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In order to investigate the long-term fate of the herbicide chloridazon and its polar metabolites desphenyl-chloridazon and methyl-desphenyl-chloridazon, a lysimeter experiment was conducted. The plant protection product Pyramin WG, which contains chloridazon, was applied to a weighable, monolithic lysimeter and a backfilled, gravitation lysimeter. Leachate, soil and maize samples were analyzed, and the data from the monolithic lysimeter was used to simulate the transport through the soil profile with the pesticide leaching model Pesticide Emission Assessment at Regional and Local scales (PEARL). Chloridazon rapidly degraded to desphenyl-chloridazon and methyl-desphenyl-chloridazon. In leachate, chloridazon was therefore detected at concentrations up to 3.5 μg L−1, whereas the metabolites desphenyl-chloridazon and methyl-desphenyl-chloridazon were present for more than 2 years at higher concentrations up to 24 and 6.1 μg L−1. The concentrations of chloridazon in soil decreased significantly with depth and time, whereas both metabolites increased up to 370 and 16 μg kg−1. The high concentrations, even 916 days after the application, clearly indicate a continuous downward migration and degradation in soil. In maize, chloridazon and purely the metabolite desphenyl-chloridazon were detected in leaves and stems. Desphenyl-chloridazon was additionally found in grains. It was noted that the design and setup of the two lysimeters lead to significant variations in terms of transformation rate, soil retention time and accumulation by plants. A comparison of the simulated results and the leaching rates measured from the monolithic lysimeter yielded adequate results for the metabolites, but rather poor correlation for chloridazon. The results obtained suggest persistence and high dispersion of chloridazon, and especially its metabolites, in leachate and soil. In maize, the migration in leaves and stems and the accumulation by grains might be relevant in terms of food security.

The European Union has defined environmental quality standards (EQSs) for surface waters for priority substances and several other pollutants. Furthermore national EQSs for several chemicals are valid in Austria. The study investigated the occurrence of these compounds in municipal wastewater treatment plant (WWTP) effluents. In a first screening of 15 WWTPs relevant substances were identified, which subsequently were monitored in 9 WWTPs over 1 year (every 2 months). Out of 77 substances or groups of substances (including more than 90 substances) 13 were identified as potentially relevant in respect to water pollution and subjected to the monitoring, whereas most other compounds were detected in concentrations far below the respective EQS for surface waters and therefore not further considered. The preselected 13 compounds for monitoring were cadmium (Cd), nickel (Ni), copper (Cu), selenium (Se), zinc (Zn), diuron, polybrominated diphenyl ethers (PBDEs), di(ethyl-hydroxyl)phthalate (DEHP), tributyltin compounds (TBT), nonylphenoles (NP), adsorbable organic halogens (AOX) and the complexing agents ethylenediaminetetraacetic acid (EDTA) as well as nitrilotriacetic acid (NTA). In the effluents of WWTPs the concentrations of the priority substances Cd, NP, TBT and diuron frequently exceeded the respective EQS, whereas the concentrations for DEHP and Ni were below the respective EQS. The effluent concentrations for AOX, EDTA, NTA, Cu, Se and Zn frequently are in the range or above the Austrian EQS for surface waters. Besides diuron and EDTA all compounds are removed at least partially during wastewater treatment and for most substances the removal via the excess sludge is the major removal pathway. For the 13 compounds which were monitored in WWTP effluents population equivalent specific discharges were calculated. Since for many compounds no or only few information is available, these population equivalent specific discharges can be used to assess emissions from municipal WWTPs to surface waters as well as to make a first assessment of the impact of a discharge on surface waters chemical status. Comparing discharges and river pollution on a load basis, the influence of diffuse sources becomes obvious and therefore should also be taken into consideration in river management.

