Simultaneous removal of As, Cd, Cr, Cu, Ni and Zn from stormwater using high-efficiency industrial sorbents: Effect of pH, contact time and humic acid

The effect of contact time, solution pH, and the presence of humic acid (HA) on the combined removal of As, Cd, Cr, Cu, Ni and Zn is investigated in batch tests using alumina, granulated activated carbon (GAC), and bauxsol coated sand (BCS) as sorbents. It is found that the equilibrium time for Cd, Cu, Ni and Zn is about 4h, while no clear equilibrium is observed for As and Cr. It is also found that increasing the pH until pH~8 enhanced Cd, Cu, Ni and Zn removal, but increasing the pH above this point had no major effect. In the cases of As and Cr, higher pH values (i.e. >7) decreased their removal. The presence of both 20 and 100mg/L HA suppressed the heavy metal removal except for Cr, and the suppression was higher at the higher HA concentration. Geochemical simulations suggest that this is due to the formation of dissolved HA-metal complexes preventing effective metal sorption. In the case of Cr, the presence of HA increased the removal when using alumina or BCS, while hindering the removal when using GAC. The findings show that the pH-value of the stormwater to be treated must be in the range of 6-7 in order to achieve removal of the full spectrum of metals. The results also show that natural organic matter may severely influence the removal efficiency, such that, for most metals the removal was reduced to the half, while for Cr it was increased to the double for alumina and BCS. Consequently, a properly working filter set up may not work properly anymore when receiving high loads of natural organic acids during the pollen season in spring or during defoliation in autumn and early winter, and during mixing of runoff with snowmelt having a low pH.

Evaluation of stormwater micropollutant source control and end-of-pipe control strategies using an uncertainty-calibrated integrated dynamic simulation model

The estimation of micropollutant (MP) fluxes in stormwater systems is a fundamental prerequisite when preparing strategies to reduce stormwater MP discharges to natural waters. Dynamic integrated models can be important tools in this step, as they can be used to integrate the limited data provided by monitoring campaigns and to evaluate the performance of different strategies based on model simulation results. This study presents an example where six different control strategies, including both source-control and end-of-pipe treatment, were compared. The comparison focused on fluxes of heavy metals (copper, zinc) and organic compounds (fluoranthene). MP fluxes were estimated by using an integrated dynamic model, in combination with stormwater quality measurements. MP sources were identified by using GIS land usage data, runoff quality was simulated by using a conceptual accumulation/washoff model, and a stormwater retention pond was simulated by using a dynamic treatment model based on MP inherent properties. Uncertainty in the results was estimated with a pseudo-Bayesian method. Despite the great uncertainty in the MP fluxes estimated by the runoff quality model, it was possible to compare the six scenarios in terms of discharged MP fluxes, compliance with water quality criteria, and sediment accumulation. Source-control strategies obtained better results in terms of reduction of MP emissions, but all the simulated strategies failed in fulfilling the criteria based on emission limit values. The results presented in this study shows how the efficiency of MP pollution control strategies can be quantified by combining advanced modeling tools (integrated stormwater quality model, uncertainty calibration).

Ecotoxicity of carbamazepine and its UV photolysis transformation products

Carbamazepine, an anti-epileptic pharmaceutical agent commonly found in wastewater, is highly recalcitrant to standard wastewater treatment practices. This study investigated the mixture toxicity of carbamazepine transformation products formed during ultraviolet (UV) photolysis using three standard ecotoxicity assays (representing bacteria, algae and crustaceans). UV-treatment of 6 mg L(-1) carbamazepine solution was carried out over a 120 min period and samples were removed periodically over the course of the experiment. Quantification results confirmed the degradation of carbamazepine throughout the treatment period, together with concurrent increases in acridine and acridone concentrations. Ecotoxicity was shown to increase in parallel with carbamazepine degradation indicating that the mixture of degradation products formed was more toxic than the parent compound, and all three ecotoxicity endpoints were still inhibited >60% relative to control populations upon dosing with 90+min UV-treated carbamazepine solution. Single compound toxicity testing also confirmed the higher toxicity of measured degradation products relative to the parent compound. These results show that transformation products considerably more toxic than carbamazepine itself may be produced during UV-treatment of wastewater effluents and/or photo-induced degradation of carbamazepine in natural waters. This study highlights the need to consider mixture toxicity and the formation and persistence of toxicologically relevant transformation products when assessing the environmental risks posed by pharmaceutical compounds.

Quantification of uncertainty in modelled partitioning and removal of heavy metals (Cu, Zn) in a stormwater retention pond and a biofilter

Strategies for reduction of micropollutant (MP) discharges from stormwater drainage systems require accurate estimation of the potential MP removal in stormwater treatment systems. However, the high uncertainty commonly affecting stormwater runoff quality modelling also influences stormwater treatment models. This study identified the major sources of uncertainty when estimating the removal of copper and zinc in a retention pond and a biofilter by using a conceptual dynamic model which estimates MP partitioning between the dissolved and particulate phases as well as environmental fate based on substance-inherent properties. The two systems differ in their main removal processes (settling and filtration/sorption, respectively) and in the time resolution of the available measurements (composite samples and pollutographs). The most sensitive model factors, identified by using Global Sensitivity Analysis (GSA), were related to the physical characteristics of the simulated systems (flow and water losses) and to the fate processes related to Total Suspended Solids (TSS). The model prediction bounds were estimated by using the Generalized Likelihood Uncertainty Estimation (GLUE) technique. Composite samples and pollutographs produced similar prediction bounds for the pond and the biofilter, suggesting a limited influence of the temporal resolution of samples on the model prediction bounds. GLUE highlighted model structural uncertainty when modelling the biofilter, due to disregard of plant-driven evapotranspiration, underestimation of sorption and neglect of oversaturation with respect to minerals/salts. The results of this study however illustrate the potential for the application of conceptual dynamic fate models base on substance-inherent properties, in combination with available datasets and statistical methods, to estimate the MP removal in different stormwater treatment systems and compare with environmental quality standards targeting the dissolved MP fraction.

