title: Sludge Retention Time as a Suitable Operational Parameter to Remove Both Estrogen and Nutrients in an Anaerobic-Anoxic-Aerobic Activated Sludge System.
abstract: Estrogen in wastewater are responsible for a significant part of the endocrine-disrupting effects observed in the aquatic environment. The effect of sludge retention time (SRT) on the removal and fate of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in an anaerobic-anoxic-oxic activated sludge system designed for nutrient removal was investigated by laboratory-scale experiments using synthetic wastewater. With a hydraulic retention time of 8 h, when SRT ranged 10-25 days, E2 was almost completely removed from water, and EE2 removal efficiency was 65%-81%. Both estrogens were easily sorbed onto activated sludge. Distribution coefficients (Kd) of estrogens on anaerobic sludge were greater than those on anoxic and aerobic sludges. Mass balance calculation indicated that 99% of influent E2 was degraded by the activated sludge process, and 1% remained in excess sludge; of influent EE2, 62.0%-80.1% was biodegraded; 18.9%-34.7% was released in effluent; and 0.88%-3.31% remained in excess sludge. Optimal SRT was 20 days for both estrogen and nutrient removal. E2 was almost completely degraded, and EE2 was only partly degraded in the activated sludge process. Residual estrogen on excess sludge must be considered in the sludge treatment and disposal processes. The originality of the work is that removal of nutrients and estrogens were linked, and optimal SRT for both estrogen and nutrient removal in an enhanced biological phosphorus removal system was determined. This has an important implication for the design and operation of full-scale wastewater treatment plants.
authors: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University , Shanghai, China . ; College of Civil Engineering, Huaqiao University , Xiamen, Fujian, China .
authors: Qingling
authors: Q
authors: Zeng
authors: Yongmei
authors: Y
authors: Li
authors: Shijia
authors: S
authors: Yang
keywords: activated sludge; biodegradation; estrogen; removal; sorption; wastewater
references: J Hazard Mater. 2012 Jan 15;199-200:88-95
references: 22119197
references: Environ Sci Pollut Res Int. 2010 Mar;17(3):529-38
references: 19495820
references: Environ Sci Technol. 2008 Aug 15;42(16):6141-7
references: 18767678
references: Water Sci Technol. 2010;61(7):1663-71
references: 20371923
references: Environ Sci Technol. 2004 Jun 1;38(11):3047-55
references: 15224734
references: Aquat Toxicol. 2011 Jan 17;101(1):38-48
references: 20888052
references: Sci Total Environ. 2010 Sep 1;408(19):4257-69
references: 20633734
references: Sci Total Environ. 2006 Aug 31;367(2-3):932-41
references: 16616321
references: Water Res. 2003 Sep;37(15):3785-91
references: 12867347
references: Sci Total Environ. 1999 Jan 12;225(1-2):81-90
references: 10028705
references: Chemosphere. 2005 Sep;61(1):139-46
references: 16157176
references: Water Res. 2008 Jun;42(12):3146-52
references: 18405936
references: Water Res. 2005 Jan;39(1):97-106
references: 15607169
references: Water Res. 2007 May;41(10):2117-26
references: 17416401
references: Appl Microbiol Biotechnol. 2005 Apr;67(1):106-12
references: 15290133
references: Environ Sci Technol. 2007 Feb 1;41(3):884-90
references: 17328198
references: Water Res. 2009 Feb;43(3):573-82
references: 19019407
references: Environ Sci Technol. 2009 Sep 1;43(17):6646-54
references: 19764230
references: Environ Toxicol Chem. 2011 Feb;30(2):413-26
references: 21038429
references: Environ Monit Assess. 2011 Apr;175(1-4):431-41
references: 20556648
references: Sci Total Environ. 2009 Jan 1;407(2):731-48
references: 18992918
references: Environ Toxicol Chem. 2008 Aug;27(8):1649-58
references: 18315391
references: Environ Sci Technol. 2006 Dec 15;40(24):7896-902
references: 17256545
references: Arch Environ Contam Toxicol. 2010 Apr;58(3):576-86
references: 20130850
references: Water Sci Technol. 2004;50(5):149-56
references: 15497842
references: Chemosphere. 2010 Sep;81(1):1-6
references: 20719356