aerated grit chamber, anaerobic tank, anoxic tank, and aerobic tank units. Many of the detected glucocorticoids, androgens, and progestogens were eliminated in the anaerobic tank, but estrogens were largely degraded in the aerobic one. Significant increases in the mass of 21α-hydroxyprogesterone (21-HPT) and MHPT in the anaerobic tank and anoxic tank, respectively, were due to deconjugation.