Removal of typical endocrine disrupting chemicals by membrane bioreactor: in comparison with sequencing batch reactor

2011 ◽  
Vol 64 (10) ◽  
pp. 2096-2102 ◽  
Author(s):  
Yingjun Zhou ◽  
Xia Huang ◽  
Haidong Zhou ◽  
Jianhua Chen ◽  
Wenchao Xue

The removal of endocrine disrupting chemicals (EDCs) by a laboratory-scale membrane bioreactor (MBR) fed with synthetic sewage was evaluated and moreover, compared with that by a sequencing batch reactor (SBR) operated under same conditions in parallel. Eight kinds of typical EDCs, including 17β-estradiol (E2), estrone (E1), estriol (E3), 17α-ethynilestradiol (EE2), 4-octylphenol (4-OP), 4-nonylphenol (4-NP), bisphenol A (BPA) and nonylphenol ethoxylates (NPnEO), were spiked into the feed. Their concentrations in influent, effluent and supernatant were determined by gas chromatography-mass spectrometry method. The overall estrogenecity was evaluated as 17β-estradiol equivalent quantity (EEQ), determined via yeast estrogen screen (YES) assay. E2, E3, BPA and 4-OP were well removed by both MBR and SBR, with removal rates more than 95% and no significant differences between the two reactors. However, with regard to the other four EDCs, of which the removal rates were lower, MBR performed better. Comparison between supernatant and effluent of the two reactors indicated that membrane separation of sludge and effluent, compared with sedimentation, can relatively improve elimination of target EDCs and total estrogenecity. By applying different solids retention times (SRTs) (5, 10, 20 and 40 d) to the MBR, 10 and 5 d were found to be the lower critical SRTs for efficient target EDCs and EEQ removal, respectively.

2013 ◽  
Vol 765-767 ◽  
pp. 2944-2948 ◽  
Author(s):  
Xiao Ling Shao ◽  
Wen Qi Zhong ◽  
Xiao Yan Ma ◽  
Ang Gao ◽  
Xiang Yang Wu ◽  
...  

Yeast two-hybrid system was used to investigate the estrogenic activities of 13 kinds of representative endocrine disrupting chemicals (EDCs) and their combinary effects. Results show that the order of estrogenic potencies for these chemicals is: 17α-ethynylestradiol>diethylstilbestrol >17β-estradiol>estrone>estriol>branchedp-nonylphenol>4-t-octylphenol>bisphenol A>diethyl phthalate>4-n-nonylphenol>di-(2-ethylhexyl) phthalate>dibutyl phthalate>dimethyl phthalate. The mixture effects of multiple EDCs were compared to those obtained from individual chemicals, using the model of concentration addition. Results reveal that the estrogenicities of multicomponent mixtures of more than three (including three) of EDCs follow antagonistic effects, while there is no definite conclusion for binary systems. The less than additive effects were also confirmed in the spiked experiments conducted in the extracts of real water samples.


2012 ◽  
Vol 2 (2) ◽  
pp. 67-73 ◽  
Author(s):  
T. Trinh ◽  
B. van den Akker ◽  
H. M. Coleman ◽  
R. M. Stuetz ◽  
P. Le-Clech ◽  
...  

Submerged membrane bioreactors (MBRs) have attracted a significant amount of interest for decentralised treatment systems due to their small footprint and ability to produce high quality effluent, which is favourable for water reuse applications. This study provides a comprehensive overview of the capacity of a full-scale decentralised MBR to eliminate 17 endocrine disrupting chemicals (EDCs) and five indigenous microbial indicators. The results show that the MBR consistently achieved high removal of EDCs (>86.5%). Only 2 of the 17 EDCs were detected in the MBR permeate, namely two-phenylphenol and 4-tert-octylphenol. Measured log10 reduction values of vegetative bacterial indicators were in the range of 5–5.3 log10 units, and for clostridia, they were marginally lower at 4.6 log10 units. Removal of bacteriophage was in excess of 4.9 log10 units. This research shows that MBRs are a promising technology for decentralised water reuse applications.


