ReviewRemoval mechanisms for endocrine disrupting compounds (EDCs) in wastewater treatment — physical means, biodegradation, and chemical advanced oxidation: A review
Introduction
Endocrine disrupting compounds (EDCs) are chemicals with the potential to elicit negative effects on the endocrine systems of humans and wildlife. In the past few decades, research efforts to combat this problem have grown immensely. Key to the solution for this problem is the identification of EDCs, the accurate measurement of their presence in aquatic systems, and development of methods for their elimination from the environment.
Various natural and synthetic chemical compounds have been identified that induce estrogen-like responses; including pharmaceuticals, pesticides, industrial chemicals, and heavy metals (Giesy et al., 2002). The US Environmental Protection Agency (USEPA) defines an EDC as: “An exogenous agent that interferes with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and/or behavior.” (USEPA, 1997)
This broad class of chemicals includes natural estrogens, such as estrone (E1),17β-estradiol (E2), and estriol (E3) (Blair et al., 2000, Nishihara et al., 2000, Folmar et al., 2002, Zhu et al., 2006); natural androgens such as testosterone (T), dihydrotestosterone (DHT), and androsterone (A) (Bauer et al., 2000, Fang et al., 2003); artificial synthetic estrogens or androgens, such as ethynylestradiol (EE2), Norgestrel (N), and Trenbolone (Tr) (Blair et al., 2000, Bauer et al., 2000); phytoestrogens including isoflavonoides and coumestrol (Bacaloni et al., 2005, Stopper et al., 2005) as well as other industrial compounds such as bisphenol A, nonylphenol (Mocarelli et al., 1996, Ramamoorthy et al., 1997, Howdeshell et al., 1999, Ying et al., 2002). Such chemicals as those above have been found existing in wastewater, surface waters, sediments, groundwater, and even drinking water (Ternes et al., 1999a, Befenati et al., 2003, Petrovic et al., 2003, Snyder et al., 2003, Vethaak et al., 2005, Durhan et al., 2006, Fernandez et al., 2007). Wastewater treatment plants have been studied as a major source for EDCs (Kolpin et al., 2002, Legler et al., 2002, Snyder et al., 2003, Nakada et al., 2006, Tan et al., 2007). Being EDCs exist in extremely low concentration ( μg/L or ng/L), highly sensitive measurement of EDCs is necessary, including chemical monitoring, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS), gas chromatography-tandem mass spectrometry (GC-MS/MS), high performance liquid chromatography (HPLC) and bioassay (both in vitro and in vivo). Detailed information may be found in Flemming and Bent (2003) and Karin (2003).
EDCs have been attributed as a cause of reproductive disturbance in humans and wildlife (Hayes et al., 2002, Oak et al., 2004, Samir et al., 2006, Campbell et al., 2006). Human exposure to these chemicals in the environment is a critical concern with unknown long-term impacts. Natural and synthetic EDCs are released into the environment by humans, animals and industry; mainly through sewage treatment systems before reaching the receiving bodies (soil, surface water, sediment and ground water), EDCs' main distribution in the environment is illustrated in Fig. 1. (Flemming and Bent, 2003). EDCs are a latent crisis to humans and the environment. Theoretically this crisis could be easily controlled, if EDCs can be completely removed from sewage at sewage treatment plants before final release into the environment. EDCs removal methods fall into three categories; physical removal, biodegradation and chemical advanced oxidation (CAO). This article will focus on the latest progress of these removal methods.
