Fate and seasonal variation of endocrine-disrupting chemicals in a sewage treatment plant with A/A/O process

Abstract

a b s t r a c tThe fate and seasonal variation of several typical endocrine-disrupting chemicals (EDCs), including estrone (E1), 17b-estradiol (E2), 17a-ethinylestradiol (EE2), estriol (E3), bisphenol A (BPA) and 4-nonylphenol (NP), were investigated in a municipal sewage treatment plant (STP) employing an anaerobic/ anoxic/oxic (A/A/O) process located in Beijing, China by monitoring their concentrations in both wastewater and activated sludge in four seasons throughout 2009. Results indicate that in summer, the examined STP could effectively remove 75.4% of E1 and more than 90% of all other studied EDCs from the wastewater. The biodegradation in the A/A/O process was the primary removal mechanism. Moreover, the removal of EDCs from the wastewater in the A/A/O bioreactor and their concentrations in the solid phase of return sludge exhibited an obvious seasonal fluctuation. The concentrations of EDCs in the effluent and return sludge were much higher in winter and spring than in summer and autumn, which was closely related to the microbial activity and the concentration of mixed liquor suspended solids (MLSS). Therefore, this study may raise a particular concern regarding the removal of EDCs from wastewater and the disposal of excess sludge in cold seasons.

Occurrence, removal, and fate of progestogens, androgens, estrogens, and phenols in six sewage treatment plants around Dianchi Lake in China

“…Stasinakis et al (2008) reported in influent that almost 45-50 % of phenolic EDCs were found in the particulate phase. During the process of aeration, phenolic EDCs originally adhering to the grits were peeled off due to the agitation of air (Nie et al 2012). But after dealing with vortex-type grit chamber and horizontal flow grit chamber, phenolic EDCs could be removed slightly.…”

“…It has been seriously concerned, in recent years, the negative effects of endocrine disrupting chemicals (EDCs) present in the aquatic environment on wildlife and human around the world (Harries et al 1997;Mills and Chichester 2005;Nie et al 2012;Tsutsumi 2005;Tyler et al 1998). …”

“…Zhang and Zhou (2008) reported that EDCs were not significantly removed by primary treatment process and secondary treatment process was mainly stage to removing EDCs. Most studies on secondary treatment technologies have focused on anaerobic/anoxic/ oxic (A/A/O) process Liu et al 2012b;Nie et al 2012). There is few data, however, for the systematic study about other treatment technologies, such as oxidation ditch (OD), anoxic-anaerobic-anoxic membrane bioreactor (3AMBR), and intermittent cyclic extended aeration system (ICEAS).…”

“…In the six investigated STPs around Dianchi Lake, the above four kinds of secondary treatment technologies are adopted, and the advanced treatment process was set, including two units of filter and ultraviolet disinfection. Usually, there are three pathways for the removal/transport of EDCs in the STPs: (1) biodegradation, (2) discharge into natural aquatic environment from final effluents, and (3) adsorbed to excess sludge (Nie et al 2012). In order to assess the contribution of these processes during treatment, the mass load of EDCs was calculated.…”

Transformation and fate of natural estrogens and their conjugates in wastewater treatment plants: Influence of operational parameters and removal pathways

“…Human and animal excretions constituted the main sources of NEs in the environment, while the occurrence of NEs in municipal wastewater is primarily attributed to human excretions. The occurrence and behavior of NEs in wastewater treatment plants (WWTPs) has been extensively investigated around the world (Hamid and Eskicioglu, 2012;Liu et al, 2009;Nie et al, 2012), but the reported NE removal efficiencies in different WWTPs are largely variable. An important reason for the inconsistencies is that the operational parameters, including temperature, hydraulic retention time (HRT) and sludge retention time (SRT), varied greatly among the different studies.…”