Fate of citalopram during water treatment with O3, ClO2, UV and Fenton oxidation

In the present study we investigate the fate of citalopram (CIT) at neutral pH using advanced water treatment technologies that include O(3), ClO(2) oxidation, UV irradiation and Fenton oxidation. The ozonation resulted in 80% reduction after 30 min treatment. Oxidation with ClO(2) removed>90% CIT at a dosage of 0.1 mg L(-1). During UV irradiation 85% reduction was achieved after 5 min, while Fenton with addition of 14 mg L(-1) (Fe(2+)) resulted in 90% reduction of CIT. During these treatment experiments transformation products (TPs) were formed from CIT, where five compounds were identified by using high resolution and tandem mass spectrometry. Among these desmethyl-citalopram and citalopram N-oxide have been previously identified as human metabolites, while three are novel and published here for the first time. The three TPs are a hydroxylated dimethylamino-side chain derivative, a butyrolactone derivative and a defluorinated derivative of CIT.

A source classification framework supporting pollutant source mapping, pollutant release prediction, transport and load forecasting, and source control planning for urban environments

PURPOSE

Implementation of current European environmental legislation such as the Water Framework Directive requires access to comprehensive, well-structured pollutant source and release inventories. The aim of this work was to develop a Source Classification Framework (SCF) ideally suited for this purpose.

METHODS

Existing source classification systems were examined by a multidisciplinary research team, and an optimised SCF was developed. The performance and usability of the SCF were tested using a selection of 25 chemicals listed as priority pollutants in Europe.

RESULTS

The SCF is structured in the form of a relational database and incorporates both qualitative and quantitative source classification and release data. The system supports a wide range of pollution monitoring and management applications. The SCF functioned well in the performance test, which also revealed important gaps in priority pollutant release data.

CONCLUSIONS

The SCF provides a well-structured approach for European pollutant source and release classification and management. With further optimisation and demonstration testing, the SCF has the potential to be fully implemented throughout Europe.

Impact of solid retention time and nitrification capacity on the ability of activated sludge to remove pharmaceuticals

Removal of five acidic pharmaceuticals (ibuprofen, ketoprofen, naproxen, diclofenac and clofibric acid) by activated sludge from five municipal activated sludge treatment processes, with various sludge ages and nitrification capacities, was assessed through batch experiments. The increase in aerobic sludge age from 1-3 to 7 d seemed to be critical for the removal ofnaproxen and ketoprofen, with markedly higher rates of removal at sludge ages of 7 d or more. No removal was shown for diclofenac and clofibric acid, whereas high rates were observed for ibuprofen in all investigated sludges. Parallel examinations of activated sludge batches with and without allylthiourea (12 mg/L), an inhibitor ofammonia monooxygenase, showed minor to moderate influence on the removal rates of ketoprofen and naproxen. These results suggest that the removal rates of biodegradable pharmaceuticals in municipal activated sludge processes are strongly linked to the heterotrophic bacteria community.

Removal of pharmaceuticals in biologically treated wastewater by chlorine dioxide or peracetic acid

Removal of six active pharmaceutical ingredients in wastewater was investigated using chlorine dioxide (ClO2) or peracetic acid (PAA) as chemical oxidants. Four non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, diclofenac and mefenamic acid) and two lipid-regulating agents (gemfibrozil and clofibric acid, a metabolite of clofibrate) were used as target substances at 40 microg/L initial concentration. Three different wastewaters types originating from two wastewater treatment plants (WWTPs) were used. One wastewater was collected after extended nitrogen removal in activated sludge, one after treatment with high-loaded activated sludge without nitrification, and one from the final effluent from the same plant where nitrogen removal was made in trickling filters for nitrification and moving-bed biofilm reactors for denitrification following the high-loaded plant. Of the six investigated compounds, only clofibric acid and ibuprofen were not removed when treated with ClO2 up to 20 mg/L. With increasing PAA dose up to 50 mg/L, significant removal of most of the pharmaceuticals was observed except for the wastewater with the highest chemical oxygen demand (COD). This indicates that chemical oxidation with ClO2 could be used for tertiary treatment at WWTPs for active pharmaceutical ingredients, whereas PAA was not sufficiently efficient.

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to the pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process.

Occurrence and reduction of pharmaceuticals in the water phase at Swedish wastewater treatment plants

During the last decade, several screening programs for pharmaceuticals at Swedish wastewater treatment plants (WWTPs) have been conducted by research institutes, county councils, and wastewater treatment companies. In this study, influent and effluent concentrations compiled from these screening programs were used to assess the occurrence and reduction of non-antibiotic pharmaceuticals for human usage. The study is limited to full-scale WWTPs with biological treatment. Based on the data compiled, a total of 70 non-antibiotic pharmaceuticals have been detected, at concentrations ranging from a few ng/L to several μg/L, in the influent water. The influent concentrations were compared with the sale volumes and for many pharmaceuticals it was shown that only a small fraction of the amount sold reaches WWTPs as dissolved parent compounds. Pharmaceuticals with low reduction degrees at traditional WWTPs were identified. Further comparison based on the biological treatment showed lower reduction degrees for several pharmaceuticals in trickling filter plants compared with activated sludge plants with nitrogen removal.

Determination of sorption of seventy-five pharmaceuticals in sewage sludge

Sorption of 75 active pharmaceutical ingredients (APIs) to three different types of sludge (primary sludge, secondary sludge with short and long sludge age respectively) were investigated. To obtain the sorption isotherms batch studies with the APIs mixture were performed in four nominal concentrations to water containing 1 g of sludge. The range of APIs concentrations was between ng L(-1) to μg L(-1) which are found in the wastewater effluents. Isotherms were obtained for approximately 45 of the APIs, providing distribution coefficients for linear (Kd), Freundlich (Kf) and Langmuir (KL) isotherms. Kd, Kf and KL ranging between 7.1×10(4) and 3.8×10(7), 1.1×10(-2) and 6.1×10(4) and 9.2×10(-3) and 1.1 L kg(-1), respectively. The obtained coefficients were applied to estimate the fraction of APIs in the water phase (see Abstract Graphic). For 37 of the 75 APIs, the predicted presence in the liquid phase was estimated to >80%. 24 APIs were estimated to be present in the liquid phase between 20 and 80%, and 14 APIs were found to have <20% presence in the liquid phase, i.e. high affinity towards sludge. Furthermore, the effect of pH at values 6, 7 and 8 was evaluated using one way ANOVA-test. A significant difference in Kds due to pH changes were found for 6 of the APIs (variation 10-20%).

