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Biesheuvel P.M.,Wageningen University | Biesheuvel P.M.,Center of Excellence for Sustainable Water Technology
Journal of Colloid and Interface Science | Year: 2011

To describe the velocities of particles such as ions, protein molecules and colloids dispersed or dissolved in a fluid, it is important to also describe the forces acting on the fluid, including pressure gradients and friction of the fluid with the particles and with the porous media through which the fluid flows. To account for this problem, the use of a two-fluid model is described, familiar in the field of fluid mechanics, extended to include osmotic effects. We show how familiar relationships follow in various situations and give examples of combined fluid/particle transport in neutral and charged membranes driven by a combination of electrostatic, diffusional and pressure forces. The analysis shows how the same modeling framework can be generally used both for multidimensional electrokinetic flow through macroscopic channels and around macroscopic objects, as well as for mean-field modeling of transport through porous media such as gels and membranes. © 2010 Elsevier Inc. Source

Daniilidis A.,University of Groningen | Herber R.,University of Groningen | Vermaas D.A.,Center of Excellence for Sustainable Water Technology | Vermaas D.A.,University of Twente
Applied Energy | Year: 2014

Energy can be produced from mixing waters with different salinity in reverse electrodialysis (RED). Technological improvements make RED gaining momentum as a technically viable option for baseload renewable energy generation. In this paper a model is presented for three different RED applications in terms of upscale potential based on experimental data in the probabilistic software GoldSim. For a project life of 30years (including a 5year pilot phase), the economics and avoided CO2 emissions of such a power plant for three different price scenarios and three different feed solutions are examined. Subsequently an evaluation is carried out of the upscale potential, the economic break-even membrane price of a large scale RED power plant is quantified, identifying the most influential inputs through a sensitivity analysis. Furthermore, future performance and price developments are incorporated in the model and a comparison is made of a RED power plant with other conventional and renewable energy sources in terms of the Levelised Cost Of Electricity (LCOE) index. Brine applications seem to be closer to economic viability with the present state of technology and an optimistic membrane pricing scenario, but can only be upscaled to the order of 1MW. River and seawater are not yet economically attractive but have an upscale potential close to 290MW for the Dutch context. However, considering future development in membrane performance and price, the LCOE for electricity generation with river and seawater using RED is competitive to other renewable energy sources such as biomass and wind. © 2014 Elsevier Ltd. Source

Dopson M.,Linnaeus University | Ni G.,Linnaeus University | Sleutels T.H.J.A.,Center of Excellence for Sustainable Water Technology
FEMS Microbiology Reviews | Year: 2016

Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems. © FEMS 2015. Source

Agency: Cordis | Branch: H2020 | Program: MSCA-COFUND-DP | Phase: MSCA-COFUND-2014-DP | Award Amount: 6.67M | Year: 2016

The objective of the WaterSEED project is to provide a doctoral program to excellent early stage researchers (ESRs) that want to develop their skills and contribute to the development of breakthrough technologies for water related challenges. Key elements in the program are the strong focus on interdisciplinary interaction, entrepreneurial skills and societal relevance. The project will use the existing Wetsus doctoral (PhD) program as a strong base and will enable this program to become even more international and relevant for the European society. The Wetsus doctoral program has grown in the 10 years of its existence to a prime example of smart, regional specialization on water technology with a strong European connection between research institutes and industry partners. The research in the Wetsus program takes place in close collaboration with 90 companies that actively participate in the research through paying memberships to focused and high trust research themes. All Wetsus researchers have at least three contacts per year with these industry partners. The current doctoral program has a strong regional and national funding base. Through COFUND this program will be further expanded and strengthened by attracting 45 international, excellent young researchers to the program in the period of 2015-2020. It will also strengthen the European connection of the program by increasing the number of researchers from other countries than the host organisation to over 70%. The ESRs will be selected in two calls per year through a transparent and thorough selection process, including a two day WaterSEED Recruitment Challenge at Wetsus for the best candidates.

Biesheuvel P.M.,Wageningen University | Biesheuvel P.M.,Center of Excellence for Sustainable Water Technology | Bazant M.Z.,Massachusetts Institute of Technology
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) valid in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory for the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) in the "supercapacitor regime" of small voltages and/or early times, the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore, and (ii) in the "desalination regime" of large voltages and long times, the porous electrode slowly absorbs counterions, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration. © 2010 The American Physical Society. Source

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