This study provides the first pan-European reconnaissance of the occurrence of polar organic persistent pollutants in European ground water. In total, 164 individual ground-water samples from 23 European Countries were collected and analysed (among others) for 59 selected organic compounds, comprising pharmaceuticals, antibiotics, pesticides (and their transformation products), perfluorinated acids (PFAs), benzotriazoles, hormones, alkylphenolics (endocrine disrupters), Caffeine, Diethyltoluamide (DEET), and Triclosan. The most relevant compounds in terms of frequency of detection and maximum concentrations detected were DEET (84%; 454 ng/L), Caffeine (83%; 189 ng/L), PFOA (66%; 39 ng/L), Atrazine (56%; 253 ng/L), Desethylatrazine (55%; 487 ng/L), 1H-Benzotriazole (53%; 1032 ng/L), Methylbenzotriazole (52%; 516 ng/L), Desethylterbutylazine (49%; 266 ng/L), PFOS (48%, 135 ng/L), Simazine (43%; 127 ng/L), Carbamazepine (42%; 390 ng/L), nonylphenoxy acetic acid (NPE(1)C) (42%; 11 microg/L), Bisphenol A (40%; 2.3 microg/L), PFHxS (35%; 19 ng/L), Terbutylazine (34%; 716 ng/L), Bentazone (32%; 11 microg/L), Propazine (32%; 25 ng/L), PFHpA (30%; 21 ng/L), 2,4-Dinitrophenol (29%; 122 ng/L), Diuron (29%; 279 ng/L), and Sulfamethoxazole (24%; 38 ng/L). The chemicals which were detected most frequently above the European ground water quality standard for pesticides of 0.1 microg/L were Chloridazon-desphenyl (26 samples), NPE(1)C (20), Bisphenol A (12), Benzotriazole (8), N,N'-Dimethylsulfamid (DMS) (8), Desethylatrazine (6), Nonylphenol (6), Chloridazon-methyldesphenyl (6), Methylbenzotriazole (5), Carbamazepine (4), and Bentazone (4). However, only 1.7% of all single analytical measurements (in total 8000) were above this threshold value of 0.1 microg/L; 7.3% were > than 10 ng/L.

The design criteria for wastewater treatment plants (WWTP) and the sludge retention time, respectively, have a significant impact on micropollutant removal. The upgrade of an Austrian municipal WWTP to nitrogen removal (best available technology, BAT) resulted in increased elimination of most of the analyzed micropollutants. Substances, such as bisphenol-A, 17alpha-ethinylestradiol and the antibiotics erythromycin and roxithromycin were only removed after the upgrade of the WWTP. Nevertheless, the BAT was not sufficient to completely eliminate these compounds. Thus, a pilot scale ozonation plant was installed for additional treatment of the effluent. The application of 0.6 g O(3) g DOC(-1) increased the removal of most of the micropollutants, especially for compounds that were not degraded in the previous biological process, as for example carbamazepine and diclofenac. These results indicated that the ozonation of WWTP effluent is a promising technology to further decrease emissions of micropollutants from the treatment process.

Several surfactants were monitored in treated and untreated sewage in nine municipal wastewater treatment plants (WWTPs) in western Austria. The nine sampled WWTPs cover a wide variety referring to size and applied treatment technology. The investigation focused on linear alkylbenzene sulphonate (LAS), quaternary ammonia compounds (QAC), nonylphenol (NP), octylphenol (OP), nonylphenolmono- (NP(1)EO) and -diethoxylates (NP(2)EO). Whereas LAS, NP, OP and NP(1,2)EO were analysed separately in the liquid phase and in the solid phase, the QACs were measured in the total sample. Total influent concentrations of LAS varied between 2.4 mg l(-1) up to 6.7 mg l(-1) whereas total effluent concentrations were in the lower microg l(-1) range (11-50 microg l(-1)). Whichever the type of treatment, a clear removal during treatment was observed. Solid liquid distribution coefficients K(d) were calculated for untreated sewage. The calculated K(d) values varied between 1300 and 3900 l kg(-1). OP was of minor importance with total influent concentrations below 1microg l(-1). NP and NP(1,2)EO were present in all analysed influents in concentrations between 1 and 35microg l(-1). Effluent concentrations were notably lower than the measured influent concentrations. K(d) values for NP varied between 500 and 6600 l kg(-1), for NP(1)EO between 800 and 2700 l kg(-1) and for NP(2)EO between 100 and 1800 l kg(-1). From the QACs several alkyl benzyl (BAC), dialkyl (DDAC) and trialkyl (ATAC) ammonium chlorides with varying alkyl chain lengths were analysed. Highest total concentrations in the influents to the WWTPs were observed for the BAC-C12 and the ATAC-C16 homologues. Effluent concentrations were notably lower compared to influent concentrations, indicating removal by adsorption and/or biodegradation. The influence of the removal by adsorption increased with increasing alkyl chain length.