Modelling the fate of organic micropollutants in stormwater ponds

Urban water managers need to estimate the potential removal of organic micropollutants (MP) in stormwater treatment systems to support MP pollution control strategies. This study documents how the potential removal of organic MP in stormwater treatment systems can be quantified by using multimedia models. The fate of four different MP in a stormwater retention pond was simulated by applying two steady-state multimedia fate models (EPI Suite and SimpleBox) commonly applied in chemical risk assessment and a dynamic multimedia fate model (Stormwater Treatment Unit Model for Micro Pollutants--STUMP). The four simulated organic stormwater MP (iodopropynyl butylcarbamate--IPBC, benzene, glyphosate and pyrene) were selected according to their different urban sources and environmental fate. This ensures that the results can be extended to other relevant stormwater pollutants. All three models use substance inherent properties to calculate MP fate but differ in their ability to represent the small physical scale and high temporal variability of stormwater treatment systems. Therefore the three models generate different results. A Global Sensitivity Analysis (GSA) highlighted that settling/resuspension of particulate matter was the most sensitive process for the dynamic model. The uncertainty of the estimated MP fluxes can be reduced by calibrating the dynamic model against total suspended solids data. This reduction in uncertainty was more significant for the substances with strong tendency to sorb, i.e. glyphosate and pyrene and less significant for substances with a smaller tendency to sorb, i.e. IPBC and benzene. The results provide support to the elaboration of MP pollution control strategies by limiting the need for extensive and complex monitoring campaigns targeting the wide range of specific organic MP found in stormwater runoff.

Water management in cities of the future using emission control strategies for priority hazardous substances

Cities of the future face challenges with respect to the quantity and quality of water resources, and multiple managerial options need to be considered in order to safeguard urban surface water quality. In a recently completed project on 'Source control options for reducing emissions of Priority Pollutants' (ScorePP), seven emission control strategies (ECSs) were developed and tested within a semi-hypothetical case city (SHCC) to evaluate their potential to reduce the emission of selected European priority hazardous substances (PHSs) to surface waters. The ECSs included (1) business-as-usual, (2) full implementation of relevant European (EU) directives, (3) ECS2 in combination with voluntary options for household, municipalities and industry, (4) ECS2 combined with industrial treatment and best available technologies (BAT), (5) ECS2 in combination with stormwater and combined sewer overflow treatment, (6) ECS2 in combination with advanced wastewater treatment, and (7) combinations of ECS3-6. The SHCC approach was chosen to facilitate transparency, to allow compensating for data gaps and to decrease the level of uncertainty in the results. The selected PHSs: cadmium (Cd), hexachlorobenzene (HCB), nonylphenol (NP) and pentabromodiphenyl ether (PBDE) differ in their uses and environmental fate and therefore accumulate in surface waters to differing extents in response to the application of alternative ECS. To achieve the required reduction in PHS levels in urban waters the full implementation of existing EU regulation is prioritised and feasible combinations of managerial and technological options (source control and treatment) can be highly relevant for mitigating releases.

Presence and fate of priority substances in domestic greywater treatment and reuse systems

A wide range of household sources may potentially contribute to contaminant loads in domestic greywater. The ability of greywater treatment systems to act as emission control barriers for household micropollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of xenobiotic micropollutants in on-site greywater treatment systems. All of the investigated compounds are listed under the European Water Framework Directive as either "Priority Substances" (PS) or "Priority Hazardous Substances" (PHS). Significant knowledge gaps are identified. A wide range of potential treatment trains are available for greywater treatment and reuse but treatment efficiency data for priority substances and other micropollutants is very limited. Geochemical modelling indicates that PS/PHS removal during treatment is likely to be predominantly due to sludge/solid phase adsorption, with only minor contributions to the water phase. Many PS/PHS are resistant to biodegradation and as the majority of automated greywater treatment plants periodically discharge sludge to the municipal sewerage system, greywater treatment is unlikely to act as a comprehensive PS/PHS emission barrier. Hence, it is important to ensure that other source control options (e.g. eco-labeling, substance substitution, and regulatory controls) for household items continue to be pursued, in order that PS/PHS emissions from these sources are effectively reduced and/or phased out as required under the demands of the European Water Framework Directive.

Inter-laboratory exercise on steroid estrogens in aqueous samples

An inter-laboratory comparison exercise was organized among European laboratories, under the aegis of EU COST Action 636: "Xenobiotics in Urban Water Cycle". The objective was to evaluate the performance of testing laboratories determining "Endocrine Disrupting Compounds" (EDC) in various aqueous matrices. As the main task three steroid estrogens: 17alpha-ethinylestradiol, 17beta-estradiol and estrone were determined in four spiked aqueous matrices: tap water, river water and wastewater treatment plant influent and effluent using GC-MS and LC-MS/MS. Results were compared and discussed according to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones.

Ozonation of estrogenic chemicals in biologically treated sewage

The present study shows that ozonation of effluents from municipal wastewater treatment plants (WWTPs) is likely to be a future treatment solution to remove estrogens and xeno-estrogens. The required ozone dose and electrical energy for producing the ozone were determined in two WWTP effluents for removal of 17 estrogenic chemicals. The estrogenic compounds included parabens, industrial phenols, sunscreen chemicals, and steroid estrogens. The obtained values of Electrical Energy per Order (EEOs) for the treatment of the estrogens were in the range 0.14-1.1 kWh/m(3) corresponding to 1.7-14 g O3/m(3). It is furthermore suggested that UV-absorbance is a useful parameter for online control of the ozone dose in a full scale application since the absorbance of the WWTP effluents and the remaining concentration of the estrogens and xeno-estrogens correlated well with the applied ozone dose.

Dynamic stormwater treatment unit model for micropollutants (STUMP) based on substance inherent properties

Modelling the removal of micropollutants (MPs) in stormwater treatment systems is essential in a context that is characterized by a general lack of measurements. This paper presents an innovative dynamic model for the prediction of the removal of MPs in stormwater treatment systems (Stormwater Treatment Unit model for Micro Pollutants--STUMP). The model, based on a conceptual model of two-compartment (water and sediment) serial Continuous Stirred-Tank Reactors (CSTRs), can predict the fate of MPs based on their inherent properties, which are often the only information available regarding this kind of substances. The flexible structure of the model can be applied to a wide range of treatment units and substances. Based on the most relevant removal processes (settling, volatilization, sorption, biodegradation, and abiotic degradation), the model allows the dynamic simulation of the MP behaviour in the different compartments of stormwater treatment systems. The model was tested for heavy metals (copper and zinc) and organic substances (benzene and di(2-ethylhexyl)phthalate). The results show that volatilization plays a big role for removal of benzene while the removal of substances with high sorption capacity is mainly driven by settling. The model was proven to be able to predict the importance of the various fate processes for selected substances with different inherent properties. A thorough assessment of the influence of the various fate process parameters will allow a reliable assessment of the treatment performances for a wide range of MPs.

