Xenoestrogens in the River Elbe and its tributaries

4-Alkylphenols, 4-alkylphenol ethoxylates, 4-alkylphenoxy carboxylates, bisphenol A, bisphenol F, 4-hydroxyacetophenon, 4-hydroxybenzoic acid and steroid hormones were analyzed in water samples of the River Elbe and its tributaries Schwarze Elster, Mulde, Saale, Havel and Schwinge. Additionally, freshly deposited sediments (FDS, composite samples) of the River Elbe and its tributaries were analyzed. The concentrations in water samples ranged from (in ng/l): bisphenol A 4 to 92, branched nonylphenol 13 to 87, branched nonylphenol ethoxylates <0.5 to 120, 4-tert. nonylphenoxy carboxylates <10 to 940 and 4-hydroxybenzoic acid 4 to 12. Steroid hormones were only detected in the Czech tributaries Jizera and Vltava in concentrations near the limit of quantification. In FDS samples the concentrations amounted to (in g/kg d.w.): bisphenol A 10-380, branched nonylphenol 27-430, branched nonylphenol ethoxylates 24-3700, nonylphenoxy carboxylates <50 and 4-hydroxybenzoic acid 23-4400. Increased bisphenol A concentrations were found in water and FDS samples taken from the Czech-German border at Schmilka and the mouth of the Schwinge (only water sample). According to studies conducted in the Elbe Estuary and the German Bight, the River Elbe must be considered as a major source of pollution for the North Sea in respect of the compounds analyzed. A comparison of bisphenol A concentrations, 4-alkylphenols and the corresponding ethoxylates analyzed in the River Elbe and its tributaries with those found in other German surface waters indicated a low level of contamination. The evaluation of the data based on LOEC-values indicated that the concentrations were well below the effectivity threshold for some 4-alkylphenols. According to recent ecotoxicological investigations, for example, with prosobranch snails, bisphenol A concentrations found in water samples of the River Elbe and its tributaries may well be detrimental to aquatic organisms. On the basis of the monitoring data and its implications for estrogenic potency the inclusion of bisphenol A in the list of priority substances (European Union Directive 2000/60/EC, Annex X) should be considered.     

Alkylphenols and their ethoxylates in seafood from the Tyrrhenian Sea

The present study reports the results of an investigation on occurrence of octylphenols (OPs), nonylphenols (NPs) and their respective ethoxylates (with 1-6 ethoxylic group) in aquatic species of commercial interest from the Tyrrhenian Sea. Samples were collected at Livorno, Fiumicino and Salerno commercial harbors, during September-October 2003. The data obtained showed that almost all of the tested compounds were found in all the samples. NP was generally detected at the highest concentrations. Among the tested species common to the three sampling sites, mullets and seabreams generally showed high values of total alkylphenols (APs) and alkylphenol ethoxylates (APEOs) (44-55 ng g(-1) and 27-525 ng g(-1) fw), yet, the maximum concentrations were found in shrimps from Fiumicino (1255 ng g(-1) fw). On the contrary, the lowest concentrations were observed in hakes and anchovies (34-36 ng g(-1) and 6-37 ng g(-1) fw). Tuna, exhibited very high concentrations of total alkylphenolic compounds (APEs) (889 ng g(-1) fw). Seafood from Fiumicino fishing area, which is under the influence of the River Tiber, showed a degree of contamination of at least one order of magnitude higher than the other two sites. On the basis of the results of this study, the corresponding daily intakes of NPs are much lower than the TDI proposed by the Danish Environmental Agency.     

Environmental and industrial factors relating to flavor tainting of fish in the upper Wisconsin river

Extracts from Large Toothed Aspen (Populous grandidenta Michx.) and Jack Pine (Pinus banksiana Lamb.) contained many odor compounds found in flavor-tainted walleye from the Wisconsin River, including alkylphenols. Aspen wood contained 8 ppb of 2-isopropylphenol, and river sediments also contained low ppb levels of many alkylphenols, including 2-isopropylphenol. Thiophenol and thiocresol which sporadically cause offensive sulfury taints in Wisconsin River fish were also found in river sediment. Quantitative analysis of fish for alkylphenols supported a hypothesis involving a food chain-mediated seasonal fluctuation of alkylphenol levels in fish. Thiophenols are postulated to be derived from pulp mill activities on the river.     

