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Chapter 12 Water quality analysis: Detection, fate, and behaviour, of selected trace organic pollutants at managed aquifer recharge sites Mathias Ernst, Arne Hein, Josef Asmin, Martin Krauss, Guido Fink, Juliane Hollender, Thomas Ternes, Claus Jørgensen, Martin Jekel and Christa S. McArdell 12.1 INTRODUCTION In treated municipal wastewater, residual organic compounds are of high relevance especially if water recycling and potable water reuse is envisaged. After biological treatment, such as the activated sludge process, some organic compounds remain that are either non-biodegradable, or are minimally biodegradable. If these chemicals are polar, they are commonly poorly absorbable, and are therefore identified as persistent polar organic compounds (also persistent polar pollutants, PPPs). In the last decade, there have been important analytical improvements in detecting trace levels of pollutants, and within the water reuse community, new “hazardous” compounds are frequently discussed. This includes consideration of which organic residuals are really of health concern, which transformation products can be generated, and what is their human and environmental impact? Within the present chapter relevant PPPs and their fate during (advanced) wastewater treatment and managed aquifer recharge are identified and discussed as results of measuring campaigns at technologically different demonstration sites within the European research project RECLAIM WATER. Such PPPs mainly belong in the group of pharmaceuticals but also industrial chemicals. Here antibiotics such as the macrolides and sulfonamides are of particular concern, because of the eco-toxicological potential of these parent micropollutants, and the potential threat posed by the build-up of antibiotic resistance genes. In addition to known multi-resistant bacteria such as Staphylococci, multi-resistant genes have recently been identified in the intestinal bacteria Citrobacter, Enterobacteriaceae and Escherichia coli (Patoli et al. 2010; Tao et al. 2010). Other organic substances of interest are the very persistent tracer compounds, such as the antiepileptic carbamazepine and the iodinated contrast media (ICM) diatrizoate (WateReuse report, 2008; Rauch-Williams et al. 2010). Such compounds can act as markers for anthropogenic activity, and be used to calibrate models of ground water flows; as reduction of concentration in the aquifer can only be explained by dilution (Gaser et al. 2011; Massmann et al. 2008). Another relevant group of substances are 1H-benzo-1,2,3-triazole (Benzotriazole, BTr) and its methylated analogues (tolyltriazole, TTri), these compounds are used as corrosion inhibitors in many industrial applications, in dishwashing agents, and in de-icing fluids for aircraft. After activated sludge treatment of sewage, the concentrations range from 7–18 µg/L BTri and 1–5µg/L TTri (Giger, 2006; Reemtsma, 2010). Within the “organic contaminants” work package of the RECLAIM WATER project (www.reclaim-water.org), a list of PPPs has been selected, analysed and assessed at managed aquifer recharge demonstration sites. There were two main goals for the “organic contaminants” study: (1) measure and identify relevant organic compounds, and (2) apply the new analytical protocol (protocol II) at 5 demonstration sites to study the fate and behaviour along the different treatment pathways. In conjunction with work package 1 (assessment and development of water reclamation technology), results from protocol II should identify the intensity of treatment needed to reduce levels of micropollutants. The four analytical partners BfG (German federal institute of hydrology), Eawag (Swiss Federal Institute of Aquatic Science and Technology, UNESCO-IHE (Delft institute for water education) and Technische Universität Berlin (TUB), developed the methods of protocol II and applied these to the 5 managed aquifer recharge sites (MAR). UNESCO-IHE however measured no specific micropollutant, but provided the methodology for characterisation of bulk organic matter (see Chapter 13). 