The European Commission has presented a list of priority substances in addition to the Water Framework Directive (WFD) adopted in December 2000. The list of priority substances is a matter of continuous review hence other relevant substances identified as hazardous can be implemented for regulation. In that regard a group of potential hazardous substances, quaternary ammonium compounds (QAC) is selected for further investigation and assessment, as QAC are widely used as disinfectants, biocides, and detergents among a variety of other applications. This paper provides information on a general interdisciplinary approach for assessing the potential significance of chemical substances hitherto not described in a coherent way considering QACs as example. Benzalkonium chlorides (BAC) and dialkyldimethylammonium chlorides (DDAC) were selected as key compounds because of their product and application profiles, as well as their ecotoxicological properties. For basic environmental risk evaluation, QAC usage pattern, emissions from single source polluters, the fate in waste water treatment plants, concentrations in surface water and sediments, as well as ecotoxicological effective concentrations were analyzed in this study. Based on substrate characteristics and use pattern relevant single source polluters were identified and emission concentrations as well as loads discharged into the sewerage were determined. Effluents from hospitals and laundries but also from wellness resorts showed high effluent concentrations compared to municipal waste water. To describe the fate of QACs during waste water treatment, adsorption and degradation behavior were determined. Additionally the influence of QACs on biological processes, especially nitrification was assessed. Partition coefficient values (log kOC) for QACs were determined between 4.35 for DDAC-C10 and 5.69 for DDAC-C18 (data not shown) indicating the high adsorption potential of those substances to the activated sludge in the waste water treatment plants. Results for BAC-C12–18 were found to be in the same range. Concentrations for nitrification inhibition in waste water treatment plants lay above concentrations found in municipal waste water but in the range of concentrations discharged by single source polluters.

Soxhlet extraction and high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry detection (MS/MS) was used for the determination of selected quaternary ammonium compounds (QACs) in solid samples. The method was applied for the determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds in sediment and sludge samples in Austria. The overall method quantification limits range from 0.6 to 3 microg/kg for sediments and from 2 to 5 microg/kg for sewage sludges. Mean recoveries between 67% and 95% are achieved. In general sediments were especially contaminated by C12 chain benzalkonium chloride (BAC-C12) as well as by the long C-chain dialkyldimethylammonium chloride (DDAC-C18) with a maximum concentration of 3.6 mg/kg and 2.1mg/kg, respectively. Maxima of 27 mg/kg for DDAC-C10, 25 mg/kg for BAC-C12 and 23 mg/kg for BAC-C14 were determined for sludge samples. The sums of the 12 selected target compounds range from 22 mg/kg to 103 mg/kg in the sludge samples.

A method for simultaneous quantitative determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds (QACs) has been developed, validated and subsequently applied to real water samples in Austria. The method employs liquid-liquid extraction (LLE) followed by liquid chromatography/tandem mass spectrometry (LC-MS/MS), using electrospray ionization (ESI) in positive mode. The overall method quantification limits range from 4 to 19 ng/L for the enrichment of 500 mL water samples and analyte recoveries are between 80 and 99%. The method was applied to 62 of the respective water samples without filtration to avoid the loss of the analytes due to the high adsorption capacity of these compounds. Maxima in the mg/L range, especially in the wastewater of hospitals and laundries, could be detected for the selected target compounds.

