Pollutant source or sink? Adsorption and mobilization of PFOS and PFOA from sediments in a large shallow lake with extended reed belt.

In this study, we i) assessed the occurrence of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in sediments, pore water, and bulk water from three different areas in Lake Neusiedl, Austria, and ii) investigated mechanisms regulating adsorption and remobilization of these substances under different conditions via multiple lab-scale experiments. The adsorption capacity was mainly influenced by sediments' organic matter content, oxide composition, and pre-loading. Results suggest that a further increase of PFAS-concentrations in the open lake can be partly buffered by sediment transport to the littoral zone and adsorption to sediments in the extended reed belt. But, under current conditions, the conducted experiments revealed a real risk for mobilization of PFOS and PFOA from reed belt sediments that may lead to their transport back into the lake. The amount of desorbed PFAS is primarily dependent on water/sediment- or pore water/water-ratios and the concentration gradient. In contrast, water matrix characteristics and oxygen levels played a minor role in partitioning. The highest risk for remobilizing PFOS and PFOA was observed in experiments with sediments taken near the only major tributary to the lake (river Wulka), which had the highest pre-loading. The following management advice for water transport between high and low polluted areas can be derived based on the results. First, to reduce emissions into Lake waters from polluted tributaries like the Wulka river, we recommend diffuse pathways through the reed belt in the lake's littoral to reduce pollutant transport into the Lake and avoid high local sediment loadings. Second, water exchange with dried-up areas with probable higher loadings should be carefully handled and monitored to avoid critical back transport in the open lake. And third, general work in the reed belt or generally in the reed should be accompanied by monitoring to prevent uncontrolled remobilization in the future.

Automated Sampling Procedures Supported by High Persistence of Bacterial Fecal Indicators and Bacteroidetes Genetic Microbial Source Tracking Markers in Municipal Wastewater during Short-Term Storage at 5°C.

Because of high diurnal water quality fluctuations in raw municipal wastewater, the use of proportional autosampling over a period of 24 h at municipal wastewater treatment plants (WWTPs) to evaluate carbon, nitrogen, and phosphorus removal has become a standard in many countries. Microbial removal or load estimation at municipal WWTPs, however, is still based on manually recovered grab samples. The goal of this study was to establish basic knowledge regarding the persistence of standard bacterial fecal indicators and Bacteroidetes genetic microbial source tracking markers in municipal wastewater in order to evaluate their suitability for automated sampling, as the potential lack of persistence is the main argument against such procedures. Raw and secondary treated wastewater of municipal origin from representative and well-characterized biological WWTPs without disinfection (organic carbon and nutrient removal) was investigated in microcosm experiments at 5 and 21°C with a total storage time of 32 h (including a 24-h autosampling component and an 8-h postsampling phase). Vegetative Escherichia coli and enterococci, as well as Clostridium perfringens spores, were selected as indicators for cultivation-based standard enumeration. Molecular analysis focused on total (AllBac) and human-associated genetic Bacteroidetes (BacHum-UCD, HF183 TaqMan) markers by using quantitative PCR, as well as 16S rRNA gene-based next-generation sequencing. The microbial parameters showed high persistence in both raw and treated wastewater at 5°C under the storage conditions used. Surprisingly, and in contrast to results obtained with treated wastewater, persistence of the microbial markers in raw wastewater was also high at 21°C. On the basis of our results, 24-h autosampling procedures with 5°C storage conditions can be recommended for the investigation of fecal indicators or Bacteroidetes genetic markers at municipal WWTPs. Such autosampling procedures will contribute to better understanding and monitoring of municipal WWTPs as sources of fecal pollution in water resources.

A source-based framework to estimate the annual load of PFAS in municipal wastewater.

Per- and Polyfluoroalkyl substances (PFAS) are a class of persistent chemicals, whose impact has been observed in various environmental compartments. Wastewater treatment plants (WWTPs) are considered a major emission pathway of PFAS, specifically in the context of the aquatic environment. The goal of this study was to develop a compartmentalized, source-based load estimation model of 7 PFAS within the municipal wastewater influent. Consumer statistics, data from literature on PFAS concentrations and release during use, and specific sampling activities for environmental flows in the related city were used to estimate per capita emission loads. Model results were compared with loads obtained through the monitoring campaign at the municipal WWTP influent. A wide range of discrepancies (≈5 % to ≈90 %) between loads observed in the WWTP influent and source based model estimates was noticed. The loads less accounted by the model were associated with sulfonic acids (PFSAs), whereas for carboxylic acids (PFCAs) most of the observed loads could be reasonably explained by the model, with even an overestimation of nearly 5 % noted for PFNA. Higher heterogeneity in sources was observed in the PFCA group, with a noticeable dominance in the share of consumer products. PFSAs had less of a consumer product input (<20 %), with the rest of the modelled load being attributed to environmental inputs. A large gap of unknown loads of PFSAs indicates a need for examination of other, not yet quantified activities that can potentially explain the remainder of the observed load. Especially commercial activities are considered as potential additional sources for PFSAs. These findings signify the importance of PFAS that originate from both consumer products, as well as environmental inputs in the overall load contribution into the sewage, while identifying the need for further investigation into commercial sources of PFAS emitted into the municipal wastewater.

