Vonberg D.,Jülich Research Center |
Vanderborght J.,Jülich Research Center |
Cremer N.,Erftverband |
Putz T.,Jülich Research Center |
And 2 more authors.
Water Research | Year: 2014
Atrazine was banned in Germany in 1991 due to findings of atrazine concentrations in ground- and drinking waters exceeding threshold values. Monitoring of atrazine concentrations in the groundwater since then provides information about the resilience of the groundwater quality to changing agricultural practices. In this study, we present results of a monitoring campaign of atrazine concentrations in the Zwischenscholle aquifer. This phreatic aquifer is exposed to intensive agricultural land use and susceptible to contaminants due to a shallow water table. In total 60 observation wells (OWs) have been monitored since 1991, of which 15 are sampled monthly today. Descriptive statistics of monitoring data were derived using the "regression on order statistics" (ROS) data censoring approach, estimating values for nondetects. The monitoring data shows that even 20 years after the ban of atrazine, the groundwater concentrations of sampled OWs remain on a level close to the threshold value of 0.1μgl-1 without any considerable decrease. The spatial distribution of atrazine concentrations is highly heterogeneous with OWs exhibiting permanently concentrations above the regulatory threshold on the one hand and OWs were concentrations are mostly below the limit of quantification (LOQ) on the other hand. A deethylatrazine-to-atrazine ratio (DAR) was used to distinguish between diffuse - and point-source contamination, with a global mean value of 0.84 indicating mainly diffuse contamination. Principle Component Analysis (PCA) of the monitoring dataset demonstrated relationships between the metabolite desisopropylatrazine, which was found to be exclusively associated with the parent compound simazine but not with atrazine, and between deethylatrazine, atrazine, nitrate, and the specific electrical conductivity. These parameters indicate agricultural impacts on groundwater quality.The findings presented in this study point at the difficulty to estimate mean concentrations of contamination for entire aquifers and to evaluate groundwater quality based on average parameters. However, analytical data of monthly sampled single observation wells provide adequate information to characterize local contamination and evolutionary trends of pollutant concentration. © 2013 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.
Agency: European Commission | Branch: H2020 | Program: IA | Phase: WATER-1b-2015 | Award Amount: 10.74M | Year: 2016
The AquaNES project will catalyse innovations in water and wastewater treatment processes and management through improved combinations of natural and engineered components. Among the demonstrated solutions are natural treatment processes such as bank filtration (BF), managed aquifer recharge (MAR) and constructed wetlands (CW) plus engineered pre- and post-treatment options. The project focuses on 13 demonstration sites in Europe, India and Israel covering a repre-sentative range of regional, climatic, and hydrogeological conditions in which different combined natural-engineered treatment systems (cNES) will be demonstrated through active collaboration of knowledge and technology providers, water utilities and end-users. Our specific objectives are to demonstrate the benefits of post-treatment options such as membranes, activated carbon and ozonation after bank filtration for the production of safe drinking water to validate the treatment and storage capacity of soil-aquifer systems in combination with oxidative pre-treatments to demonstrate the combination of constructed wetlands with different technical post- or pre-treatment options (ozone or bioreactor systems) as a wastewater treatment option to evidence reductions in operating costs and energy consumption to test a robust risk assessment framework for cNES to deliver design guidance for cNES informed by industrial or near-industrial scale expe-riences to identify and profile new market opportunities in Europe and overseas for cNES The AquaNES project will demonstrate combined natural-engineered treatment systems as sus-tainable adaptations to issues such as water scarcity, excess water in cities and micro-pollutants in the water cycle. It will thus have impact across the EIP Waters thematic priorities and cross-cutting issues, particularly on Water reuse & recycling, Water and wastewater treatment, Water-energy nexus, Ecosystem services, Water governance, and DSS & monitoring.
Verrecht B.,Cranfield University |
Maere T.,Ghent University |
Nopens I.,Ghent University |
Brepols C.,Erftverband |
Judd S.,Cranfield University
Water Research | Year: 2010
A cost sensitivity analysis was carried out for a full-scale hollow fibre membrane bioreactor to quantify the effect of design choices and operational parameters on cost. Different options were subjected to a long term dynamic influent profile and evaluated using ASM1 for effluent quality, aeration requirements and sludge production. The results were used to calculate a net present value (NPV), incorporating both capital expenditure (capex), based on costs obtained from equipment manufacturers and full-scale plants, and operating expenditure (opex), accounting for energy demand, sludge production and chemical cleaning costs.Results show that the amount of contingency built in to cope with changes in feedwater flow has a large impact on NPV. Deviation from a constant daily flow increases NPV as mean plant utilisation decreases. Conversely, adding a buffer tank reduces NPV, since less membrane surface is required when average plant utilisation increases. Membrane cost and lifetime is decisive in determining NPV: an increased membrane replacement interval from 5 to 10 years reduces NPV by 19%. Operation at higher SRT increases the NPV, since the reduced costs for sludge treatment are offset by correspondingly higher aeration costs at higher MLSS levels, though the analysis is very sensitive to sludge treatment costs. A higher sustainable flux demands greater membrane aeration, but the subsequent opex increase is offset by the reduced membrane area and the corresponding lower capex. © 2010 Elsevier Ltd.