Evidence that some alkylphenol polyethoxylates (APEOs) breakdown products are estrogenic has intensified the interest over their environmental and human health effects. Different quantitative methods but one single preparation and extraction method for the analysis of nonylphenol polyethoxylates (NPEOs) and their metabolites in water samples using solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with electrospray mass spectrometry detection (ESI-MS), are described. Quantification limits range about the low ng/l for the enrichment of 500 ml water samples and mean recoveries of 70% are achieved. These methods were subsequently applied to water samples coming from Austrian treatment plants.

In a study on the behaviour of pesticides in a soil–plant–water system, the quick, easy, cheap, effective, rugged and safe (QuEChERS) method for analysing pesticide or metabolite residues in soil and maize (leaves, roots and kernels) was optimized and validated. The pesticides bentazone, chloridazon and terbuthylazine and their metabolites bentazone-methyl, chloridazon-desphenyl, chloridazon-methyl-desphenyl, terbuthylazine-desethyl and terbuthylazine-2-hydroxy were selected in this study. The QuEChERS extracts obtained from soil and maize matrices and the collected leachate were analysed by liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/MS) using a high-performance liquid chromatography and an ultra-high-performance liquid chromatography (UHPLC) analytical column. As expected, shorter run times and higher sensitivity were achieved with the UHPLC column. Validation studies focused on recovery, repeatability, matrix effects, limits of detection and quantification. Recoveries (and repeatability relative standard deviation (RSD)) of the spiked samples were in the range of 55 to 98 % (7.4–18) in soil, 23 to 101 % (1.7–20) in maize and 82 to 105 % (4.4–25) in leachate. Quantification limits were lower than 3.0 μg kg−1 in soil, 7.3 μg kg−1 in maize and 0.080 μg l−1 in leachate.

Application of passive samplers is demonstrated for assessment of temporal and spatial trends of dissolved polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and priority metals in the middle stretch of the Danube river. Free dissolved concentrations of PAHs, measured using SPMD samplers, ranged from 5 to 72 ng/L. Dissolved PCBs in water were very low and they ranged from 5 to 16 pg/L. Concentration of mercury, cadmium, lead and nickel, measured using DGT samplers, were relatively constant along the monitored Danube stretch and in the range less than 0,1; 1-20; 18-74; and 173 -544 ng/L, respectively. Concentrations of PAHs decreased with increasing temperature, which reflects the seasonality in emissions to water. This has an implication for the design of future monitoring programs aimed at assessment of long term trends. For such analysis time series should be constructed of data from samples collected always in the same season of the year.

The occurrence of cashmerane (DPMI), celestolide, phantolide, traesolide (ATII), galaxolide (HHCB) and tonalide (AHTN) in sewage and surface waters and their fate during wastewater treatment and anaerobic sludge digestion is investigated. AHTN and HHCB are the most important representatives and influent concentrations of 0.41-1.8 and 0.9-13 μgL(-1) are observed. DPMI is detected in influent and effluent samples but in notably lower concentrations than AHTN and HHCB. Major sources of polycyclic musks are households, whereas industrial emitters seem to be of minor importance. This conclusion is supported by the analysis of selected industrial wastewaters (metal, textile and paper industry). Specific emissions of 0.36 ± 0.19 and 1.6 ± 1.0 mg cap(-1)d(-1) for AHTN and HHCB are calculated. Overall removal efficiencies between approx 50% and more than 95% are observed during biological wastewater treatment and removal with the excess sludge is the major removal pathway. Log K(D) values of 3.73-4.3 for AHTN, 3.87-4.34 for HHCB and 2.42-3.22 for DPMI are observed in secondary sludge. During sludge digestion no or only slight removal occurred. Mean polycyclic musk concentrations in digested sludge amounted to 1.9 ± 0.9 (AHTN), 14.2 ± 5.8 (HHCB), 0.8 ± 0.4 (ATII) and 0.2 ± 0.09 (DPMI) mgkg(-1) dry matter. In the receiving water systems a comparable distribution as during wastewater treatment is observed. AHTN, HHCB and DPMI are detected in surface waters (ND (not detected)

