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Weyrauch P.,Kompetenzzentrum Wasser Berlin | Matzinger A.,Kompetenzzentrum Wasser Berlin | Pawlowsky-Reusing E.,Berliner Wasserbetriebe | Plume S.,Kompetenzzentrum Wasser Berlin | And 3 more authors.
Water Research | Year: 2010

The present study examines the contribution of combined sewer overflows (CSO) to loads and concentrations of trace contaminants in receiving surface water. A simple method to assess the ratio of CSO to wastewater treatment plant (WWTP) effluents was applied to the urban River Spree in Berlin, Germany. The assessment indicated that annual loads are dominated by CSO for substances with removal in WWTP above ∼95%. Moreover, it showed that substances with high removal in WWTP can lead to concentration peaks in the river during CSO events. The calculated results could be verified based on eight years of monitoring data from the River Spree, collected between 2000 and 2007. Substances that are well removed in WWTP such as NTA (nitrilotriacetic acid) were found to occur in significantly increased concentration during CSO, while the concentration of substances that are poorly removable in WWTP such as EDTA (ethylenediaminetetraacetic acid) decreased in CSO-influenced samples due to dilution effects. The overall results indicate the potential importance of the CSO pathway of well-removable sewage-based trace contaminants to rivers. In particular, high concentrations during CSO events may be relevant for aquatic organisms. Given the results, it is suggested to include well-removable, sewage-based trace contaminants, a substance group often neglected in the past, in future studies on urban rivers in case of combined sewer systems. The presented methodology is suggested for a first assessment, since it is based solely on urban drainage data, which is available in most cities. © 2010 Elsevier Ltd.

Fenu A.,Aquafin NV | Guglielmi G.,University of Trento | Guglielmi G.,E.T.C. Engineering srl | Jimenez J.,Veolia | And 6 more authors.
Water Research | Year: 2010

Membrane bioreactors (MBRs) have been increasingly employed for municipal and industrial wastewater treatment in the last decade. The efforts for modelling of such wastewater treatment systems have always targeted either the biological processes (treatment quality target) as well as the various aspects of engineering (cost effective design and operation). The development of Activated Sludge Models (ASM) was an important evolution in the modelling of Conventional Activated Sludge (CAS) processes and their use is now very well established. However, although they were initially developed to describe CAS processes, they have simply been transferred and applied to MBR processes. Recent studies on MBR biological processes have reported several crucial specificities: medium to very high sludge retention times, high mixed liquor concentration, accumulation of soluble microbial products (SMP) rejected by the membrane filtration step, and high aeration rates for scouring purposes. These aspects raise the question as to what extent the ASM framework is applicable to MBR processes. Several studies highlighting some of the aforementioned issues are scattered through the literature. Hence, through a concise and structured overview of the past developments and current state-of-the-art in biological modelling of MBR, this review explores ASM-based modelling applied to MBR processes. The work aims to synthesize previous studies and differentiates between unmodified and modified applications of ASM to MBR. Particular emphasis is placed on influent fractionation, biokinetics, and soluble microbial products (SMPs)/exo-polymeric substances (EPS) modelling, and suggestions are put forward as to good modelling practice with regard to MBR modelling both for end-users and academia. A last section highlights shortcomings and future needs for improved biological modelling of MBR processes. © 2010 Elsevier Ltd.

Riechel M.,Kompetenzzentrum Wasser Berlin | Matzinger A.,Kompetenzzentrum Wasser Berlin | Pawlowsky-Reusing E.,Berliner Wasserbetriebe | Sonnenberg H.,Kompetenzzentrum Wasser Berlin | And 5 more authors.
Water Research | Year: 2016

To support decision makers in planning effective combined sewer overflow (CSO) management strategies an integrated modelling and impact assessment approach has been developed and applied for a large urban area in Berlin, Germany. It consists of an urban drainage model, a river water quality model and a tool for the quantification of adverse dissolved oxygen (DO) conditions in the river, one of the main stressors for urban lowland rivers. The coupled model was calibrated successfully with average Nash-Sutcliffe-efficiencies for DO in the river of 0.61 and 0.70 for two validation years. Moreover, the whole range of observed DO concentrations after CSO down to 0 mg L−1 is simulated by the model. A local sensitivity analysis revealed that in the absence of CSO dissolved oxygen principally depends on phytoplankton dynamics. Regarding CSO impacts, it was shown that 97% of the observed DO deficit can be explained by the three processes (i) mixing of river water with CSO spill water poor in DO, (ii) reduced phytoplankton activity due to CSO-induced turbidity and (iii) degradation of organic matter by heterotrophic bacteria. As expected, process (iii) turned out to be the most important one. However depending on the time lag after CSO the other processes can become dominant. Given the different involved processes, we found that different mitigation schemes tested in a scenario analysis can reduce the occurrence of critical DO deficits in the river by 30–70%. Overall, the study demonstrates that integrated sewer-river-models can be set up to represent CSO impacts under complex urban conditions. However, a significant effort in monitoring and modelling is a requisite for achieving reliable results. © 2016 Elsevier Ltd

