Removal of Estrogens in Municipal Wastewater Treatment under Aerobic and Anaerobic Conditions:  Consequences for Plant Optimization

Abstract

The removal of estrogens (estrone E1, estradiol E2, and ethinylestradiol EE2) was studied in various municipal wastewater treatment processes equipped for nutrient removal. A biological degradation model is formulated, and kinetic parameters are evaluated with batch experiments under various redox conditions. The resulting model calculations are then compared with sampling campaigns performed on differenttypes of full-scale plant: conventional activated-sludge treatment, a membrane bioreactor, and a fixed-bed reactor. The results show a > 90% removal of all estrogens in the activated sludge processes. (Due to the analytical quantification limit and low influent concentrations, however, this removal efficiency represents only an observable minimum.) The removal efficiencies of 77% and > or = 90% for E1 and E2, respectively, in the fixed-bed reactor represent a good performance in view of the short hydraulic retention time of 35 min. The first-order removal-rate constant in batch experiments observed for E2 varied from 150 to 950 d(-1) for a 1 gSS L(-1) sludge suspension. The removal efficiency of E1 and EE2 clearly depends on the redox conditions, the maximum removal rate occurring under aerobic conditions when E1 was reduced to E2. Sampling campaigns on full-scale plants indicate that the kinetic values identified in batch experiments (without substrate addition) for the natural estrogens may overestimate the actual removal rates. Although this paper does not give direct experimental evidence, it seems that the substrate present in the raw influent competitively inhibits the degradation of E1 and E2. These compounds are therefore removed mainly in activated sludge compartments with low substrate loading. Theoretical evaluation leads us to expect that diffusive mass transfer inside the floc (but not across the laminar boundary layer) appreciably influences the observed degradation rates of E1 and E2, but not of EE2.

Pharmaceuticals and personal care products in effluent matrices: A survey of transformation and removal during wastewater treatment and implications for wastewater management

“…3 compares PPCP concentrations measured in WWTP influents to concentrations measured in the corresponding effluents of MBRs utilized for wastewater treatment. 21,27,29,30,38,39,70,71 Also included are data previously presented in Fig. 1 for conventional wastewater treatment.…”

Trace organic contaminants in biosolids: Impact of conventional wastewater and sludge processing technologies and emerging alternatives

“…Anaerobic treatment is marked by unique biotransformation pathways, such as reductive dehalogenation of chlorinated compounds, conversion of natural hormones, and enantioselective biodegradation [4,62,63]. Reductive dehalogenation of six chlorophenols was observed in upflow anaerobic sludge blanket reactors, and the reaction involved either hydrogenolysis, i.e.…”

Removal of Estrogens by Activated Sludge Under Different Conditions Using Batch Experiments

“…Thus, Li et al (2008) considered that this estrogen is strongly adsorbed on the activated sludge particles, while other authors indicated that E2 is rapidly oxidized to E1 (Combalbert and Hernandez-Raquet, 2010;Desmiarti and Li, 2013;Joss et al, 2004).…”

“…Li et al (2008) observed that the presence of different glucose concentrations as an additional carbon source impaired E2 degradation. Joss et al (2004) compared the sludges from activated sludge and membrane bioreactor treatment systems and found that the sludge age and the size of the sludge flocs significantly influenced estrogen removal. Hashimoto and Murakami (2009) evaluated the presence of 17α-ethinylestradiol (EE2) in the liquid and solid phases of activated sludge tests and verified a 2 h lag phase and the complete removal and degradation of EE2 after 24 h. Furthermore, Chang et al (2006) considered the degradation of estrone (E1) and E2 in short-term (72 h) tests and found that both E1 and E2 were removed (approximately 100%) when using initial concentrations of 100 and 1000 µg L -1 .…”