Dimethyl phthalate, diethyl phthalate, dibuthyl phthalate, butylbenzyl phthalate, bis(2-ethylbenzyl) phthalate (DEHP) and dioctyl phthalate were analysed in raw and treated wastewater as well as in surface runoff samples from traffic roads. All six investigated phthalates have been detected in all raw sewage samples, in nearly all wastewater treatment plant (WWTP) effluent samples and in all road runoff samples, with DEHP being the most abundant compound. DEHP inflow concentrations ranged 3.4-34 microg L(-1) and effluent concentrations 0.083-6.6 microg L(-1). In two WWTPs the fate of the phthalates was assessed by performing mass balances. Overall removal efficiencies of approx 95% were calculated. Removal is attributed to biotransformation and adsorption and the relevance of the removal via adsorption to sludge increased with increasing molecular weight and increasing lipophilic character of the compound. Except DEHP phthalate concentrations were higher in treated effluent samples than in road runoff. The environmental quality standard (EQS) for DEHP in surface waters is exceeded only in a few effluent samples, whereas nearly all road runoff samples were higher than the EQS. An assessment based on pure concentrations is not feasible and a mass balance based approach is required. Nevertheless the observations highlight the relevance of stormwater emissions and direct emissions from separated sewer systems to surface waters in relation to emissions from WWTPs and the necessity to consider all potential influences in the assessment of the status of surface water bodies with reference to xenobiotics.

Perfluorinated alkylated substances (PFAS) are of global interest due to their occurrence and persistency in the environment. This study includes surface waters and sediments for the analysis of eleven PFAS. The PFAS studied can be grouped in perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFS) and perfluoroalkyl sulfonamides (PFSA). The two most important compounds are perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). These two substances showed the most significant values for surface water samples with maximum concentrations of 21 ng l(-1) for PFOA and 37 ng l(-1) for PFOS. Sediment samples from seven Austrian lakes and the river Danube were studied. Whereas PFSA and PFS were not detected in any sediment sample PFCAs were detected in most of the lake samples in concentrations up to 1.7 microg kg(-1) dry wt. PFOA, perfluorohexanoic acid (PFHxA) and perfluoroheptanoic acid (PFHpA) were detected in all Danube river sediment samples in concentrations varying from 0.1 up to 5.1 microg kg(-1) dry wt. For the various sampling points the proportional mass flows deriving from wastewater discharges were calculated. Whereas only up to 10% of the average flow is discharged wastewater up to more than 50% of the PFAS mass flows in the rivers can be attributed to wastewater discharges. Besides wastewater different other pathways as emissions from point sources, further degradation of precursor products, runoff from contaminated sites or surface runoff as well as dry and wet deposition have to be considered as relevant sources for PFAS contamination in surface waters.