PubMed | Wurttembergische Strasse, Berliner Wasserbetriebe and Kompetenzzentrum Wasser Berlin
Type: | Journal: Water research | Year: 2016

To support decision makers in planning effective combined sewer overflow (CSO) management strategies an integrated modelling and impact assessment approach has been developed and applied for a large urban area in Berlin, Germany. It consists of an urban drainage model, a river water quality model and a tool for the quantification of adverse dissolved oxygen (DO) conditions in the river, one of the main stressors for urban lowland rivers. The coupled model was calibrated successfully with average Nash-Sutcliffe-efficiencies for DO in the river of 0.61 and 0.70 for two validation years. Moreover, the whole range of observed DO concentrations after CSO down to 0mgL

Genz C.,TU Berlin | Miehe U.,KompetenzZentrum Wasser Berlin | Gnirss R.,Berliner Wasserbetriebe | Jekel M.,TU Berlin
Water Science and Technology | Year: 2011

The impact of a pre-treatment by pre-ozonation (2-10 mg O 3/L) and subsequent coagulation (FeCl 3: 2-6 mg Fe 3+/L) on the performance of a polymeric ultrafiltration membrane was investigated in lab scale. The performance was assessed by monitoring the flux decline during filtration of secondary effluent in Amicon test cells. During the filtration process no free dissolved ozone was in contact with the membrane. It was observed that flux decline is reduced with increasing coagulant concentration as well as with increasing ozone dosage. This effect involves a reduction in the amount of biopolymers measured by size exclusion chromatography (LC-OCD). Moreover, multi-filtration cycles revealed that pre-ozonation leads to a significant increase in irreversible fouling that might be caused by increasing colloidal iron concentrations. Phosphorus in the permeate was successfully reduced to concentrations <60 μg/L. © IWA Publishing 2011.

Litz N.T.,Federal Environmental Agency UBA | Weigert A.,TU Dresden | Krause B.,Federal Environmental Agency UBA | Heise S.,Federal Environmental Agency UBA | Grutzmacher G.,KompetenzZentrum Wasser Berlin
Water Research | Year: 2011

The herbicide Glyphosate was detected in River Havel (Berlin, Germany) in concentrations between 0.1 and 2 μg/L (single maximum outlier: 5 μg/L). As the river indirectly acts as drinking water source for the city's 3.4 Mio inhabitants potential risks for drinking water production needed to be assessed. For this reason laboratory (sorption and degradation studies) and technical scale investigations (bank filtration and slow sand filter experiments) were carried out. Batch adsorption experiments with Glyphosate yielded a low KF of 1.89 (1/n = 0.48) for concentrations between 0.1 and 100 mg/L. Degradation experiments at 8 °C with oxygen limitation resulted in a decrease of Glyphosate concentrations in the liquid phase probably due to slow adsorption (half life: 30 days).During technical scale slow sand filter (SSF) experiments Glyphosate attenuation was 70-80% for constant inlet concentrations of 0.7, 3.5 and 11.6 μg/L, respectively. Relevant retardation of Glyphosate breakthrough was observed despite the low adsorption potential of the sandy filter substrate and the relatively high flow velocity. The VisualCXTFit model was applied with data from typical Berlin bank filtration sites to extrapolate the results to a realistic field setting and yielded sufficient attenuation within a few days of travel time. Experiments on an SSF planted with Phragmites australis and an unplanted SSF with mainly vertical flow conditions to which Glyphosate was continuously dosed showed that in the planted SSF Glyphosate retardation exceeds 54% compared to 14% retardation in the unplanted SSF. The results show that saturated subsurface passage has the potential to efficiently attenuate glyphosate, favorably with aerobic conditions, long travel times and the presence of planted riparian boundary buffer strips. © 2011 Elsevier Ltd.

Schroeder K.,Kompetenzzentrum Wasser Berlin | Riechel M.,Kompetenzzentrum Wasser Berlin | Matzinger A.,Kompetenzzentrum Wasser Berlin | Rouault P.,Kompetenzzentrum Wasser Berlin | And 3 more authors.
Water Science and Technology | Year: 2011

The effect of combined sewer overflow (CSO) control measures should be validated during operation based on monitoring of CSO activity and subsequent comparison with (legal) requirements. However, most CSO monitoring programs have been started only recently and therefore no long-term data is available for reliable efficiency control. A method is proposed that focuses on rainfall data for evaluating the effectiveness of CSO control measures. It is applicable if a sufficient time-series of rainfall data and a limited set of data on CSO discharges are available. The method is demonstrated for four catchments of the Berlin combined sewer system. The analysis of the 2000-2007 data shows the effect of CSO control measures, such as activation of in-pipe storage capacities within the Berlin system. The catchment, where measures are fully implemented shows less than 40% of the CSO activity of those catchments, where measures have not yet or not yet completely been realised. © IWA Publishing 2011.