Author(s):  
Chao Zhang ◽  
Tiziana Schilirò ◽  
Marta Gea ◽  
Silvia Bianchi ◽  
Angelo Spinello ◽  
...  

The intensive use of pesticides has led to their increasing presence in water, soil, and agricultural products. Mounting evidence indicates that some pesticides may be endocrine disrupting chemicals (EDCs), being therefore harmful for the human health and the environment. In this study, three pesticides, glyphosate, thiacloprid, and imidacloprid, were tested for their ability to interfere with estrogen biosynthesis and/or signaling, to evaluate their potential action as EDCs. Among the tested compounds, only glyphosate inhibited aromatase activity (up to 30%) via a non-competitive inhibition or a mixed inhibition mechanism depending on the concentration applied. Then, the ability of the three pesticides to induce an estrogenic activity was tested in MELN cells. When compared to 17β-estradiol, thiacloprid and imidacloprid induced an estrogenic activity at the highest concentrations tested with a relative potency of 5.4 × 10−10 and 3.7 × 10−9, respectively. Molecular dynamics and docking simulations predicted the potential binding sites and the binding mode of the three pesticides on the structure of the two key targets, providing a rational for their mechanism as EDCs. The results demonstrate that the three pesticides are potential EDCs as glyphosate acts as an aromatase inhibitor, whereas imidacloprid and thiacloprid can interfere with estrogen induced signaling.


2012 ◽  
Vol 2 (1) ◽  
pp. 22-32 ◽  
Author(s):  
Farrukh Basheer ◽  
I. H. Farooqi

The present study was aimed at the development of aerobic granules in sequencing batch reactor (SBR) for the biodegradation of p-nitrophenol (PNP). The reactor was started with 50 mg L−1 of PNP. Aerobic granules first appeared within 1 month of the start up of the reactor. The granules were large and strong and had a compact structure. The diameter of stable granules on day 200 was in the range of 2–3 mm. The integrity coefficient and granule density was found to be 98% and 1,031 kg m−3 respectively. The settling velocity of granules was found to be in the range of 3 × 10−2 to 4 × 10−2m s−1. The aerobic granules were able to degrade PNP up to 700 mg L−1 at a removal efficiency of 87%. Gas chromatography–mass spectrometry studies confirmed that the biodegradation of PNP occurred by an initial oxygenase attack that resulted in the release of nitrite and the accumulation of hydroquinone. The specific PNP degradation rate in aerobic granules followed the Haldane model for substrate inhibition. A high specific PNP degradation rate up to 0.872 g PNP g−1 VSS−1 d−1 was sustained up to PNP concentration of 200 mg L−1. Higher removal efficiency, good settling characteristics of aerobic granules, makes a SBR suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.


2010 ◽  
Vol 62 (11) ◽  
pp. 2501-2509 ◽  
Author(s):  
L. Y. Wang ◽  
X. H. Zhang ◽  
N. F. Y. Tam

Seven typical endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), 4-tert-octylphenol (OP), estrone (E1), estradiol (E2), 17α-estradiol (17α-E2), estriol (E3) and 17α-ethinylestradiol (EE2) in wastewater, were simultaneously determined with gas chromatography–mass spectrometry (GC–MS). Samples, including influents, effluents and wastewater of different unit processes, were taken seasonally from three different sewage treatment plants. The result showed that BPA and EE2 were the two main types of EDCs in all the samples. The average concentration of BPA were in the range of 268.1–2,588.5 ng l−1 in influents and 34.0–3,099.6 ng l−1 in effluents, while EE2 ranging from 133.1 to 403.2 ng l−1 and from 35.3 to 269.1 ng l−1, respectively. Seasonal change of EDCs levels in effluents was obvious between wet season and dry season. Besides, BPA and E3 could be effectively removed by the biological treatment processes (oxidation ditch and A2/O) with the unit removal of 64–91% and 63–100% for each compound, while other five EDCs had moderate or low removal rates. The study also proved that physical treatment processes, including screening, primary sedimentation and pure aeration, had no or little effect on EDCs removal.


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