Presence of selected priority and personal care substances in an onsite bathroom greywater treatment facility

In recent years, concerns about climate change and the inefficient use and ongoing pollution of water resources have increased the political motivation to encourage water recycling. This has led to the widespread introduction of water saving measures and to advances in the decentralised treatment and reuse of wastewater. In particular, the treatment and reuse of greywater has received attention, although important information such as greywater substance loadings is still only rarely available. With the implementation of the European Water Framework Directive the focus on controlling and phasing-out Priority/Priority Hazardous Substances (PS/PHS) is growing, and it is vital to know their sources and flows in order to generate sustainable emission control strategies. The main objective of this study was to quantify the concentrations and loads of PS/PHS and personal care substances in bathroom greywater, and to thereby assess the contribution of household activities to municipal wastewater loads for these substances. Nickel and mercury may be sourced substantially from household activities as it shown in the paper that bathroom greywater contributed a significant proportion of the overall load of these substances at the municipal wastewater treatment plant. Organic matter in the influent greywater was found to be principally associated with large particles (>8 µm), however it was the dissolved and small sized particles that were predominantly removed in the treatment.

Fate of carbamazepine during water treatment

Seven transformation products of carbamazepine generated by at least one of three common water treatment technologies (UV-radiation, oxidation with chlorine dioxide (ClO2), and biological treatment with activated sludge) were identified by complementary use of ion trap, single quadrupole, and quadrupole-time-of-flight mass spectrometers. Acridine was formed during all of the three treatment processes, while acridine 9-carbaldehyde was identified as an intermediate during ClO2 oxidation. Further treatment of acridine with ClO2 produced 9-hydroxy-acridine. UV-treatment resulted in the formation of acridone, hydroxy-(9H,10H)-acridine-9-carbaldehyde, acridone-N-carbaldehyde, and 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione, while biological breakdown of acridine yielded acridone. In parallel, the transformation product iminostilbene was observed during sample analysis. In addition, this study compared the treatment technologies according to the removal of carbamazepine and the production and decay of its transformation products. The most successful method for the removal of carbamazepine was UV treatment while acridine and acridone were more susceptible to biological treatment. Therefore, based on the enhanced biodegradability of carbamazepine residues achieved by UV irradiation, we propose a coupled treatment technology involving an initial UV treatment step followed by biological treatment which may satisfactorily remove the parent compound and its transformation products.

Does the committee peer review select the best applicants for funding? An investigation of the selection process for two European molecular biology organization programmes

Does peer review fulfill its declared objective of identifying the best science and the best scientists? In order to answer this question we analyzed the Long-Term Fellowship and the Young Investigator programmes of the European Molecular Biology Organization. Both programmes aim to identify and support the best post doctoral fellows and young group leaders in the life sciences. We checked the association between the selection decisions and the scientific performance of the applicants. Our study involved publication and citation data for 668 applicants to the Long-Term Fellowship programme from the year 1998 (130 approved, 538 rejected) and 297 applicants to the Young Investigator programme (39 approved and 258 rejected applicants) from the years 2001 and 2002. If quantity and impact of research publications are used as a criterion for scientific achievement, the results of (zero-truncated) negative binomial models show that the peer review process indeed selects scientists who perform on a higher level than the rejected ones subsequent to application. We determined the extent of errors due to over-estimation (type I errors) and under-estimation (type 2 errors) of future scientific performance. Our statistical analyses point out that between 26% and 48% of the decisions made to award or reject an application show one of both error types. Even though for a part of the applicants, the selection committee did not correctly estimate the applicant's future performance, the results show a statistically significant association between selection decisions and the applicants' scientific achievements, if quantity and impact of research publications are used as a criterion for scientific achievement.

Substance flow analysis of parabens in Denmark complemented with a survey of presence and frequency in various commodities

Parabens are commonly used as preservatives due to anti-bactericidal and anti-fungicidal properties and they are ubiquitously present in personal care products, pharmaceuticals, food, industrial and domestic commodities. They are suspected of causing endocrine disrupting effects to aquatic organisms and adverse effects in humans and, thus, it is highly relevant to identify and quantify their sources and transportation pathways in the urban environment. Here a substance flow analysis (SFA) was performed in order to map and comprehend the substances' flow on a national basis. Many household commodities were found to contain parabens; cleaning detergents, slimy toys, and water-based paint. The presence and concentration of parabens are regulated in cosmetics and food. Use of parabens in pharmaceuticals as excipients is documented in Denmark. The import of parabens is increasing; although the number of industrial parabens containing commodities is decreasing and manufacturer reports phase-out of parabens. The vast majority of the paraben containing commodities has a durability of 18-30 months, thus the average lifetime of the paraben stock is perceived to be limited. The inflow was ca. 154 tonnes via pure chemicals and 7.2-73 tonnes via commodities in 2004. This corresponds to an average wastewater concentration of 640-900 microg/L, when excluding discharge to solid waste, soil, biodegradation and metabolism. This is in the same order of magnitudes as can be found in industrial wastewater but higher than that seen in domestic wastewater. The data needed for the SFA is sparse, dispersed, and difficult to access and associated with a great deal of uncertainty.

Photolysis and advanced oxidation treatment of estrogenic chemicals in tap water and treated sewage

The removal efficiency by photolysis and advanced oxidation (AOP) of some estrogeniccompounds was investigated in tap water and biologically treated sewage. The compoundsinvestigated included parabens, industrial phenols, sunscreen chemicals and steroid estrogens.Treatment experiments were performed using a UV lamp optimized for photochemicaltreatment in a flow through set-up. The effect of different concentrations of H2O2 anddifference between tap water and treated sewage was investigated for all compounds.The treatment effectiveness is evaluated based on the Electrical Energy per Order (EEO) (unitkWh/111e3), which is defined as the electrical energy consumed per unit volume of water treatedrequired for 90 % removal of the investigated compound.It was found that the removal efficiency was better in tap water than in wastewater which isdue to the shadow effect from the inorganic and organic substance in the wastewater. Further,it was found that the removal of all the compounds was dependent of the UV dose for bothtreatment methods. The energy required for 90% removal of the compounds was between 28kWh/111e3 ± 2.9 (butylparaben) and 1.2 kWh/ 111e3 (estrone) for the UY treatment. The AOPresults in a more unifom1 value of EEO, which is between 8. 7 kWh/m3 (bisphenol A andbenzophenone-7) and 1.8 kWh/m3 ( I 7a-ethynyl estradiol).The removal at different concentration of H2O2 was investigated and it was found thatremoval effectiveness increased with concentration until 60 mg/L, but decreased at I 00 mg/L,which may be caused by H2O2 scavenging the HO'-radicals.