A sensitive and robust method for the determination of alkylphenol polyethoxylates and their carboxylic acids and their transformation in a trickling filter wastewater treatment plant

This paper presents a method for the determination of alkylphenols, alkylphenol polyethoxylates (APEO) and alkylphenol ethoxycarboxylates (APEC) in the aqueous and particulate phase of wastewater samples. Quantification was achieved by liquid chromatography-tandem mass spectrometry. The sensitivity of the method is demonstrated by low detection limits, in the dissolved phase 1.2-9.6ngl(-1) for alkylphenol, AP(1-3)EO and APEC and 0.1-4.1ngl(-1) for longer chain alkylphenol polyethoxylates. The method detection limit for particulate phase samples ranged from 6 to 60ngg(-1) for AP, AP(1-3)EO and APEC; with the longer chain APEO being from 0.5 to 20ngg(-1). Matrix effects were noted in complex matrix rich samples. There was a distinct change in the distribution of alkylphenol ethoxylates during biological treatment of the wastewater, with the major biotransformation products observed being carboxylated derivatives at concentrations of up to 1768ngl(-1). Shorter chain APEO were present in higher proportions in the suspended solids, due to their higher affinity to particulate matter compared to the long-chain oligomers.     

Pharmaceuticals in the river Elbe and its tributaries

Medicinal drugs were found to be ubiquitous in the river Elbe, its tributary the river Saale and in other tributaries at their points of entry into the Elbe. The distribution of concentration peaks along the investigated river stretches provides an indication that they are mainly due to the emission of treated waste water from municipal sewage treatment works. This leads to the conclusion that medicinal substances can be regarded as faecal indicators for water pollution caused by human activity. The main substances found in the Elbe in 1998 were diclofenac, ibuprofen and carbamazepine as well as various antibiotics and lipid regulators in the concentration range of <20-140 ng/l. The more thorough investigations carried out in 1999 and 2000 show that in addition to the drugs (phenazone, isopropyl-phenazone and paracetamol) metabolite concentrations contributed significantly to the total concentration of pharmaceuticals in the Elbe. The metamizole metabolites N-acetyl-4-aminoantipyrine (AAA) and N-formyl-4-aminoantipyrine (FAA) were found in concentrations from <20 to 939 ng/l. A multivariate statistical analysis revealed a high correlation in respect of the distribution of persistent substances. The metoprolol distribution throughout the Saale demonstrated that the tributaries cause either an increase (Weisse Elster, Unstrut, Ilm) or a reduction (Wipper, Bode) in the concentration, depending on the respective load of waste water. Wide scale sampling in Saxony during 2002 showed the ubiquitous occurrence of carbamazepine in surface waters. The ecotoxicological effects of this contamination cannot be assessed at present. This is due to the fact that no legal framework in respect of these medicinal drugs for human consumption has been established and therefore little research and no risk assessment has been carried out. Therefore it is urgently necessary to include at least the quantitatively most significant substances in the new assessment concept of the EC White Paper.     

Identification and quantitation of dinaphthylsulfones in particulate matter of the Elbe river,Germany. Part VI of organic compounds as contaminants of the Elbe river and its tributaries

Gas chromatographic-mass spectrometric (GC/MS) analysis of particulate matter of the Elbe river and its tributaries Havel, Spree and Mulde revealed a group of three dinaphthylsulfone isomers as sedimentary and suspended particulate matter (SPM) contaminants. The mass spectra of dinaphthylsulfones are characterized by the molecular ion (m/z 318), and the naphthyl fragment ion m/z 127. Losses of HSO(2) and C(10)H(7)O from the molecular ion lead to different mass spectra for each isomer. The gas phase infrared spectra exhibit isomer specific bands in the spectral region between 900 and 700 wave numbers. A synthetic mixture of dinaphthylsulfones was used for isomer identification and the assignment of the gas chromatographic retention behaviour of the dinaphthylsulfone isomers. Quantitative GC/MS analysis of dinaphthylsulfones in 44 sediment and SPM samples provided comprehensive information on the overall distribution and distinct sources of dinaphthylsulfones in the Elbe river drainage system. The results indicate emissions of these compounds over prolonged times and their environmental stability in anaerobic sediments.     