Muller B.,TU Berlin | Scheytt T.,TU Berlin | Grutzmacher G.,Kompetenzzentrum Wasser Berlin
Journal of Soils and Sediments | Year: 2013

Purpose: The transport behavior of human pharmaceuticals in groundwater depends on a multitude of factors such as the physico-chemical conditions in the aquifer and the organic carbon content of the sediment, and, in particular, on the redox conditions in the groundwater. This is of special interest at managed aquifer recharge sites where the occurrence of trace organics is important for drinking water production. The aim of this study was to evaluate the possibility of influencing the redox system of the aquifer in a way that optimizes the potential of managed aquifer recharge systems to reduce the amount of trace organics. Materials and methods: Column studies were performed using natural and thermally treated sediments from an infiltration basin of the Berlin area, Germany. Special emphasis was placed on thermal treatment of the sediments to influence the total organic carbon (TOC) content in the sediment. In one experiment, the sediment was thermally pretreated at 550 °C, in two experiments the sediment was pretreated at 200 °C, and in one the sediment was untreated. Furthermore, the influence of ozonation, a very common disinfectant used in drinking water production, was studied in the experiments. The retardation and degradation parameters for primidone (PMD), carbamazepine (CBZ), and sulfamethoxazole (SMX) under different redox conditions were evaluated. Results and discussion: Oxic conditions were obtained in the experiment with low TOC (0. 06 wt%) in the sediment pre-treated at 550 °C. Anoxic conditions were predominant in two column experiments with a TOC content of 0. 17 wt% in the sediment, irrespective of the mode of treatment (natural or 200 °C). All three pharmaceutical compounds show almost conservative transport behavior with retardation factors between 1. 02 and 1. 25 for PMD, between 1. 06 and 1. 37 for CBZ, and between 1. 00 and 1. 08 for SMX. Differences in the transport behavior were observed depending on the TOC content of the sediment. For CBZ, and to a minor extent for PMD, the higher retardation factors were observed in the sediment with a TOC content of 0. 17 wt% under anoxic conditions. The ozonation of the influent water affects the influent concentrations of PMD, CBZ and SMX. However, it has no influence on the oxygen concentration of the column outflow. Conclusions: CBZ and PMD are retarded in the presence of organic matter in the aquifer. Variations of the TOC content of the sediment have a direct influence on the retardation of CBZ and PMD. The three human pharmaceuticals may be ranked in order of decreasing retardation: CBZ & PMD & SMX. The microbial activity in the experiments was not studied, although it can be assumed that the thermal pretreatment influences the microbial activity in the sediments. In particular, the microbial activity was severely inhibited at 550 °C, resulting in a shift of the redox conditions. © 2013 Springer-Verlag Berlin Heidelberg.

Escaler I.,aqua Water Technology Center | Cabello A.,aqua Water Technology Center | Campos C.,Sociedad General de Aguas de Barcelona | Lesjean B.,KompetenzZentrum Wasser Berlin | And 2 more authors.
Journal of Water and Climate Change | Year: 2012

The Water supply and sanitation Technology Platform (WssTP) was initiated by the European Commission in 2004. It is led by industries in collaboration with academics, research organisations and water users to help structure the European Research Area and identify R&D needs for the water sector. In December 2008, the board of the WssTP identified the need to create a Task Force on Climate Change in order to build a working group focused on the issue and able to assist the EU Commission in the related Calls for Projects. The Task Force on Climate Change did a review on the research and technology development (RTD) needs related to each of the WssTP topics, highlighting the challenges they will face in a climate change context. This paper is based on the review carried out and presents its main conclusions. The RTD topics identified involve a broad range of expertise areas and can be divided into two main groups: mitigation and adaptation. The latter will be brought to the fore in this paper. © WSSTP 2012 Journal of Water and Climate Change.

Staub M.J.,Kompetenzzentrum Wasser Berlin | Staub M.J.,Joseph Fourier University | Staub M.J.,Veolia | Gourc J.-P.,Joseph Fourier University | And 3 more authors.
Journal of Hazardous, Toxic, and Radioactive Waste | Year: 2013

Municipal solid waste (MSW) in landfill bioreactors is subjected to mechanical, biological, and hydrological processes. To understand these processes, four large-scale bioreactor pilots were specifically designed to simulate the behavior of waste in the core of a landfill. Here, the results of two long-term tests that were performed in two compression cells are presented. Mechanical, biochemical, and hydrological parameters were analyzed throughout the experiments. The promising results of this research improve the understanding of biodegradation and its correlation with the hydromechanical behavior of municipal solid waste. In particular, the sensitivity of the biodegradation to leachate injection and the correlation between the biogas flow and vertical settlement were confirmed for wastes with high initial moisture content. The results showed that it is important to consider the potential of different monitoring techniques and the representative volume for the experimental approach. Furthermore, the operational results led to interesting conclusions, especially regarding the addition of moisture to waste, which is a key element for bioreactor landfill operation. © 2013 American Society of Civil Engineers.

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