High plasma IgE levels within the Scandinavian wolf population, and its implications for mammalian IgE homeostasis

Immunoglobulin E (IgE) serves as an important link between innate and adaptive immunity through its ability to bind high affinity receptors on mast cells and basophils. Large differences in IgE levels may here affect this important link, and IgE levels in natural non-domestic animal populations may therefore be very informative concerning the levels of IgE that this system have been balanced against during recent mammalian evolution. However, very few such studies have been performed. Here, we present an analysis of total IgE levels in 65 Scandinavian wolves: 57 free living (wild), and 8 wolves in captivity (Zoo). The 57 wild wolves correspond to approximately 30% of the entire wolf population in Sweden and Norway and thus represent a large fraction of the entire population, making this a unique sample from a wild canine population. The median IgE level in these wolves was 67 microg/ml, which is approximately twice the level seen in domestic dogs and more than 100 times the levels in non-atopic humans. The collected information from domestic and wild populations now indicate that the very low IgE levels observed in man and laboratory rodents are most likely an effect of a life in a relatively parasite free environment, and that total IgE levels under maximally stimulatory (normal) conditions may reach 100-200 microg/ml.

Selected stormwater priority pollutants: a European perspective

The chemical characteristics of stormwater are dependent on the nature of surfaces (roads, roofs etc.) with which it comes into contact during the runoff process as well as natural processes and anthropogenic activities in the catchments. The different types of pollutants may cause problems during utilisation, detention or discharge of stormwater to the environment and may pose specific demands to decentralised treatment. This paper proposes a scientifically justifiable list of selected stormwater priority pollutants (SSPP) to be used, e.g., for evaluation of the chemical risks occurring in different handling strategies. The SSPP-list consists of 25 pollutant parameters including eight of the priority pollutants currently identified in the European Water Framework Directive. It contains general water quality parameters (organic and suspended matter, nutrients and pH); metals (Cd, Cr, Cu, Ni, Pb, Pt and Zn); PAH (naphthalene, pyrene and benzo[a]pyrene); herbicides (pendimethalin, phenmedipham, glyphosate and terbutylazine); and other representative industrially derived compounds (nonylphenol ethoxylates, pentachlorophenol, di(2-ethylhexyl)phthalate, PCB-28 and methyl tert-butyl ether). Tools for flux modelling, enabling calculation of predicted environmental concentrations (PECs), and for ranking the susceptibility of a pollutant to removal within a range of structural stormwater treatment systems or best management practices (BMPs) have been developed, but further work is required to allow all SSPPs to be addressed in the development of future stormwater pollution control measures. In addition, the identified SSPPs should be considered for inclusion in stormwater related monitoring campaigns.

Identifying model pollutants to investigate biodegradation of hazardous XOCs in WWTPs

Xenobiotic organic compounds (XOCs) in wastewater treatment plant (WWTP) effluents might cause toxic effects in ecosystems. Several investigations have emphasized biodegradation as an important removal mechanism to reduce pollution with XOCs from WWTP effluents. The aim of the study was to design a screening tool to identify and select hazardous model pollutants for the further investigation of biodegradation in WWTPs. The screening tool consists of three criteria: The XOC is present in WWTP effluents, the XOC constitutes an intolerable risk in drinking water or the environment, and the XOC is expected to be biodegradable in WWTPs. The screening tool was tested on bisphenol A (BPA), carbamazepine (CBZ), di(2ethylhexyl)-phthalate (DEHP), 17beta-estradiol (E2), estrone (E1), 17alpha-ethinyloetradiol (EE2), ibuprofen, naproxen, nonylphenol (NP), and octylphenol (OP). BPA, DEHP, E2, E1, EE2, and NP passed all criteria in the screening tool and were selected as model pollutants. OP did not pass the filter and was rejected as model pollutant. CBZ, ibuprofen, and naproxen were not finally evaluated due to insufficient data.

Simultaneous removal of As, Cd, Cr, Cu, Ni and Zn from stormwater: experimental comparison of 11 different sorbents

The potential of using alumina, activated bauxsol-coated sand (ABCS), bark, bauxsol-coated sand (BCS), fly ash (FA), granulated activated carbon (GAC), granulated ferric hydroxide (GFH), iron oxide-coated sand (IOCS), natural zeolite (NZ), sand, and spinel (MgAl(2)O(4)) as sorbents for removing heavy metals from stormwater are investigated in the present study. The ability of the sorbents to remove a mixture of As, Cd, Cr, Cu, Ni and Zn from synthetic stormwater samples were evaluated in batch tests at a starting pH of 6.5. The metal speciation and saturation data is obtained using the PHREEQ-C geochemical model and used to elucidate the sorption data. It is found that BCS, FA, and spinel have significantly higher affinity towards heavy metals mainly present as cationic or non-charged species (i.e. Cd, Cu, Ni and Zn) compared to those present as anionic species (i.e. As and Cr). However, IOCS, NZ and sand have higher affinity towards As and Cr, while alumina has equally high affinity to all tested heavy metals. The Freundlich isotherm model is found to fit the data in many cases, but ill fitted results are also observed, especially for FA, BCS and GAC, possibly due to leaching of some metals from the sorbents (i.e. for FA) and oversaturated conditions making precipitation the dominant removal mechanism over sorption in batches with high heavy metal concentrations and pH. Calculated sorption constants (i.e. K(d)) are used to compare the overall heavy metal removal efficiency of the sorbents, which in a decreasing order are found to be: alumina, BCS, GFH, FA, GAC, spinel, ABCS, IOCS, NZ, bark, and sand. These findings are significant for future development of secondary filters for removal of dissolved heavy metals from stormwater runoff under realistic competitive conditions in terms of initial heavy metal concentrations, pH and ionic strength.