Brepols Ch.,Erftverband |
Schafer H.,Erftverband |
Water Science and Technology | Year: 2010
Based on the practical experience in design and operation of three full-scale membrane bioreactors (MBR) for municipal wastewater treatment that were commissioned since 1999, an overview on the different design concepts that were applied to the three MBR plants is given. The investment costs and the energy consumption of the MBRs and conventional activated sludge (CAS) plants (with and without tertiary treatment) in the Erft river region are compared. It is found that the specific investment costs of the MBR plants are lower than those of comparable CAS with tertiary treatment. A comparison of the specific energy demand of MBRs and conventional WWTPs is given. The structure of the MBRs actual operational costs is analysed. It can be seen that energy consumption is only responsible for one quarter to one third of all operational expenses. Based on a rough design and empirical cost data, a cost comparison of a full-scale MBR and a CAS is carried out. In this example the CAS employs a sand filtration and a disinfection in order to achieve comparable effluent quality. The influence of membrane lifetime on life cycle cost is assessed. © IWA Publishing 2010.
Christoffels E.,Erftverband |
WIT Transactions on Ecology and the Environment | Year: 2014
A study has been conducted on a retention soil filter (RSF) to test its effectiveness in removing pharmaceutical residues from combined sewer overflows (CSO). Efficient removal of solids, nutrients and heavy metals has already been proven by Frechen (Neue Erkenntnisse zur Mischwasserbehandlung in Retentionsbodenfiltern, 2012). The possibility that organic micropollutants are also retained by the use of retention soil filters has been identified, but data is lacking. Results obtained in this study, in which testing for removal by RSF of numerous micropollutant substances has been performed, are most promising. The pharmaceuticals diclofenac and ibuprofen are presented in detail as examples of such micropollutants. Both show a reduction in positive samples of more than 55% as well as a significant reduction in median and maximum concentrations. These results add to the evidence that using retention soil filters in the advanced treatment of wastewater from combined sewer overflows reduces the exposure of watercourses to pharmaceutical residues. © 2014 WIT Press.
WIT Transactions on Ecology and the Environment | Year: 2014
Monitoring activities for detecting micropollutant concentration ranges have been developed for the Swist river in the German state of North Rhine- Westphalia. The monitoring program covers various point and non-point emission input sources as well as immissions in the watercourse and takes regional factors such as climate, land use and population density into consideration. Data for a relatively large number (up to 160) and broad range of anthropogenic micropollutants (e.g. pharmaceuticals, pesticides and industrial chemicals) has been gathered and analysed. Substance loads at wastewater treatment plant outlets as well as within the river are calculated from flow data and substance concentrations. Sampling times are defined according to season and weather conditions. Knowledge has been gained regarding temporal and spatial variation in the appearance of micropollutants and the requirements for a monitoring program to cover these fluctuations. Moreover, experience has been gained in mass flow analysis and emission balancing. © 2014 WIT Press.
WIT Transactions on Ecology and the Environment | Year: 2012
The DWA water quality model can be used for a wide range of water management planning activities. Fields of application extend from data and system analysis, to the analysis of alternatives in water pollution control planning, to the implementation of alarm plans. The example of the Erft river is used to present the results of water quality simulations with a view to assessing current conditions and forecasting the future development of water quality. © 201 WIT Press.
WIT Transactions on Ecology and the Environment | Year: 2013
A clear picture of the dynamic processes of river water quality, in particular for a river such as the Erft with low mean water flow combined with intensive water use, cannot be obtained through simple spot checks. For this reason, twenty-three years ago the Erftverband, a water management association in North Rhine-Westphalia (Germany), initiated an online monitoring network consisting of six water quality monitoring stations for continuous recording of contents of surface water in the Erft catchment. Measurement data combined with physicochemical and biological data from routine spot checks is processed at a central facility to yield information needed to assess and if necessary to improve water quality. Examples of such information are presented. The considerable advantages for river basin management planning are disclosed. © 2013 WIT Press.
PubMed | Erftverband
Type: Journal Article | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2016
Micropollutant pathways were studied for the Swist river basin (Western Germany). The aim was to verify the effectiveness of a monitoring approach to detect micropollutants entering the river. In a separate sewer system, water was frequently found to be contaminated with micropollutants. Improper connections of sewage canals to the stormwater network seemed to be the cause of pollution. Wastewater treatment plants (WWTPs) exerted the largest influence on micropollutants for the receiving river. During a flu outbreak, antibiotics in the Swist stemming from WWTPs increased remarkably. Elevated levels of pharmaceuticals were measured in discharges from a combined sewer overflow (CSO). The study showed that the pharmaceutical load of a CSO was significantly reduced by advanced treatment with a retention soil filter. Painkillers, an anticonvulsant and beta blockers were the most often detected pharmaceuticals in the sewage of urban areas. Herbicides, flame retardants and industrial compounds were also observed frequently. On cropland, Chloridazon and Terbuthylazine compounds were often found in landscape runoff. Fungicides and insecticides were the most frequent positive findings in runoff from orchards. The paper shows that a coherent approach to collecting valid information regarding micropollutants and to addressing relevant pathways as a basis for appropriate management strategies could be established.