Decrease of antiandrogenic activity in gray water and domestic wastewater treated by the MBR process

Abstract

In order to figure out the variation of the androgens/antiandrogens in wastewater treatment, androgenic/antiandrogenic activities were investigated in two membrane bioreactors (MBR) treating gray water and domestic wastewater, respectively, in Beijing city, China. The androgens and antiandrogens were extracted from water and solid samples by a solid phase extraction (SPE) method and the androgenic/antiandrogenic activities were detected with a recombined androgen receptor (AR) yeast assay. The results showed that there were no androgenic induction activities either in water or in solid samples, but all samples exhibited obvious antiandrogenic activities. The antiandrogenic activities in the suspended solids contributed to 27.4% of the total antiandrogenic activities in gray water and 37.7% in domestic wastewater. Although the concentration of flutamide equivalent (FEQ) of the domestic wastewater (3.1 mg L(-1)) was about three times higher than that of the gray water (1.1 mg L-(1)) in the liquid phase, the effluent FEQ of the two processes was comparable, and the concentrations were 53.7 ± 2.4 μg L(-1) and 68.9 ± 6.0 μg L(-1), respectively. By mass balance analysis, a total of 1825.2 mg FEQ antiandrogens flowed into the gray water and 4914.1 mg flowed into the domestic wastewater treatment process every day. More than 95% of the influent antiandrogens in the liquid phase was removed in both systems. And only 64.5 mg and 69.0 mg FEQ antiandrogens flowed out of gray water and domestic wastewater treatment processes every day. Biodegradation was considered to be the crucial antiandrogen removal mechanism in MBR, which contributed to 98% of the antiandrogen removal in the gray water treatment plant, and 91% in the domestic wastewater treatment plant.

Biological removal of antiandrogenic activity in gray wastewater and coking wastewater by membrane reactor process

“…Pretreatment was conducted according to the previous study with proper modification (Ma et al, 2013). In order to suppress possible biotic activity, an appropriate amount of methanol (2 mL/L) was added to each sample right after the sampling.…”

“…Some antiandrogens, e.g., triclosan, 4-nonylphenol, bisphenol A, octocrylene, butylparaben, propylparaben, benzophenone-3, and 3,4-dichlorophenol, were found in gray wastewater (Leal et al, 2010). We had previously reported the occurrence and removal of antiandrogenic activity of gray wastewater in a MBR treatment system (Ma et al, 2013). Nevertheless, further research is still needed on the specific properties of antiandrogens in gray wastewater and their removal in the treatment system.…”

Effects of short-term exposure to the model anti-androgen, flutamide on reproductive function based endpoints in female Murray rainbowfish (Melanotaenia fluviatilis)

“…Antiandrogenic activity of 935 mg flutamide equivalent concentration (FEQ)/L has been detected in the surface water in China (Zhao et al, 2011). A recent study reported that more than 1800 mg FEQ/ L anti-androgens flow into the graywater every day in Beijing (China) (Ma et al, 2013). In vitro anti-androgenic activity (370-4223 mg FEQ/L) has also been determined in the freshwater in Italy (Urbatzka et al, 2007).…”

“…The anti-androgenic nature of phthalates is also uncertain in fish because they have been reported to displace 17β-estradiol (E2) from the ERs in rainbow trout (Oncorhynchus mykiss) (Matthews et al, 2000), thereby, suggesting an in vivo estrogenic MoA. The detection of anti-androgenic activity in water worldwide (Jobling et al, 2009;Jolly et al, 2009;Ma et al, 2013;Urbatzka et al, 2007) and foreseeing the importance of androgens in the process of oocyte maturation in fish such as yellow croaker (Larimichthys crocea), European sea bass (Dicentrarchus labrax), Japanese eel (Anguilla japonica) and Atlantic cod (Gadus morhua) (Endo et al, 2011;Garcia-Lopez et al, 2011;Kortner et al, 2009;Pu et al, 2013), have necessitated the evaluation and characterisation of the effects of a reference anti-androgen on the reproductive function based end-points in female fish.…”

“…We proposed to test if a short-term exposure to biologically active concentrations of flutamide would affect the reproductive function based on end-points such as circulating levels of VTG and sex steroid hormones -E2 and 11-keto testosterone (11-KT); and brain aromatase activity in female rainbowfish. Based on the concentrations of flutamide used in overseas in vivo fish studies (Kang et al, 2006;Martinovic-Weigelt et al, 2011) and the values of the anti-androgenic activity detected in freshwater by in vitro screens (Ma et al, 2013;Urbatzka et al, 2007;Zhao et al, 2011), we used the concentrations of 125-1000 mg/L. These concentrations were not lethal to cause mortality but were biologically active to cause reproductive changes.…”