Estrogenic personal care products in a greywater reuse system

The occurrence and fate of parabens in a greywater system was assessed. The potential for removal of residual paraben concentrations in effluent greywater with chlorine dioxide was also investigated. The influent to the greywater plant was characterised by considerable variation, with concentrations from below the detection limit to 40 microg/L and the five commonly used parabens in consumer products were frequently detected. After the biological treatment only two paraben were detected with concentration from 65-120 ng/L. Chlorine dioxide treatment of the biologically treated effluent with dosages down to 0.75 mg/L resulted in more than 97% reduction of all parabens. Formation of the by-product chloroform was insignificant from the chlorine dioxide treatment.

A methodology for ranking and hazard identification of xenobiotic organic compounds in urban stormwater

The paper presents a novel methodology (RICH, Ranking and Identification of Chemical Hazards) for ranking and identification of xenobiotic organic compounds of environmental concern in stormwater discharged to surface water. The RICH method is illustrated as a funnel fitted with different filters that sort out problematic and hazardous compounds based on inherent physico-chemical and biological properties. The outcomes of the RICH procedure are separate lists for both water phase and solid phase associated compounds. These lists comprise: a justified list of compounds which can be disregarded in hazard/risk assessments, a justified list of stormwater priority pollutants which must be included in hazard/risk assessments, and a list of compounds which may be present in discharged stormwater, but cannot be evaluated due to lack of data. The procedure was applied to 233 xenobiotic organic chemicals (XOCs) of relevance for stormwater. Of these 233 compounds, 121 compounds were found to be priority pollutants with regard to solids phases (i.e. suspended solids, soil, or sediments) when stormwater is discharged to surface water and 56 compounds were found to be priority pollutants with regard to the water phase. For 11% of the potential stormwater priority pollutants the screening procedure could not be carried out due to lack of data on basic physico-chemical properties and/or data on bioaccumulation, resistance to biodegradation, and ecotoxicity. The tiered approach applied in the RICH procedure and the focus on the phases relevant for monitoring or risk assessment in the aquatic environment refines the list of "compounds of concern" when compared to the outcome of existing classification schemes. In this paper the RICH procedure is focused on effects in the aquatic environment exemplified with xenobiotic organic compounds (XOCs) found in urban stormwater, but it may be transferred to other environmental compartments and problems. Thus, the RICH procedure can be used as a stand-alone tool for selection of potential priority pollutants or it can be integrated in larger priority setting frameworks.

Transformations of dissolved organic matter in a landfill leachate--a size exclusion chromatography/mass spectrometric approach

The aim of the present study was to search for qualitative changes in the landfill leachate DOM along a groundwater gradient. The study was focused on DOM characteristics of importance for its interaction with pollutants, such as molecular weight distribution and aromaticity. It was concluded that the leachate DOM underwent substantial qualitative changes along the investigated gradient at the Vejen landfill, Denmark. The molecular weight decreased, the polydispersity increased, and the aromaticity varied with the lowest values found in the middle of the gradient. The high aromaticity in the end of the gradient may explain the higher DOM binding capacity towards hydrophobic compounds seen earlier in these samples. The relative abundance of ions with mass to charge ratio (m/z) of 600-1200 seemed to be very stable along the gradient, indicating that the observed qualitative changes of the DOM is mostly attributed to changes in the m/z 100-600 range. The DOM seemed to become more similar to fulvic acids present in uncontaminated groundwater with respect to molecular weight and polydispersity along the gradient.

Transfer of hydrophobic contaminants in urban runoff particles to benthic organisms estimated by an in vitro bioaccessibility test

An in vitro bioaccessibility test was applied for assessing the transfer of polycyclic aromatic hydrocarbons (PAHs) present in road dust, into benthic organisms living in a receiving water body. The road dust is supposed to be urban runoff particles under wet weather conditions. Sodium dodecyl sulfate (SDS) solution was used as a hypothetical gut fluid. Pyrene, fluoranthene and phenanthrene were the main PAH species in the SDS extractable fraction of road dust, as well as the whole extract. Benzo(ghi)perylene showed relatively low concentrations in the SDS extract in spite of a high concentration in the original dust. The PAH composition in benthic organisms (polychaetes) did not correspond with that of the surrounding sediment and the PAHs detected were also detected in high concentrations in the SDS extract of road dust. When testing the toxicity of the extracted contaminants by a standardised algal toxicity test, SDS extracts of a detention pond sediment showed higher toxicity than the pore water of the corresponding sediment. Sediment suspension showed a comparative toxicity with 0.1% SDS extract. From the results, the in vitro bioaccessibility test seems more suitable to evaluate the exposed contaminants than the traditional organic solvent extraction method and the SDS extracted fraction is applicable to toxicity tests reflecting the digestive process.

Generation of therapeutic antibody responses against IgE in dogs, an animal species with exceptionally high plasma IgE levels

Allergic diseases are common in dogs and the involvement of IgE in the pathogenesis of canine atopic dermatitis (CAD) and flea allergy dermatitis (FAD) is documented. However, many dogs do not achieve sufficient control of their allergic disease, and there is a great need for new treatment strategies. In order to address this issue we first needed to obtain a better picture of IgE-levels in dogs and how plasma IgE-levels are affected by breed, age and health status. IgE is normally present at diminutive concentrations in sera and detection by diagnostic methods has been a technical challenge. Here, we present a new in vitro assay for determining absolute levels of total IgE in sera from dogs. In a panel of 76 adult dogs diagnosed either as healthy or suffering from atopic dermatitis, autoimmunity or infection by skin parasites, we show that levels of IgE range from 1 to 41 microg/ml. This is almost 100 times the level observed in non-atopic humans. However, these exceptionally high IgE-levels in the dogs could not be correlated to either breed or health status. To address the issue of novel treatment strategies, the possibility of reducing the IgE-levels in nine Beagle dogs by immunization with a new therapeutic vaccine was investigated. High levels of anti-IgE antibodies were induced in all dogs, and the IgE-levels were subsequently decreased by a mean of 65%. This shows that the allergy vaccine is potent enough to break the tolerance against IgE, even when the initial IgE-levels are as high as those observed in dogs. Thus, the vaccination treatment may have the potential to serve as a future therapy for dogs with atopic diseases.