Section snippets
Absorption by activated carbon
Use of activated carbon (AC) is a well-known process for removing various organic contaminants. AC is most commonly applied as a powdered feed (powder activated carbon, PAC) or in a granular form (granular activated carbon, GAC) in packed bed filters. Several authors have demonstrated the efficiency of AC, both as PAC and GAC, for the removal of trace organic pollutants from water (Matsui et al., 2002a, Matsui et al., 2002b, Asada et al., 2004, Westerhoff et al., 2005, Zhou et al., 2007). In
Removal of EDCs by existing wastewater treatment systems
The objective of wastewater treatment systems is to remove organic substances, phosphorus and nitrogen from wastewater, but research has discovered that EDCs can also be reduced by wastewater treatment systems. Among wastewater treatment systems, the activated sludge process is the most widely used in the world, and as the proportion of removal by primary settling, chemical precipitation, aerating volatilization and sludge absorption was small, the majority of EDCs in wastewater is regarded as
EDCs removal by chemical advanced oxidation
Within the past few years, there have been numerous studies on the removal of EDCs through the use of different chemical oxidants, known as chemical advanced oxidation (CAO). The essential mechanisms of CAO are mineralization of pollutants in wastewater to CO2 or transference of pollutants to some other metabolite products by some strong oxidizers through oxidation–reduction reactions. Therefore the key point for CAO is the choice of oxidizer. Redox potentials of some wastewater treatment
Conclusions
Pollutant removal from wastewater is a process with high energy consumption, where cost and efficiency are the key considerations for their application. Biodegradation processes have proven to be the most cost-effective processes. Among these, the activated sludge process is widely applied all over the world. Although some investigations suggested that high EDC removal rates could be achieved through conventional biological wastewater treatment processes, further data showed that the removal
Acknowledgements
This work has been partly supported by the Institute of Osaka International House Foundation, Osaka, Japan. The authors would like to thank the Institute of Osaka International House Foundation, Osaka, Japan, for the scholarship support to overseas students. The authors would also like to thank CRAIG Farnham, Graduate School of Engineering, Osaka City University, who helped to correct the English of the manuscript.
References (162)
- et al.
Change in membrane performance due to organic fouling in nanofiltration (NF)/reverse osmosis (RO) applications
Sep Purif Technol
(2007) - et al.
Retention of a wide variety of organic pollutants by different nanofiltration/reverse osmosis membranes controlling parameters of process
J Membr Sci
(2003) - et al.
Determination of isoflavones and coumestrol in river water and domestic wastewater sewage treatment plants
Anal Chim Acta
(2005) - et al.
Kinetic and mechanistic investigations of progesterone reaction with ozone
Water Res
(2006) - et al.
Liquid chromatography-tandem mass spectrometry analysis of estrogenic compounds in coastal surface water of the Baltic Sea
J Chromatogr A
(2005) - et al.
Analysis and occurrence of estrogenic hormones and their glucuronides in surface water and waste water in The Netherlands
Sci Total Environ
(1999) - et al.
Rapid yeast estrogen bioassays stably expressing human estrogen receptor α and β, and green fluorescent protein: a comparison of different compounds with both receptor types
J Steroid Biochem Mol Biol
(2004) - et al.
Biologically directed environmental monitoring, fate, and transport of estrogenic endocrine disrupting compounds in water: a review
Chemosphere
(2006) - et al.
Assessment of river contamination by estrogenic compounds in Paris area (France)
Sci Total Environ
(2004) - et al.