Meta-analysis of environmental contamination by alkylphenols

Alkylphenols and alkylphenol ethoxylates (APE) are toxics classified as endocrine-disrupting compounds; they are used in detergents, paints, herbicides, pesticides, emulsifiers, wetting and dispersing agents, antistatic agents, demulsifiers, and solubilizers. Many studies have reported the occurrence of alkylphenols in different environmental matrices, though none of these studies have yet to establish a comprehensive overview of such compounds in the water cycle within an urban environment. This review summarizes APE concentrations for all environmental media throughout the water cycle, from the atmosphere to receiving waters. Once the occurrence of compounds has been assessed for each environmental compartment (urban wastewater, wastewater treatment plants [WWTP], atmosphere, and the natural environment), data are examined in order to understand the fate of APE in the environment and establish their geographical and historical trends. From this database, it is clear that the environment in Europe is much more contaminated by APE compared to North America and developing countries, although these APE levels have been decreasing in the last decade. APE concentrations in the WWTP effluent of developed countries have decreased by a factor of 100 over the past 30?years. This study is aimed at identifying both the correlations existing between environmental compartments and the processes that influence the fate and transport of these contaminants in the environment. In industrial countries, the concentrations observed in waterways now represent the background level of contamination, which provides evidence of a past diffuse pollution in these countries, whereas sediment analyses conducted in developing countries show an increase in APE content over the last several years. Finally, similar trends have been observed in samples drawn from Europe and North America.     

Nonylphenols, nonylphenol-ethoxylates, linear alkylbenzenesulfonates (LAS) and bis (4-chlorophenyl)-sulfone in the German Bight of the North Sea.

Nonylphenols and nonylphenol-ethoxylates were detected in the water and sediment samples from the German Bight of the North Sea. Additionally bis (4-chlorophenyl)-sulfone and linear alkylbenzenesulfonates (LAS) were detected in marine waters. Proof of identification is given by comparison of spectral and chromatographic data from the compounds in sample extracts to those obtained from pure standards. In extracts obtained from water samples taken in 1990 and 1995 the concentrations of nonylphenols and bis-(4-chlorophenyl)-sulfone were compared for each year. The concentrations of nonylphenols in seawater varied from 0.7 to 4.4 ng/l while in the Elbe estuary about 33 ng/l were found. In water samples taken in 1998 nonylphenol-polyethoxylates could not be determined, whereas LAS concentrations of 30 ng/l were confirmed by HPLC-MS/MS. The concentrations of bis (4-chlorophenyl)-sulfone ranged from 0.18 to 2.2 ng/l. In sediment samples LAS concentrations of 39-109 ng/g dry weight were determined.     

Polycyclic aromatic hydrocarbons in suspended particulate matter and sediments from the Pearl River Estuary and adjacent coastal areas, China

The spatial distribution, composition, and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments and suspended particulate matter (SPM) from the Pearl River Estuary and adjacent coastal areas were examined. Total PAH concentrations varied from 189 to 637 ng/g in sediments and 422 to 1,850 ng/g in SPM. PAHs were dominated by 5,6-ring compounds in sediments and by 2,3-ring compounds in SPM samples. Assessment of PAH sources suggested that biomass and coal combustion is the major PAH source to the outer part of the estuary sediments and that petroleum combustion is the major PAH source to the inner part of estuary sediments. As for SPM samples, PAH isomer pair ratios indicated multiple (petroleum, petroleum combustion, and biomass and coal combustion) PAH sources, and significant temporal variations could exist for the sources of water column PAHs in the study area. The distribution of perylene in SPM samples indicated that the river was the dominant source of perylene in SPM and that perylene could be taken as an index to assess the contribution of river inflow to the total PAHs in SPM samples. The high concentration of perylene in the sediment was indicative of an in situ biogenic origin.     

