Mari Winkler wint Jaap van der Graaf Prijs 2011 voor beste wetenschappelijk artikel in een internationaal tijdschrift. Gefeliciteerd, Mari! #yam

dr.ir. Marthe de Graaff MSc, PhD, scientific researcher, bij KWRWatercycle Research Institute greep vanmiddag - helaas - naast de Jaap van der Graaf Prijs voor beste paper 2011 tijdens de Vakantiecursus van de Faculteit CITG aan de TU Delft. Hieronder een abstract van haar artikel en een aantal illustraties.
 
M.S. de Graaff, H. Temmink, G. Zeeman, M.C.M. van Loosdrecht, C.J.N. Buisman, 'Autotrophic nitrogen removal from black water: Calcium addition as a requirement for settleability. In: Water Research 45 (2011) 63-74

Abstract
Black (toilet) water contains half of the organic load in the domestic wastewater, as well as the major fraction of the nutrients nitrogen and phosphorus. When collected with vacuum toilets, the black water is 25 times more concentrated than the total domestic wastewater stream, i.e. including grey water produced by laundry, showers etc. A two-stage nitritationeanammox process was successfully employed and removed 85%e89% of total nitrogen in anaerobically treated black water. The (free) calcium concentration in black water was too low (42 mg/L) to obtain sufficient granulation of anammox biomass. The granulation and retention of the biomass was improved considerably by the addition of 39 mg/L of extra calcium. This resulted in a volumetric nitrogen removal rate of 0.5 gN/L/d, irrespective of the two temperatures of 35 C and 25 C at which the anammox reactors were operated. Nitrous oxide, a very strong global warming gas, was produced in situations of an incomplete anammox conversion accompanied by elevated levels of nitrite.

 

Outlook

Treatment concept for black water: combined anaerobic treatment and nitrogen removal.

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Pictures of the granules in anammox SBR35 taken at day 140 (left) and day 341 (right).

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SEM observations of SBR35 granules (on the left granules in the reactor at day 204 without additional calcium and on the right granules in the reactor at day 348 with additional calcium).

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FISH pictures (left (red) AMX368, middle (green) EUBmix and right (blue) DAPI); A: SBR35 on day 153; B: SBR25 on day 181.

published peer reviewed: Simulating Nonresidential Water Demand with a Stochastic End-Use Model #yam

E.J.M. Blokker, E.J. Pieterse-Quirijns, J.H.G. Vreeburg, and J.C. van Dijk recently published ‘Simulating Nonresidential Water Demand with a Stochastic End-Use Model’ in: Journal of Water Resources Planning and Management 137 (2011)6, p.511-520.

           

Abstract

The end-use model SIMDEUM for residential water demand has been extended to incorporate nonresidential water demand. The model was developed to predict water-demand patterns with a small timescale (1 s) and small spatial scale (at the water meter connection). The end-use model is based on statistical information about users and end uses: data on occupancy; the frequency of use; duration and flow per water-use event; and the occurrence over the day of different end uses, such as flushing the toilet, doing the laundry, and washing hands. The model follows a modular approach, in that each type of building is composed of functional rooms, such as lodgings, restaurants, and conference rooms. A functional room is characterized by its typical users and water-using appliances. With this approach, nonresidential buildings’ water-demand patterns over the day can be simulated. The simulation results for an office building, a hotel, and a nursing home were compared to measured water-demand patterns with regard to attributes such as peak flow and daily total water use, as well as the shape of the pattern. The simulation results show a good correspondence to measured water demands. The end-use model is based on independent statistical information and not on flow measurements. The input parameters are available before any information on annual or daily water use is available; the parameters are not fitted on flow measurements. Therefore, the model is transferable to a diverse range of nonresidential water-demand types. The model can be applied in the design stage (prebuild), in scenario studies, and in distribution network models. More >>

You will find more peer reviewed articles on 'KWR Publications'

published peer reviewed: Effect of draw solution type and operational mode of forward osmosis with laboratory-scale membranes and a spiral wound membrane module #yam

E.R. Cornelissen, D.J.H. Harmsen, E.F. Beerendonk, J.J. Qin and J.W.M.N. Kappelhof recently published ‘Effect of draw solution type and operational mode of forward osmosis with laboratory-scale membranes and a spiral wound membrane module.’ in: Journal of Water Reuse and Desalination 1 (2011)3, p.133-140.