198 Water Reclamation Technologies for Safe Managed Aquifer Recharge Selected water quality parameters The analytical program focused on more than 60 different organic compounds, most of which are known to be present in wastewater effluents at concentrations ranging from a few ng/L to several µg/L. These organic compounds commonly show limited biodegradability in the environment, together with a weak sorption tendency onto soil, thus they can often penetrate into unconfined aquifers. The selected compounds can be divided into seven groups: (i) antibiotics, (ii) antiepileptics (neutral drugs), (iii) iodinated contrast media, (iv) antipholgistics, analgesics, and lipid regulators (acidic drugs), (v) estrogens, (vi) nitrosamines, and (vii) other micropollutants. A list of the determined compounds within each of the seven groups, and the abbreviations used in the text, is given in Table 12.1. Table 12.1 Groups of compounds measured in the RECLAIM WATER project. Group Measured compounds i. Antibiotics Clarithromycin (CLA), erythromycin (ERY), anhydro-erythromycin (ERY-H2O), roxithromycin (ROX), azithromycin, sulfadiazine, sulfapyridine, sulfamethazine (SMZ), sulfadimethoxine, sulfamethoxazole (SMX), N-acetyl-sulfamethoxazole (N-Ac-SMX), trimethoprim (TMP) ii. Antiepileptics (neutral drugs) Carbamazepine, primidone iii. Iodinated contrast media (ICM) Iopamidol, iomeprol, iopromide, iohexol, diatrizoate, ioxitalamic acid, adsorbable organic iodine (AOI as bulk parameter) iv. Antipholgistics, analgesics, Ibuprofen, diclofenac, clofibric acid, naproxen, bezafibrate, fenoprofen, mephenamic lipid regulators (acidic drugs) acid, paracetamol v. Estrogens Estrone (E1), estradiol (E2), ethinylestradiol (EE2) vi. Nitrosamines N-nitrosodimethylamine (NDMA), -methylethylamine (NMEA), -diethylamine (NDEA), -di-n-propylamine (NDPA), -di-n-butylamine (NDBA), -diphenylamine (NDPhA), -morpholine (NMOR), -piperidine (NPIP), -pyrrolidine (NPYR) vii. Other micropollutants Benzotriazole (BT), 4-tolyltriazole (4TT), 5-tolyltriazole (5TT), bisphenol-A Within the antibiotics, the sulfonamide sulfamethoxazole (SMX) is a persistent compound. In Germany, SMX is used in both human medicine (53.6 tons / year, MUNLV-NRW 2007), and in veterinary medicine. Together with SMX, trimethoprim (TMP) is often applied in a ratio of 5:1, resulting in an in vitro synergistic antibacterial effect (cotrimoxazol). SMX is excreted in high amounts by patients, and its metabolite N-acetylsulfamethoxazole (N-Ac-SMX) can be converted back to SMX during wastewater treatment (Göbel et al. 2005). Therefore, both SMX and N-Ac-SMX need to be analyzed for correct mass balance calculations. The environmental fate of antibiotics and other pharmaceuticals during bank filtration have recently been discussed by Maeng et al. (2011) and the Water Research Foundation (2010). Among the antiepileptics, carbamazepine is a refractory compound, often detected in the ng/L range in groundwater, drinking waters respectively (Sacher et al. 2001; Massmann et al. 2006). The iodinated contrast media (ICM) in general is the group with the highest single compound concentration in treated municipal wastewater, even if µg/L concentration can be accessed for ethylene diamino tetraacetate (EDTA), benzotriazoles, diclofenac and sometimes carbamazepine as well (Reemtsma et al. 2006). The ICM are applied in high dosages for medical diagnostics, and are released from the patient by urine, nearly unchanged, within several hours of administration. The single ICM compounds often can be found in wastewater treatment effluent in concentrations ranging from several hundred ng/L to several µg/L. In particular, iopamidol and diatrizoate are quite resistant to natural removal mechanisms. As ICM contain iodine atoms, the sum content of iodine can be measured by the bulk organic parameter of absorbable organic iodine (AOI). AOI is determined to be 50% of the content of the ICM in source material. If this share decreases, the AOI allows distinction of whether the target compound was truly mineralized, or just transformed into new iodine containing organic molecules (Putschew, 2006). In the group of estrogens, endocrine disruption compounds (EDC) are frequently discussed within the scientific community and have received considerable public attention, due to news reports on feminisation of male fish. The present study focussed on the natural and synthetic hormones estrone (E1), estradiol (E2), and ethinylestradiol (EE2). However bisphenol-A (see group of other compounds) can show endocrine disruption effects too. Bisphenol A is often contained in plastics as a conditioner. The acid drug group, includes the well-known pain relieving drugs ibuprofen and diclofenac, which are often found in municipal effluents. Information on their behaviour during soil passage is given by Heberer et al. (2002) and Scheytt et al. (2007). Water quality analysis - trace organic pollutants 199 In the group of disinfection by-products, the nitrosamines and related compounds are of major concern. N-nitroso- dimethylamine (NDMA) is carcinogenic at very low concentrations, and is difficult to analyse. A new, reliable and accurate, method to detect nine nitrosamines was developed within the RECLAIM WATER project (Krauss & Hollender, 2008). The corrosion inhibitors benzotriazole, 4-tolyltriazole and 5-tolyltriazole, were measured; these compounds are found in high amounts in surface waters and also in groundwater (Giger et al. 2006; Reemtsma et al.