Seasonal variation of hydrophobic organic contaminant concentrations in the water-column of the Seine Estuary and their transfer to a planktonic species Eurytemora affinis (Calanoïd, copepod). Part 2: Alkylphenol-polyethoxylates

The occurrence and fate of alkylphenols in various matrices of the Seine River Estuary were studied. Nonylylphenols (NP) and nonylphenol polethoxylates (NPEs) were monitored in surface dissolved water, suspended particulate matter (SPM) and in a copepod, Eurytemora affinis from November 2002 to January 2004. NPs, nonylphenol mono and diethoxylates (NP1EO, NP2EO) and nonylphenol-ethoxy-acetic-acid (NP1EC) were detected and measured in all dissolved water and SPM samples whereas nonylphenoxy-acetic-acid (NP2EC) was only found sporadically in dissolved water samples. Seasonal variation of total concentrations of NPs and NPEs, ranging, respectively from 399 to 2214ngl(-1) and from 405 to 9636ngg(-1), were measured in the dissolved water and in the SPM. Significant decreases were observed in the water-column during the maximum biological activity periods in spring and autumn. Furthermore, increasing levels were observed in the SPM during the winter period. High concentrations of NP1EO and NP were detected in all copepod samples, ranging from 3423 to 6406ngg(-1). This study is the first to report high levels of endocrine disruptors in estuarine copepods.     

Degradation of octylphenol and nonylphenol by ozone - part I: direct reaction

This aqueous reaction between ozone and two alkylphenols (APs), namely octylphenol (OP) and nonylphenol (NP), has been investigated. Both compounds are important endocrine disrupting chemicals, which arise from the biodegradation of alkylphenol ethoxylates and are often found at relatively high concentrations in wastewater effluents. In this paper the results of an experimental study are presented which provide values for the reaction rate constants between molecular ozone and undissociated OP and NP, and overall reaction rate constants for the degradation of the two APs at pH values in the range of 7-9. The kinetic rate constants for OP and NP degradation by molecular ozone were 4.33(+/-0.18) x 10(4) and 3.90(+/-0.10) x 10(4) M(-1) s(-1), and the reaction stoichiometry was similar in both cases and equal to approximately 1.3:1 ([O3]:[AP]). The overall second order reaction rate constants for the two APs increased significantly with increasing pH, which is believed to be mainly due to the increasing influence of indirect radical reaction with increasing pH; this aspect is considered in more detail in a companion paper. A preliminary investigation of the reaction mechanism suggests that an initial product of ozonation is hydroxyl-alkyl phenol.     

Assessing estrogenic activity in surface water and sediment of the Liao River system in northeast China using combined chemical and biological tools

This paper investigated some selected estrogenic compounds (4-t-octylphenol: 4-t-OP; 4-nonylphenols: 4-NP; bisphenol-A: BPA; diethylstilbestrol: DES; estrone: E1; 17β-estradiol: E2; 17α-Ethinylestradiol: EE2; triclosan: TCS) and estrogenicity in the Liao River system using the combined chemical and in vitro yeast screen bioassay and assessed their ecological risks to aquatic organisms. The estrogenic compounds 4-t-OP, 4-NP, BPA, E1, E2 and TCS were detected in most of the samples, with their concentrations up to 52.1 2065.7, 755.6, 55.8, 7.4 and 81.3 ng/L in water, and up to 8.6, 558.4, 33.8, 7.9, <LOQ and 33.9 ng/g in sediment, respectively. However, DES and EE2 were not detected in the Liao River. The estrogen equivalents (EEQ) of the water and sediment samples were also measured by the bioassay. High estrogenic risks to aquatic organisms were found in the river sections of metropolitan areas and the lower reach of the river system.     

Perfluorinated compounds in the Pearl River and Yangtze River of China

A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/l and <0.01–14 ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0–260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9–26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.     

Atmospheric concentrations and air-sea exchanges of nonylphenol, tertiary octylphenol and nonylphenol monoethoxylate in the North Sea

Concentrations of nonylphenol isomers (NP), tertiary octylphenol (t-OP) and nonylphenol monoethoxylate isomers (NP1EO) have been simultaneously determined in the sea water and atmosphere of the North Sea. A decreasing concentration profile appeared following the distance increasing from the coast to the central part of the North Sea. Air-sea exchanges of t-OP and NP were estimated using the two-film resistance model based upon relative air-water concentrations and experimentally derived Henry's law constant. The average of air-sea exchange fluxes was -12+/-6 ng m(-2)day(-1) for t-OP and -39+/-19 ng m(-2)day(-1) for NP, which indicates a net deposition is occurring. These results suggest that the air-sea vapour exchange is an important process that intervenes in the mass balance of alkylphenols in the North Sea.     