           

Abstract

Forward osmosis (FO) is a concentration driven membrane process which recently gained an increase in attention due to the development of improved FO membranes. Most of the currently available data on FO research is obtained on small laboratory-scale set-ups, thereby overlooking the effects of scaling-up to pilot or full-scale size. In this paper, FO experiments are carried out with a 10.16 cm (4-in) spiral wound FO (SWFO) Hydration Technologies Innovations (HTI) module. The performance of the SWFO module was investigated during daily experiments and the influence of two types of draw solutions (NaCl and MgCl2) was evaluated and compared to data from lab-scale FO research. Furthermore, the difference between fixed draw solution concentration and draw solution dilution was studied for both draw solutions. Salt flux was determined from the increase in: (i) conductivity; and (ii) individual ion concentration in the feed vessel. Water and salt flux values from laboratory-scale membrane FO experiments were similar but slightly lower than that of the SWFO module in the fixed draw solution concentration experiments (respectively 5 L/m2h and 3 g/m2h for 0.5 M NaCl). Salt flux values obtained from individual ion measurements were lower and more accurate compared to that determined by conductivity measurements. More >>

 

You will find more peer reviewed articles on 'KWR Publications'

publiceerde recentelijk in H2O: De drinkwatervoorziening in Nederland in 2040 #yam

Click here to download:
buscher.pdf (1.84 MB)

Wuijts, S., Verweij, W., de Roda Husman, A.M., BĆ¼scher, C. (2011) publiceerden recentelijk: 'De drinkwatervoorziening in Nederland in 2040' in H2O, 44 (25/26):4-5.
 

Hoe ziet de drinkwatervoorziening in Nederland er uit in 2040? Het RIVM heeft in samenwerking met KWR voor het ministerie van Infrastructuur en Milieu een toekomstverkenning uitgevoerd naar de drinkwatervoorziening in Nederland in 2040. De verkenning geeft ontwikkelingen aan in de drinkwatervraag en de kwaliteit van bronnen voor drinkwater en is gemaakt als voorbereiding voor de nog op te stellen Nota Drinkwater van dit ministerie. Dit gebeurt naar aanleidig van de Drinkwaterwet die sinds juli jl. van kracht is.

 

Om een beeld te krijgen van Nederland in 2040 en met welke ontwikkelingen voor de drinkwatervoorziening rekening zou moeten worden gehouden, is in deze studie gewerkt met toekomstscenario's. Hiervoor is gebruik gemaakt van al beschikbare scenario's voor de welvaart en leefomgeving en voor het klimaat. Deze scenario's zijn verder uitgewerkt voor de ontwikkeling van de drinkwatervraag en de beschikbaarheid en kwaliteit van bronnen in 2040.

published: Fixture-level demand modelling for improved network knowledge #yam

Blokker, E.J.M. recently published 'Fixture-level demand modelling for improved network knowledge' in: Water21 (2011), december, p.36-37.

Abstract:
A new end-use hydraulic model for water supply networks, SIMDEUM, has been developed to better understand parameters that affect water quality through modelling water demand at a fixture level. Mirjam Blokker discusses the need for such a model, and how using water use data can allow for improved prediction of water quality in the network.

You will find more peer reviewed articles on 'KWR Publications'

 

published peer reviewed: Going beyong limitations of plant fuctional types when predicting global ecosystem-atmosphere fluxes #yam

P.M. Van Bodegom, J.C. Douma, J.P.M. Witte, J.C. OrdoƱez, R. P. Bartholomeus and R. Aerts recently published 'Going beyong limitations of plant fuctional types when predicting global ecosystem-atmosphere fluxes: exploring the merits of traits-based approaches' in: Ecology and Biogeography (2011) DOI: 10.1111/j.1466-8238.2011.00717x

           

Abstract

Aim - Despite their importance for predicting fluxes to and from terrestrial ecosystems, dynamic global vegetation models have insufficient realism because of their use of plant functional types (PFTs) with constant attributes. Based on recent advances in community ecology, we explore the merits of a traits-based vegetation model to deal with current shortcomings.

Location - Global.

Methods - A research review of current concepts and information, providing a new perspective, supported by quantitative analysis of a global traits database.

Results - Continuous and process-based traitĀ–environment relations are central to a traits-based approach and allow us to directly calculate fluxes based on functional characteristics. By quantifying community assembly concepts, it is possible to predict trait values from environmental drivers, although these relations are still imperfect. Through the quantification of these relations, effects of adaptation and species replacement upon environmental changes are implicitly accounted for. Such functional links also allow direct calculation of fluxes, including those related to feedbacks through the nitrogen and water cycle. Finally, a traits-based model allows the prediction of new trait combinations and no-analogue ecosystem functions projected to arise in the near future, which is not feasible in current vegetation models. A separate calculation of ecosystem fluxes and PFT occurrences in traits-based models allows for flexible vegetation classifications.

Main conclusions - Given the advantages described above, we argue that traits-based modelling deserves consideration (although it will not be easy) if one is to aim for better climate projections. More >>

You will find more peer reviewed articles on 'KWR Publications'