Advanced wastewater treatment with ozonation and granular activated carbon filtration: Inactivation of antibiotic resistance targets in a long-term pilot study.

The inactivation of antibiotic resistant bacteria (ARB) and genes (ARGs) in an advanced plant combining ozonation and granular activated carbon (GAC) filtration applied for effluent after conventional activated sludge treatment at a full-scale urban wastewater treatment plant was investigated for over 13 consecutive months. The nitrite compensated specific ozone dose ranged between 0.4 and 0.7 g O3/g DOC with short-time sampling campaigns (0.2-0.9 g O3/g DOC). Samples were analysed with culture-dependent methods for bacterial targets and with qPCR for genes. The log removal values were correlated with a decrease of the matrix UV absorption at 254 nm (ΔUV254) and indicated a range of ΔUV254 that corresponds to a sufficient membrane damage to affect DNA. For trimethoprim/sulfamethoxazole resistant E. coli, sul1, ermB and tetW, this phase was observed at ΔUV254 of ~30 % (~0.5 g O3/g DOC). For ampicillin resistant E. coli and blaTEM-1, it was observed around 35-40 % (~0.7 g O3/g DOC), which can be linked to mechanisms related to oxidative damages in bacteria resistant to bactericidal antibiotics. GAC treatment resulted in a further abatement for trimethoprim/sulfamethoxazole E. coli, sul1 and tetW, and in increase in absolute and relative abundance of ermB and blaTEM-1.

Intelligent monitoring networks--transformation of data into information for water management.

The EU-WFD requires certain monitoring tasks, which yet cannot be fulfilled by automated monitoring devices. Nevertheless, the technical progress of recent years allows monitoring station designs, which enable long-term field application under reasonable maintenance demand. State-of-the-art monitoring stations allow the setup and operation of intelligent monitoring networks, which deliver quality proved and utilisable information to the end-user as opposed to a collection of time-series. Based on a full-scale example monitoring station design, long-term observations and possible ways of (automated) data interpretation are discussed.

Benefits, limitations and uncertainty of in situ spectrometry.

In situ spectrometers are comparable robust instruments and can be operated long term with relatively low maintenance demand. The decisive factor for their applicability is the development of a medium and installation location specific correlation model, which estimates the concentration of the requested target parameter from the measured absorption values. In some cases it might turn out, that the development of a single site specific correlation model is not sufficient, due to frequent and substantial variations of the (waste) water composition.In order to assess the total uncertainty of in situ spectrometry, a comprehensive lab test was carried out. It includes a detailed investigation of the uncertainty of CODreference methods (DIN and small tube tests), a precision analysis of the absorption spectra and the impact of those two factors on the total uncertainty of the COD(EQ) correlation model.

Investigative monitoring in the context of detecting anthropogenic impact on an epipotamal river.

In the context of an investigative monitoring programme a monitoring system comprising of a water quality monitoring station and a camera station has been installed and operated for more than one year. The monitoring target was to investigate changes of water quality which can be related to a repeated occurrence of foam, observed at a river stretch downstream the monitoring station. The extent and frequency of foam buildup was recorded by means of the camera station. The analysis of the online data clearly showed that some of the measured parameters can be used as indicators for specific discharges, which from additional targeted investigations could be identified as contributors to the foaming problems. The continuous ammonium measurement could be used to detect nitrification problems of WWTPs discharging upstream of the monitoring station. By combining different data sources (emission data, operative and investigative monitoring data) additional information can be gained, which can be used for a comprehensive data assessment as well as a detailed system analysis.

Comparison of and uncertainties in raw sewage COD measurements by laboratory techniques and field UV-visible spectrometry.