Spatial distribution and partitioning of polychlorinated biphenyl and organochlorine pesticide in water and sediment from Sarno River and Estuary,Southern Italy

The Sarno River is nicknamed “the most polluted river in Europe”. The main goal of this study is to enhance our knowledge on the Sarno River water and sediment quality and on its environmental impact on the gulf of Naples (Tyrrhenian Sea, Central Mediterranean Sea) in order to become a useful assessment tool for the regional administrations. For these reasons, 32 selected polychlorinated biphenyls (PCBs) and aldrin, α-BHC, β-BHC, δ-BHC, γ-BHC (lindane), 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulphate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide (isomer B) and methoxychlor were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments. Total concentrations of PCBs ranged from 1.4 to 24.9 ng L^?1 in water (sum of DP and SPM) and from 1.01 to 42.54 ng g^?1 in sediment samples. The concentrations of total organochlorine pesticides (OCPs) obtained in water (sum of DP and SPM) ranged from 0.54 to 7.32 ng L^?1 and from 0.08 to 5.99 ng g^?1 in sediment samples. Contaminant discharges of PCBs and OCPs into the sea were calculated in about 1,247 g day^?1 (948 g day^?1 of PCBs and 326 g day^?1 of OCPs), showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea.     

Distribution patterns of nitrobenzenes and polychlorinated biphenyls in water, suspended particulate matter and sediment from mid- and down-stream of the Yellow River (China)

Samples of water, suspended particulate matter (SPM) and sediment were collected from mid- and down-stream of the Yellow River. The distribution and concentration of 10 nitroaromatic compounds and polychlorinated biphenyls (PCBs) were extensively studied. The total concentration of 10 nitrobenzenes (SigmaNBs) varied from 0.269 to 9.052 microg l(-1) in water, from 2.916 to 164.4 microg kg(-1) dry weight in SPM, and from 0.954 to 14.72 microg kg(-1) dry weight in sediment. PCBs associated with the sediments, measured as the summed responses of Aroclor 1242, 1248, 1254, 1260 (in comparison to those of a standard 1:1:1:1 mixture), were found to be in the range of non-detectable to 5.98 microg kg(-1). In the samples collected, various PCB congeners showed similar distribution characteristics with congeners containing 3-5 chlorine atoms accounting for more than 96.4% of total PCB. In most of the samples, PCB concentrations occurred in the order: TetraCB > TriCB > PentaCB. Levels of SigmaNBs in the Yellow River were relatively low in comparison with values reported from other river and marine systems, and PCB levels were comparatively low. Relative to the PCBs, SigmaNBs showed significantly more difference among the various stations, presumably due to the influence of different pollution sources. No obvious correlation was observed between the pollutant concentrations and either the TOC or the grain size of the sediments.     

Distribution of polycyclic aromatic hydrocarbons in water, suspended particulate matter and sediment from Daliao River watershed, China

This study investigated the spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in surface water, suspended particulate matter (SPM) and sediment of Daliao River watershed composed of the Hun River, Taizi River, and Daliao River. The sources of PAHs were evaluated employing ratios of specific PAHs compounds and principal component analysis (PCA). The total concentrations of PAHs ranged from 946.1 to 13448.5 ng l(-1) in surface water, from 317.5 to 238518.7 ng g(-1) dry weight in SPM, and from 61.9 to 840.5 ng g(-1) dry weight in sediments. The levels of PAHs are relatively higher in water and SPM, and lower in sediments, in comparison with those reported for other rivers and marine systems around the world. The composition of PAHs in these mediums was mainly 4-6 rings PAHs. The higher contents of low molecular weight PAHs in the water and SPM suggest a relatively recent local source of PAHs, entered into the river via wastewater discharge and atmospheric way. On the other hand, the heavy pollution of PAHs in sediment and water near heavy industrial area suggests that PAHs have been released from industrial wastewater.     

