The removal of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs during wastewater treatment and its impact on the quality of receiving waters
Introduction
Pharmaceuticals, personal care products, endocrine disruptors and illicit drugs (PPCPs) are regarded as emerging environmental contaminants as many PPCPs are ubiquitous, persistent and biologically active compounds with recognised endocrine disruption functions (Daughton and Ternes, 1999, Fent et al., 2006). Pharmaceuticals such as antibiotics or analgesics have frequently been found in surface waters at concentrations reaching μg L−1 (Ashton et al., 2004, Bendz et al., 2005, Calamari et al., 2003, Glassmeyer et al., 2005, Gross et al., 2006, Kolpin et al., 2002, Kolpin et al., 2004, Moldovan, 2006, Roberts and Thomas, 2006, Vanderford et al., 2003, Vieno et al., 2005, Vieno et al., 2006). In contrast personal care products and illicit drugs have hardly been studied in environmental matrices and limited evidence of their presence in the environment exists to date (Boleda et al., 2007, Hummel et al., 2006; Zuccato et al., 2008).
There are several direct and indirect pathways through which PPCPs can be introduced into the aqueous environment. Insufficiently treated municipal wastewater discharge is identified as the major route responsible for surface water contamination with PPCPs (Bendz et al., 2005, Bernhard et al., 2006, Carballa et al., 2004, Castiglioni et al., 2006a, Göbel et al., 2007, Gómez et al., 2007, Jones et al., 2007, Joss et al., 2005, Lindqvist et al., 2005, Lishman et al., 2006, Nakada et al., 2006, Palmer et al., 2008, Santos et al., 2007, Spongberg and Witter, 2008, Tauxe-Wuersch et al., 2005, Terzić et al., 2008, Vieno et al., 2006, Yu et al., 2006). The likelihood of water contamination with PPCPs as a result of discharge of WWTP effluent depends on several factors. Among the most important are: physico-chemical properties of pollutants, the type of wastewater treatment technology implemented and climatic conditions (e.g. dilution of wastewater effluent, rainfall, temperature and level of sunlight).
The main objective of the research presented in this paper was to verify the occurrence and fate of different classes of 55 PPCPs during wastewater treatment. These were: pharmaceuticals (analgesic/anti-inflammatory drugs, antibiotics, antiepileptics, beta-adrenoceptor blocking drugs, lipid regulating agents, etc.), personal care products (sunscreen agents, preservatives and disinfectant/antiseptics), endocrine disruptors (bisphenol A and 4-tert-octylphenol) and illicit drugs (amphetamine, cocaine and benzoylecgonine). Studies previously presented have tended to concentrate on small subsets of these pollutants, whereas in reality treatment works will have to treat wastewaters containing a large variety of these potential pollutants and successfully remove them simultaneously with many other compounds. Therefore it is important to assess plants' effectiveness in the context of the substantial number of PPCPs treated simultaneously. In order to evaluate it the 5-month long monitoring program was undertaken in South Wales in the UK. The two contrasting WWTPs (utilising two different wastewater treatment processes: activated sludge and trickling filter beds) discharging treated wastewater in the two contrasting rivers (the River Taff – major river flowing through urbanised area and the River Ely – small river flowing through rural areas) were chosen for the research in order to better understand factors affecting the occurrence and fate of PPCPs in the environment. An assessment of the efficiency of PPCPs removal using two contrasting wastewater treatment technologies was undertaken. The impact of treated wastewater effluent on the quality of receiving waters was also investigated.
Section snippets
Chemicals and materials
Reference standards were obtained from Sigma–Aldrich (Gillingham, UK) and Sequoia Products Research Limited (Pangbourne, UK). Surrogate/internal standards (IS): phenacetin-ethoxy-1-13C (CAS no. 72156-72-0), caffeine-d9 (1,3,7-trimethyl-d9, CAS no. 72238-85-8), clofibric-d4 acid (4-chlorophenyl-d4, CAS no. 882-09-7), 3,4-dichlorobenzoic (2,5,6-d3) acid (CAS no. 350818-53-0), bisphenol A-d16 (CAS no. 96210-87-6) and 4-chlorophenol (2,3,5,6-d4, CAS no. 344298-84-6) were purchased from QMX
Results and discussion
Fifty-five PPCPs were studied and are presented in Table 2. In the selection process of pharmaceuticals, the number of prescriptions dispensed in the community in Wales (NHS (National Health Service), Prescription Cost Analysis, Wales, 2004) and the metabolism routes of pharmaceuticals were taken into consideration. The choice of personal care products was based on their high annual usage in a wide range of household products and concern over their possible effect on human and aquatic organisms
Conclusions
The manuscript presents the results obtained during the 5-month monitoring programme of PPCPs in wastewater and receiving waters in South Wales. Two contrasting wastewater treatment plants (WWTP Cilfynydd and WWTP Coslech) discharging treated wastewater effluent into two contrasting rivers (the rivers Taff and Ely) were the subject of the research. The research revealed that PPCPs are present at very high concentrations in raw sewage: average total 10 kg of 55 studied PPCPs in wastewater
Acknowledgments
This work was undertaken as a part of the EU Marie Curie Host Fellowship for the Transfer of Knowledge (contract number MTKD-CT-2004-509821). The authors would like to thank Welsh Water for assistance. Thanks also to Jim Hordern for help with sample collection.
References (48)
- et al.
Sci. Total Environ.
(2004) - et al.
J. Hazard Mater.
(2005) - et al.
Water Res.
(2006) - et al.
J. Chromatogr. A
(2007) - et al.
Water Res.
(2004) - et al.
Aquat. Toxicol.
(2006) - et al.
Chemosphere
(2007) - et al.
Sci. Total Environ.
(2007) - et al.
Environ. Pollut.
(2007) - et al.
Water Res.
(2005)