Adsorption of trace steroid estrogens to hydrophobic hollow fibre membranes
Desalination
(2002)
Anaerobic degradation of nonylphenol in sludge
Chemosphere
Trace analysis of androgens and progestogens in environmental waters by ultra-performance liquid chromatography–electrospray tandem mass spectrometry
J Chromatogr A
Biological assessment of bisphenol A degradation in water following direct photolysis and UV advanced oxidation
Chemosphere
Biological assessments of a mixture of endocrine disruptors at environmentally relevant concentrations in water following UV/H2O2 oxidation
Sci Total Environ
Effects of activated carbon types and service life on removal of endocrine disrupting chemicals: amitrol, nonyphenol and bisphenol A
Chemosphere
The solids retention time—a suitable design parameter to evaluate the capacity of wastewater treatment plants to remove micropollutants
Water Res
Anaerobic biotransformation of estrogens
Sci Total Environ
Fate of natural estrogen conjugates in municipal sewage transport and treatment facilities
Sci Total Environ
Degradation of bisphenol A in natural water
Chemosphere
Degradation and behavior of natural steroid hormones in cow manure waste during biological treatments and ozone oxidation
J Biosci Bioeng
An assessment of estrogenic organic contaminant in Canadian wastewaters
Sci Total Environ
Quantitation of estrogens in ground water and swine lagoon samples using solid-phase extraction, pentafluorobenzyl/trimethylsilyl derivatizations and gas chromatography–negative ion chemical ionization tandem mass spectrometry
J Chromatgr A
A comparison of the estrogenic potencies of estradiol, ethynylestradiol, diethylstilbestrol, nonyphenol and methoxychlor in vivo and in vitro
Aquat Toxicol
Adsorbability of estrone and 17-βestradiol in water onto activated carbon
Water Res
Cell bioassays for detections of aryl hydrocarbon (AhR) and estrogen receptor (ER) mediated activity in environmental samples
Mar Pollut Bull
Rejection of endocrine disrupting compounds (bisphenol A, bisphenol F and triethyleneglycol dimethacrylate) by membrane technologies
Desalination
Determination of selected human pharmaceutical compounds in effluent and surface water samples by high-performance liquid chromatography-electrospray tandem mass spectrometry
J Chromatogr A
Monitoring of selected estrogenic hormones and industrial chemicals in groundwaters and surface waters in Austria
Sci Total Environ
Degradation of 17β-estradiol and bisphenol A in aqueous medium by using ozone and ozone/UV techniques
J Hazard Mater
Determination of estrogens and their conjugates in water using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry
J Chromatogr A
Adsorption of alkylphenols onto microporous carbons prepared from coconut shell
Synth Met
Progress in the development and use of ferrate (VI) salt as an oxidant and coagulant for water and wastewater treatment
Water Res
Occurrence and treatment trials of endocrine disrupting chemicals (EDCs) in wastewaters
Chemosphere
What difference might sewage treatment performance make to endocrine disruption in rivers
Environ Pollut
Rejection properties of NF membranes for alkylphenols
Desalination
Degradation of bisphenol A in water by the photo-Fenton reaction
J Photochem Photobiol A
Rejection of organic micropollutants (disinfection by products, endocrine disrupting compounds, and pharmaceutically active compounds) by NF/RO membranes
J Membr Sci
Rejection of neutral endocrine disrupting compounds (EDCs) and pharmaceutical active compounds (PhACs) by RO membranes
J Membr Sci
Occurrence and biological effect of exogenous steroids in the Elkhorn river, Nebraska, USA
Sci Total Environ
Input/output balance of estrogenic active compounds in a major municipal sewage plant in Germany
Chemosphere
Analytical methodologies for determining the occurrence of endocrine disrupting chemicals in sewage treatment plants and natural waters
Anal Chim Acta
Bioassay-derived androgenic and estrogenic activity in municipal sewage in Australia and New Zealand
Ecotoxicol Envion Saf
Change in sex ratio with exposure to dioxin
Lancet
Pharmaceutical chemicals and endocrine disrupters in municipal wastewater in Tokyo and their removal during activated sludge treatment
Water Res
Adsorption characteristics of bisphenol A onto carbonaceous materials produced from wood chips as organic waste
J Colloid Interface Sci
The use of in vitro bioassays to quantify endocrine disrupting chemicals in municipal wastewater treatment plant effluents
Sci Total Environ
Estrogenic hormone removal from wastewater using NF/RO membranes
J Membr Sci
Adsorption properties of endocrine disruptors onto activated carbon
J Water Waste
Oxidation of bisphenol A, 17β-estradiol, and 17α-ethynylestradiol and byproduct estrogenicity
Environ Toxicol
Fate of estrogens in a municipal sewage treatment plant
Environ Sci Technol
Cited by (630)
CoFe<inf>2</inf>O<inf>4</inf>-titanium hollow fiber membrane filtration coupling peroxymonosulfate activation for water purification: Preparation, performance and mechanism
2024, Separation and Purification TechnologyThe impact of reduced sulfur compounds on aerobic granular sludge formation and biological phosphorus removal
2024, Biochemical Engineering JournalSimultaneous generation of free radicals, Fe(IV) and Fe(V) by ferrate activation: A review
2024, Chemical Engineering Journal