Toxicity on crustaceans and endocrine disrupting activity on Saccharomyces cerevisiae of eight alkylphenols

In the last few years many concerns have been raised regarding the environmental safety of alkylphenol polyethoxylate surfactants (APnEOs).They are widely used in detergents, paints, herbicides and many other formulated products. It has been estimated that 60% of APnEOs end up in the aquatic environment; they are biodegradable and transformed into alkylphenols, such as nonylphenol and octylphenol that are hydrophobic and tend to accumulate. In the present study, acute and chronic aquatic toxicity and the estrogenic activity of the following eight alkylphenols were assessed: 4-nonylphenol, 4-octylphenol, 4-nonylphenol-10-ethoxylate, 4-tert-octylphenol, POE (1 to 2)-nonylphenol, POE (6)-nonylphenol, POE (3)-tert-octylphenol and POE (9 to 10)-tert-octylphenol. The toxic potential was measured on the crustaceans Daphnia magna and Ceriodaphnia dubia, while the estrogenic activity was determined by using the YES-test with the strain Saccharomyces cerevisiae RMY326. The results showed that the exposure of crustaceans to the eight xenoestrogens investigated caused both acute and chronic effects. The EC50 values found for C. dubia at 48 h were compared to D. magna at 24h and, gave a first indication about the toxic activity of the compounds investigated, that is better expressed in the long-term. In fact, chronic data showed a strong increase in toxicity with EC50 values one or two orders of magnitude lower than the acute values. The results of the YES-test showed that nonylphenol, octylphenol and 4-tert-octylphenol were the most estrogenic and the bioassay was able to detect their estrogenicity at very low concentrations (ng-microg/l).     

Endocrine disruptors in freshwater streams of Hesse, Germany: changes in concentration levels in the time span from 2003 to 2005

Four small freshwater streams in the region known as Hessisches Ried in Germany were investigated with respect to the temporal and spatial concentration variations of the endocrine disruptors bisphenol A (BPA), 4-tert-octylphenol (4-tert-OP), and the technical isomer mixture of 4-nonylphenol (tech.-4-NP). Measured concentrations of the target compounds in the river water samples ranged from <20 ng/l to 1927 ng/l, <10 ng/l to 770 ng/l, and <10 ng/l to 420 ng/l for BPA, 4-tert-OP and tech.-4-NP, respectively. BPA levels were, with the exception of two samples, below the predicted no-effect concentration (PNEC) for water organisms. Tech.-4-NP concentrations showed a significant tendency of decreasing concentrations during the sampling period. This is mainly attributed to the implementation of the European Directive 2003/53/EG, which restricts both the marketing and use of nonylphenols. Results from the analysis of additionally collected water samples from sewage treatment plant (STP) effluents indicate that the STPs cannot be the only sources for tech.-4-NP found in the river water.     

Removal of a broad range of surfactants from municipal wastewater--comparison between membrane bioreactor and conventional activated sludge treatment

Elimination of alkylphenol ethoxylates (APEO) and their degradation products (alkylphenols and alkylphenoxy carboxylates), as well as linear alkylbenzene sulfonates (LAS) and coconut diethanol amides (CDEA), was studied in a pilot plant membrane bioreactor (MBR) working in parallel to a full-scale wastewater treatment plant (WWTP) using conventional activated sludge (CAS). In the CAS system 87% of parent long ethoxy chain NPEOs were eliminated, but their decomposition yielded persistent acidic and neutral metabolites which were poorly removed. The elimination of short ethoxy chain NPEOs (NP(1)EO and NP(2)EO) averaged 50%, whereas nonylphenoxy carboxylates (NPECs) showed an increase in concentrations with respect to the ones measured in influent samples. Nonylphenol (NP) was the only nonylphenolic compound efficiently removed (96%) in the CAS treatment. On the other hand, MBR showed good performance in removing nonylphenolic compounds with an overall elimination of 94% for the total pool of NPEO derived compounds (in comparison of 54%-overall elimination in the CAS). The elimination of individual compounds in the MBR was as follows: 97% for parent, long ethoxy chain NPEOs, 90% for short ethoxy chain NPEOs, 73% for NPECs, and 96% for NP. Consequently, the residual concentrations were in the low mug/l level or below it. LAS and CDEA showed similar elimination in the both wastewater treatment systems that were investigated, and no significant differences were observed between the two treatment processes. Nevertheless, for all studied compounds the MBR effluent concentrations were consistently lower and independent of the influent concentrations. Additionally, MBR effluent quality in terms of chemical oxygen demand (COD), NH(4)(+) concentration and total suspended solids (TSS) was always superior to the ones of the CAS and also independent of the influent quality, which demonstrates high potential of MBRs in the treatment of municipal wastewaters.