A comprehensive investigation of the uncertainty of different COD analysis methods (DIN, small tube tests (STT) and UV-visible spectrometry methods) has been carried out on potassium hydrogen phthalate standard solutions and raw sewage samples from a large wastewater treatment plant. The UV-visible method allows estimating COD equivalent concentration from the measured absorption spectra by means of site specific regression and correlation functions. CODdin and CODstt methods showed equivalent global results but specific calibration relationships are necessary when high accuracy is required. The CODstt method is suitable for immediate COD analysis in the field. Sub-sampling is the main source of uncertainty. Spectrometry is able to estimate CODeq with an uncertainty of the same order of magnitude as the uncertainty in CODdin.

Application of ion-sensitive sensors in water quality monitoring.

Within the last years a trend towards in-situ monitoring can be observed, i.e. most new sensors for water quality monitoring are designed for direct installation in the medium, compact in size and use measurement principles which minimise maintenance demand. Ion-sensitive sensors (Ion-Sensitive-Electrode--ISE) are based on a well known measurement principle and recently some manufacturers have released probe types which are specially adapted for application in water quality monitoring. The function principle of ISE-sensors, their advantages, limitations and the different methods for sensor calibration are described. Experiences with ISE-sensors from applications in sewer networks, at different sampling points within wastewater treatment plants and for surface water monitoring are reported. An estimation of investment and operation costs in comparison to other sensor types is given.

In-situ measurement of ammonium and nitrate in the activated sludge process.

A new in-situ probe is presented for the continuous measurement of ammonium and nitrate in wastewater. It requires no sample preparation and is installed directly in the process liquid. This new low-cost probe significantly reduces investment and operating costs and requires minimum maintenance. The paper describes the sensor principle and test results from three different probe locations: the primary clarifier effluent, the activated sludge tank and the nitrifying biofilter influent. Reference measurements were carried out by means of conventional analyzers with ultrafiltration, an in-situ UV spectrometer for the nitrate and laboratory analysis of spot and 2h-composite samples. The aim of the study was to investigate the operational reliability and accuracy of the new probe and the expenditure required for its maintenance and calibration. The tests showed that the new probe performed very well overall and required minimum maintenance. Some problems were observed during the biofilter plant test. They are assumed to be related to substantial changes in the wastewater composition.

[Allergy skin-prick tests and standard inhalation of allergens in children up to 3 years of age]. / Alergoloski skin-prick test na standardne inhalacione alergene kod djece ispod tri godine.

There were 27 children tested on standard inhalation allergens. The number of children till one year old was 7, from one year till two years old were 8 children, and from two till three years of age were 12 children. Six children in the first group had a positive response to the histamine, only one child had a positive finding on house duct (urtica 5 mm, and histamine 2 mm). In the second group, from one till two years all children had histamine positive finding. Two children had positive finding on house dust, three of them had positive finding on dermatophagoides pteronisimus, while one child was positive on fungus. The remaining three children had regular finding. In the third group all children had positive finding on histamine, eight children were positive on house dust, three of them on dermatophagoides pteronisimus and one child on grass pollen. We think that the age of children is not a limit to application of allergy tests as a part of allergy examinations.

[Cat-scratch disease]. / Bolest macijeg ogreba.

We report a case of fourteen years old boy with cat scratch disease. He was treated at Pediatric Clinic in January and February 2000. Cat scratch disease is benign infectious chronic disease which appears in all ages. It begins after contact with cat and its scratch. Yearly incidence of this disease for whole population is 0.77-0.86/100.000. The cause is bacillus Bartonella which is also called genus Rochalimaea. It is Gram negative, mobile, aerobe bacillus with ten flagellas on one pole. Our patient was admitted at hospital because of high temperature, paleness, fatigue, bad appetite and pains in his joint. Ultrasound and magnet resonance scans of liver and spleen showed enlarged but regulary contured liver and two focal changes with diameter 16 mm, 12 mm and 7 mm in spleen. All those focal changes were described as abscesses. Diagnose was set up according increasing titre of IF-Bartonella hensalae IgG 1:256 (positive). This diagnostic test was performed at Institute for microbiology and Immunology at Medical Faculty in Ljubljana. Disease had long lasting course, and was cured by antibiotics without surgical intervention.

[Hypoparathyroidism]. / Hipoparatireoidizam.

Hypoparathyreoidism of different etiology is the most common disorder of parathyreoidea. Symptoms caused by hypocalcemia are dominant and they are sign of disturbed neuromuscular balance. Alopecia is frequent disorder which occurs in the course of the illness. We report a case of five year old girl sent from Mostar because seizures incurable by phenobarbitone. Total alopecia was obvious. At admission total serum calcium level was 1.23 mmol/l. The level of parathormon was measured two times, and both results were under lowest value of normal range (< 10 pg/ml). After introducing calcitriol (Rocaltrol) in therapy, serum calcium level was almost normal and child was without symptoms.