Chemical hazard identification and assessment tool for evaluation of stormwater priority pollutants

Assessment of chemical hazards is a critical issue, which have to be dealt with when evaluating different strategies for sustainable handling of stormwater. In the present study, a methodology for identifying the most critical and representative chemical pollutants was developed. A list of selected stormwater priority pollutants (SSPP-list) is the out-put from the procedure. Two different strategies for handling of stormwater were considered; discharge into a surface water recipient and infiltration. However, the same methodology can be used for other types of wastewater and other strategies for handling and treatment. A literature survey revealed that at least 656 xenobiotic organic compounds (XOCs) could be present in stormwater. In the next step, 233 XOCs were evaluated with respect to the potential for being hazardous towards either aquatic living organisms or humans, or causing technical or aesthetical problems. 121 XOCs were found have at least one of these negative effects, while 26 XOCs could not be assessed due to the lack of data. The hazard assessment showed that 40 XOCs had a PEC/PNEC ratio above one., e.g. they should be considered as priority pollutants. The final step is the expert judgement, which resulted in a final SSPP-list containing 16 selected priority pollutants.

A novel method for evaluating bioavailability of polycyclic aromatic hydrocarbons in sediments of an urban stream

Hydrophobic organic pollutants in urban wet weather discharges can accumulate in the sediments of receiving waters and may have adverse effects on the ecological system, especially on benthic organisms. Here, a novel method is developed for evaluating the bioavailability of such hydrophobic organic pollutants by considering the digestive guts in deposit-feeding polychaetes. We compared the amount of polycyclic aromatic hydrocarbons (PAHs) extracted by an organic solvent and by sodium dodecyl sulfate (SDS) solution (as a hypothetical digestive gut fluid of polychaetes) and interpreted the ratio of the two values as bioavailability. The sediment extracts were applied to bacterial acute toxicity tests and algal growth inhibition tests. Sediment samples were collected from an urban stream system receiving wet weather discharges. The bioavailability of the total amount of 12 PAHs in the sediments was in the range 14-38% based on the results from the GC/MS determination of the two different extracts. Lower molecular PAHs showed higher bioavailability compared to the higher molecular ones. The sediment extracts were shown to be toxic towards both algae and bacteria. The SDS extracts showed similar or higher toxicity in the two biotests compared to the organic solvent extracts in spite of their lower PAHs content.

Xenobiotic organic compounds in leachates from ten Danish MSW landfills--chemical analysis and toxicity tests

A monitoring program comprising chemical analysis and biological toxicity testing of leachate samples from 10 Danish landfills (six engineered and four uncontrolled) revealed the presence of 55 different xenobiotic organic compounds (XOCs) and 10 degradation products of XOCs. The compounds belong to the following groups: BTEX, C3-benzenes, bicyclo compounds, napthalenes, chlorinated aliphatics, phenols (chloro-, methyl-, dimethyl, nonyl-), pesticides, and phthalates. Concentrations of single XOCs ranged from <0.1 to 2220 microg/L. A pesticide screening including 101 different compounds resulted in detection of 18 pesticides and three degradation products. The findings of degradation products of toluene, phenols, phthalates, pesticides, and nonylphenol ethoxylates show that degradation occurred inside the landfills. In biotests with bacteria and algae it was found that the non-volatile organic compounds were toxic as the samples only needed to be pre-concentrated from 1.3 to 9.4 times to give 50% inhibition of the test organisms. One of the ten samples proved to be genotoxic in the umuC test after 141 times pre-concentration. A major part of the organic chemicals causing toxicity remains unknown and it is recommended to combine chemical analyses and biotests in future monitoring programs.

Identification of adjuvants that enhance the therapeutic antibody response to host IgE

In the development of a novel vaccine against atopic allergies, we have screened for adjuvants that enhance the therapeutic antibody response against self immunoglobulin E (IgE). The response against self IgE is induced by administration of a vaccine antigen, which contains both self and non-self IgE regions, together with an adjuvant. We evaluated five commonly used adjuvants; Freund's, aluminium hydroxide, ISCOMs, Montanide ISA 51 and Montanide ISA 720, and found that the mineral oil-based adjuvants; Montanide ISA 51 and Freund's induced at least 5-10-fold higher anti-self IgE titers than any of the other candidates. However, with one exception, Alum, the immune responses against the carrier, i.e. the non-self regions, were similar for all adjuvants, indicating that the ability to induce responses against self and non-self antigens differ among adjuvants. The responses against non-self IgE were more than 50-fold higher than antibody responses against self IgE in both the Freund's and Montanide 51-administered animals, indicating that the response against self molecules is markedly inhibited by tolerance-inducing mechanisms. Co-administration of Montanide ISA 51 with immuno-stimulatory substances from bacteria; muramyldipeptide (MDP), monophosphoryl-lipid A (MPL) or a formyl-methionine-containing tripeptide (fMLP), did not elevate the anti-self IgE response. Hence, adjuvants based on pure mineral oil without additional immuno-stimulatory substances appear to be the best adjuvant candidates in therapeutic vaccines aimed at regulating the in vivo levels of self-proteins.

Can degradation products be used as documentation for natural attenuation of phenoxy acids in groundwater?

In situ indicators of degradation are important tools in the demonstration of natural attenuation. A literature survey on the production history of phenoxy acids and degradation pathways has shown that metabolites of phenoxy acid herbicides also are impurities in the herbicide products, making the bare presence of these compounds useless as in situ indicators. These impurities can make up more than 30% of the herbicides. Degradation of phenoxy acids was demonstrated in microcosm experiments using groundwater and sediment contaminated with MCPP, dichlorprop, and related compounds such as other phenoxypropionic acids and chlorophenols. Field observations at two phenoxy acid-contaminated sites showed the occurrence of several impurities including metabolites in the groundwater. Neither the microcosm experiments nor the field observations verified that metabolites were actually produced or accumulated in situ. However, it was demonstrated that the impurity/parent herbicide ratios can be useful in situ indicators of degradation.

International evaluation of current and future requirements for environmental engineering education

The field of environmental engineering is developing as a result of changing environmental requirements. In response, environmental engineering education (E3) needs to ensure that it provides students with the necessary tools to address these challenges. In this paper the current status and future development of E3 is evaluated based on a questionnaire sent to universities and potential employers of E3 graduates. With increasing demands on environmental quality, the complexity of environmental engineering problems to be solved can be expected to increase. To find solutions environmental engineers will need to work in interdisciplinary teams. Based on the questionnaire there was a broad agreement that the best way to prepare students for these future challenges is to provide them with a fundamental education in basic sciences and related engineering fields. Many exciting developments in the environmental engineering profession will be located at the interface between engineering, science, and society. Aspects of all three areas need to be included in E3 and the student needs to be exposed to the tensions associated with linking the three.

