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The removal of eight typical endocrine disrupting compounds (EDCs) in a full scale membrane bioreactor combined with anaerobic-anoxic-oxic process (A2/O-MBR) for municipal wastewater reclamation located in Beijing was investigated. These EDCs, including 4-octylphenol (4-aPI, 4-nnonylphenol (4-n-NP), bisphenol A (BPA), estrone (El), 17α-estradiol (17a-E2), 17β-estradiol (17β-E2), estriol (E3) and 17a-ethinylestradiot (EE2), were simultaneously analyzed by gas chromatography/ mass spectrometry after derivatization. The concentrations of eight EDCs were also measured in sludge of anaerobic, anoxic, oxic and membrane tanks to measure sludge-water distribution coefficients (Kd values) as the indicator of adsorption propensity of target compound to sludge. The removal efficiencies of EDCs reached above 97%, except for 4-n-NP removal efficiency of 72%, 4-OP removal efficiency of 75% and EE2 removal efficiency of 87% in the A2/O-MBR process. The high Kd values indicated that the sludge had a large adsorption capacity for these EDC5, and significantly contributed to removal of EDCs. Yeast estrogen screen assay was performed on samples to assess the total estrogenic activity by measuring the 17ç3-E2 equivalent quantity (EEQ), expressed in ng-EEQ/L. The measured EEQ value was markedly reduced from 72.1 ng-EEQ/L in the influent to 4.9 ng-EEQ/L in the effluent. Anoxic tank and anaerobic tank contributed to 80% and 37% in total EEQ removal, respectively. [ABSTRACT FROM AUTHOR]

Occurrence and fate of eight kinds of selected endocrine-disrupting compounds (EDCs) in three sewage treatment plants (STPs) of Beijing, China was investigated. These EDCs, composed of 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), bisphenol A (BPA), estrone (E1), 17 α-estradiol (17 α-E2), 17 β-estradiol (E2), estriol (E3) and 17 α-ethinylestradiol (EE2), in every step of STPs, were simultaneously analysed by gas chromatography/mass spectrometry after derivatisation. All the EDCs were detected in the influents of three STPs, and BPA was the most abundant compound. The concentrations of EDCs ranged from 36.6 ng/l of 17 α-E2 (STP C) to 1342.3 ng/l of BPA (STP B) in the influent sewages and from below limits of detection of E2 and E3 (STP C) to 142.5 ng/l of E1 (STP B) in the effluent sewages. The STPs could not remove alkylphenols effectively from the aqueous phase with less than 40% reduction. BPA decreased over 90%, and steroid estrogens achieved considerable reductions from 64.8% of E2 to 94.9% of E3. Generally, biological treatment was more effective in removing alkylphenols, BPA and natural estrogens from the aqueous phase than primary treatment. However, the synthetic estrogen, EE2, was mostly removed by the primary treatment with about 63.5% reduction. It is the first time that the concentration of 17 α-E2 in the sewage of China was reported in this paper. The compound might have a bearing with the waste effluents of dairy farms around urban area of Beijing. [ABSTRACT FROM AUTHOR]

The occurrence of arsenic (As) in groundwater in fourteen villages in Houshayu Town, Shunyi District, Beijing, China, was investigated, and a column experiment for the removal of As was conducted on-site with a pellet type iron-cerium (Fe-Ce) bimetal oxide adsorbent prepared in lab. The As concentration in the groundwater of twelve villages exceeds the maximum contamination level (10 μg/L) of the World Health Organization, and two of them exceed that of China (50 μg/L). A column experiment at a space velocity of 3 h-1 shows that the Fe-Ce adsorbent could remove As(V) (total As, 71 ± 19.7 μg/L) from groundwater with high efficiency. Around 11,500 bed volumes were gained when As(V) in the effluent exceeds 10 μg/L, giving an accumulated adsorption capacity of 6.0 mg As(V)/g adsorbent. Both batch tests and the column test suggest that humic substances might compete with As(V) for the adsorption sites, which disappeared after the column was continuously operated for more than two weeks. The effluent quality including heavy metals, radioactivity, etc., was confirmed to meet the drinking water standards of WHO and China. [ABSTRACT FROM AUTHOR]