Effluents of wastewater treatment plants are relevant point sources for the emission of hazardous xenobiotic substances to the aquatic environment. One group of substances, which recently entered scientific and political discussions, is the group of the perfluorinated alkylated substances (PFAS). The most studied compounds from this group are perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS), which are the most important degradation products of PFAS. These two substances are known to be persistent, bioaccumulative and toxic (PBT). In the present study, eleven PFAS were investigated in effluents of municipal wastewater treatment plants (WWTP) and in industrial wastewaters. PFOS and PFOA proved to be the dominant compounds in all sampled wastewaters. Concentrations of up to 340 ng/L of PFOS and up to 220 ng/L of PFOA were observed. Besides these two compounds, perfluorohexanoic acid (PFHxA) was also present in nearly all effluents and maximum concentrations of up to 280 ng/L werde measured. Only N-ethylperfluorooctane sulphonamide (N-EtPFOSA) and its degradation/metabolisation product perfluorooctane sulphonamide (PFOSA) were either detected below the limit of quantification or were not even detected at all. Beside the effluents of the municipal WWTPs, nine industrial wastewaters from six different industrial branches were also investigated. Significantly, the highest emissions or PFOS were observed from metal industry whereas paper industry showed the highest PFOA emission. Several PFAS, especially perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA) and PFOS are predominantly emitted from industrial sources, with concentrations being a factor of 10 higher than those observed in the municipal WWTP effluents. Perfluorodecane sulphonate (PFDS), N-Et-PFOSA and PFOSA were not detected in any of the sampled industrial point sources.

Organophosphate esters are used in multitude of applications such as flame retardants, plasticizers and lubricants. In recent years concerns have been raised in regards to the environmental impact of some of the more commonly used phosphoric acid triesters, because many of them are toxic and persistent. Liquid-liquid extraction and ultrasound-assisted solvent extraction followed by liquid chromatography coupled to tandem mass spectrometry detection (LC-MS/MS) were used for the determination of nine priority organophosphate esters in waste and surface water, as well as in sediment samples for first time in Austria. Recoveries ranged from 63% to 94% in water and from 74 to 104% in sediment with estimated quantification limits between 2.6 and 7.9 ng/l in surface water, 4.1 and 13 ng/l in effluent waste water, and between 0.48 and 11 microg/kg in sediment. The validated method was applied to determine the occurrence of the selected organophosphorus flame retardants (OPFRs) and plasticizers in the aquatic environment of Austria. The impact of the discharge of waste water treatment plants into the receiving water bodies was also studied.

LC-MS/MS was used for determination of selected tetracyclines, sulfonamides, trimethoprim, and fluoroquinolones in manure samples of pig, chicken and turkey, as well as arable soils fertilized with manure. Recoveries from spiked samples ranged from 61 to 105%. Method quantification limits were set to 100 microg/kg for all substances. Analysis of 30 pig manure, 20 chicken and turkey dung, and 30 lyophilized soil samples taken in Austria revealed that in pig manure up to 46 mg/kg chlortetracycline, 29 mg/kg oxytetracycline and 23 mg/kg tetracycline could be detected. As representatives of the group of sulfonamides, sulfadimidine in pig manure and sulfadiazine in chicken and turkey dung were detected in significant amounts (maximum concentration, 20 and 91 mg/kg, respectively). Enrofloxacin was particularly observed in chicken and turkey samples. Positive detection of chlortetracycline, enrofloxacin, and ciprofloxacin, in soil samples should be outlined as most important results of this study.

In recent years perfluorinated alkylated substances (PFAS) have appeared as a new class of global pollutant. Besides being an industrially important group of compounds, PFAS are regarded as highly toxic and extraordinarily persistent chemicals that pervasively contaminate human blood and wildlife throughout the world. They are therefore regarded as PBT (persistent, bioaccumulative, and toxic) chemicals. Two comprehensive methods have been developed for determination of eleven of the most environmentally relevant PFAS (seven perfluoroalkylcarboxylates, two perfluoroalkylsulfonates, and two perfluoroctanesulfonamides) in aqueous samples. The compounds were isolated by liquid-liquid extraction (LLE) and solid-phase extraction (SPE), and identification and quantification of the target analytes were achieved by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS). With LLE detection limits ranged from 0.26 to 0.62 ng L(-1) for enrichment of 900-mL water samples; recovery of PFAS with a carbon chain longer than C7 was excellent (80-93%). With SPE, carboxylates with carbon chainsC10 could be extracted efficiently (70-98%) under acidic conditions, and PFOS and PFOSA could be extracted efficiently (81% and 96%, respectively) under basic conditions, resulting in MDLs between 0.25 and 0.64 ng L(-1). The LLE method was applied successfully to Austrian wastewater effluent samples.