Natural attenuation of xenobiotic organic compounds in a landfill leachate plume (Vejen, Denmark)

Demonstration of natural attenuation of xenobiotic organic compounds (XOCs) in landfill leachate plumes is a difficult task and still an emerging discipline within groundwater remediation. One of the early studies was made at the Vejen Landfill in Denmark in the late 1980s, which suggested that natural attenuation of XOCs took place under strongly anaerobic conditions within the first 150 m of the leachate plume. This paper reports on a revisit to the same plume 10 years later. Within the strongly anaerobic part of the plume, 49 groundwater samples were characterized with respect to redox-sensitive species and XOCs. The analytical procedures have been developed further and more compounds and lower detection limits were observed this time. In addition, the samples were screened for degradation intermediates and for toxicity. The plume showed fairly stationary features over the 10-year period except that the XOC level as well as the level of chloride and nonvolatile organic carbon (NVOC) in the plume had decreased somewhat. Most of the compounds studied were subject to degradation in addition to dilution. Exceptions were benzene, the herbicide Mecoprop (MCPP), and NVOC. In the early study, NVOC seemed to degrade in the first part of the plume, but this was no longer the case. Benzyl succinic acid (BSA) was for the first time identified in a leachate plume as a direct indicator, and as the only intermediate of toluene degradation. Toxicity measurements on solid phase-extracted (SPE) samples revealed that toxic compounds not analytically identified were still present in the plume, suggesting that toxicity measurements could be helpful in assessing natural attenuation in leachate plumes.

In situ biodegradation determined by carbon isotope fractionation of aromatic hydrocarbons in an anaerobic landfill leachate plume (Vejen, Denmark)

Concentrations and isotopic compositions (13C/12C) of aromatic hydrocarbons were determined in eight samples obtained from the strongly anoxic part of the leachate plume downgradient from the Vejen Landfill (Denmark), where methanogenic, sulfate-reducing and iron-reducing conditions were observed. Despite the heterogeneous distribution of the compounds in the plume, the isotope fractionation proved that ethylbenzene and m/p-xylene were subject to significant biodegradation within the strongly anoxic plume. The isotope fractionation factors (alphaC) for the degradation of the m/p-xylene (1.0015) and ethylbenzene (1.0021) obtained from the field observations were similar to factors previously determined for the anaerobic degradation of toluene and o-xylene in laboratory experiments, and suggest that in situ biodegradation is one major process controlling the fate of these contaminants in this aquifer. The isotope fractionation determined for 1,2,4-trimethylbenzene and 2-ethyltoluene suggested in situ biodegradation; however, the isotopic composition did not correlate well with the respective concentration as expressed by the Rayleigh equation. Some other compounds (1,2,3-trimethylbenzene, o-xylene, naphthalene and fenchone) did not show significant enrichments in delta13C values along the flow path. The compound concentrations were too low for accurate isotope analyses of benzene, toluene, 1- and 2-methylnaphthalene, while interferences in the chromatography made it impossible to evaluate the isotopic composition for 4-ethyltoluene, 1,3,5-trimethylbenzene and camphor. In addition to demonstrating the potential of assessing isotopic fractionation as a means for documenting the in situ biodegradation of complex mixtures of aromatic hydrocarbons in leachate plumes, this study also illustrates the difficulties for data interpretation in complex plumes and high analytical uncertainties for isotope analysis of organic compounds in low concentration ranges.

Mono- and diesters from o-phthalic acid in leachates from different European landfills

Leachates from 17 different landfills in Europe were analysed with respect to phthalates, i.e. phthalic acid diesters (PAEs) and their degradation products phthalic acid monoesters (PMEs) and ortho-phthalic acid (PA). Diesters are ubiquitous and the human possible exposure and potential to human health and environment has put them in focus. The aim of this study was to elucidate whether monoesters and phthalic acid could be traced in landfill leachates and in what concentrations they may be found. The results showed that phthalates were present in the majority of the leachates investigated. The monoesters appeared from 1 to 20 microg/L and phthalic acid 2-880 microg/L (one divergent value of 19 mg phthalic acid/L). Their parental diesters were observed from 1 to 460 microg/L. These observed occurrences of degradation products, of all diesters studied, support that they are degraded under the landfill conditions covered by this study. Thus, we have presented strong evidences to conclude that microorganisms in landfills degrade diesters released from formulations in a variety of products, including polyvinyl chloride (PVC) species.

Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV+ cartridges exhibited the best retention of phenols of the four sorbents examined, and was the only cartridge which a 1 L leachate sample could pass through. With the other cartridges, clogging made this impossible. The final method, which included 27 different phenols, gave detection limits of <0.1 microg/L (drinking water concentration limit for pesticides) for most phenols (25), and for 12 phenols <0.01 microg/L. Recovery rates (determined for four concentrations in the range 1-25 microg/L, two replicates of each) were in the range 79-104% (SD 1-12%), except for phenol (26+/-1.3%) and 2-methoxyphenol (62+/-4.2%). Up to 12 different phenols could be identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 microg/L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-microg/L to mg/L).

Generation of therapeutic antibody responses against IgE through vaccination

IgE is the central mediator in atopic allergies such as hay fever, eczema, and asthma; therefore, it is a prime target in the development of allergen-independent preventive treatments. We describe an active immunization strategy that has the potential to reduce IgE to a clinically significant extent. The active vaccine component is a chimeric IgE molecule, Cepsilon2-Cepsilon3-Cepsilon4. The receptor-binding target domain, Cepsilon3, is derived from the recipient species, whereas the flanking domains, Cepsilon2 and Cepsilon4, are derived from an evolutionarily distant mammal. The flanking domains have dual functions, acting both as structural support for the Cepsilon3 domain and to break T cell tolerance by providing foreign T cell epitopes. The efficacy of the vaccine was studied in an ovalbumin-sensitized rat model. Vaccination resulted in antibody responses against IgE in all rats and in a substantial reduction in serum IgE levels in three out of four strains. The skin reactivity upon allergen challenge was significantly reduced in vaccinated animals. The vaccine appears to be safe to use as an antigen. No cross-linking activity was observed in sera of vaccinated animals, and the response to vaccination was reversible with time. Our results suggest that active immunization against IgE has the potential to become a therapeutic method for humans.