Eight pharmaceuticals, two polycyclic musk fragrances and nine endocrine disrupting chemicals were analysed in several waste water treatment plants (WWTPs). A membrane bioreactor in pilot scale was operated at different solid retention times (SRTs) and the results obtained are compared to conventional activated sludge plants (CASP) operated at different SRTs. The SRT is an important design parameter and its impact on achievable treatment efficiencies was evaluated. Different behaviours were observed for the different investigated compounds. Some compounds as the antiepileptic drug carbamazepine were not removed in any of the sampled treatment facilities and effluent concentrations in the range of influent concentrations were measured. Other compounds as bisphenol-A, the analgesic ibuprofen or the lipid regulator bezafibrate were nearly completely removed (removal rates >90%). The operation of WWTPs with SRTs suitable for nitrogen removal (SRT>10 days at 10 degrees C) also increases the removal potential regarding selected micropollutants. No differences in treatment efficiencies were detected between the two treatment techniques. As in conventional WWTP also the removal potential of MBRs depends on the SRT. Ultrafiltration membranes do not allow any additional detention of the investigated substances due to size exclusion. However, MBRs achieve a high SRT within a compact reactor. Nonylphenolpolyehtoxylates were removed in higher extend in very low-loaded conventional WWTPs, due to variations of redox conditions, necessary for the degradation of those compounds.

Micropollutants as endocrine disrupting compounds (EDC) or pharmaceuticals are of increased interest in water pollution control. Wastewater treatment plant (WWTP) effluents are relevant point sources for residues of these compounds in the aquatic environment. The solids retention time (SRT) is one important parameter for the design of WWTPs, relating to growth rate of microorganisms and to effluent concentrations. If a specific substance is degraded in dependency on the SRT, a critical value for the sludge age can be determined. In WWTPs operating SRTs below this critical value, effluent concentrations in the range of influent concentrations or a distribution according to the adsorption equilibrium have to be expected, whereas in WWTPs operating at SRTs higher than the critical value degradation will occur. Critical SRTs were determined for different micropollutants, indicating that the design criteria based on the sludge age allows an estimation of emissions. Different treatment technologies as conventional activated sludge systems and a membrane bioreactor were considered and no significant differences in the treatment efficiency were detected when operated at comparable SRT. The results of the investigations lead to the conclusion that low effluent concentrations can be achieved in WWTPs operating SRTs higher than 10 days (referred to a temperature of 10 degrees C). This corresponds to the requirements for WWTPs situated in sensitive areas according to the urban wastewater directive of the European Community (91/271/EEC) in moderate climatic zones.

In order to address the Austrian situation concerning endocrine disrupting substances (EDS), a consortium called Austrian Research Cooperation on Endocrine Modulators (ARCEM) was established in 1999. Among several other issues that were investigated, ARCEM monitored more than 400 ground- and surface water samples for selected estrogenic hormones and industrial chemicals. Appropriate analytical methods were established using GC-HRMS for the detection of hormones and LC/MSMS for the detection of industrial chemicals. Since analytical results were forwarded for toxicological assessments within the programme, quantification limits below 0.1 ng/l (ethinyl estradiol) and 10 ng/l (industrial chemicals) were required depending on the NOEL of the individual compound. Results indicate that both hormones and industrial chemicals occur in the selected ground- and surface water sites in detectable concentrations. Three river sites were identified as being charged with noticeable concentrations of EDS. These results were verified by biological indications within the part of the ARCEM programme dealing with bio-indications.

Experten im osterreichischen Umweltbundesamt haben Gewasser auf Ruckstande von Arzneimittelwirkstoffen untersucht.