The aim of the project is to identify anddemonstrate technologies that are:- robust and reliable- able to handle a varying water composition- have no need for extensive pretreatment- able to cope with fouling components- available on short term.A feasibility study performed by TNO andWUR showed that for water cycle closure inthe greenhouse horticulture both reversedosmosis (RO) and Memstill® membranedistillation (MD) offer promisingperspectives. Memstill® has advantages inutilising waste heat from the greenhouses(fig.3).All technologies have been researched onlab-scale (fig. 4).

From november 2011 to june 2012Memstill® and RO are demonstrated at pilotscale (fig 2., app. 1 m3/h) at Olij Roses (DeKwakel, Aalsmeer, NL).The focus during the study (fig. 5):1. Recovery of water and retention of thevarious components;2. Fouling behaviour;3. Influence of the components present(nutrients, pesticides, salt) on performance ;4. Technical and economical evaluation.First results of the Memstill® pilot:- Quality destillate: suitable for irrigation;- Water recovery of > 85% of drain;- Fouling (scaling) is an issue.The project will be completed by setting up abusiness case together with all stakeholders(institutes, greenhouse horticulturecompanies, OEMs and water boards) to aidthe implementation of the technology.

THE PROJECT

MEMSTILL®FOR CLOSINGWATER CYCLESIN GREEN-HOUSE HORTI-CULTURE

Appelman W.A.J., TNOCreusen, R.J.M., TNOJurgens R.M., TNOFeenstra L., TNOKuipers N.J.M., TNOVan Medevoort J., TNOZijlstra M., TNOVan Os, E.A., Wageningen URwilfred.appelman@tno.nl;TNO Water Treatment,PO 342, NL-7300 AH Apeldoorn,The Netherlands

TNO's research group Water Treatment is workingtogether with Wageningen UR, HellebrekersTechnieken and Bruine de Bruin on closing the watercycle in Dutch greenhouse horticulture companies.Memstill® membrane distillation seems a promisingtechnique.

The project is carried out by TNO,Wageningen UR GreenhouseHorticulture, Hellebrekers TechniekenB.V., Groen Agro Control, Fytagoras, andLTO Groeiservice in cooperation withprojectpartners and financers:Productboard Horticulture, Ministery ofInfrastructure and Environment,Interpolis, Waterboards Delfland,Hollands Noorderkwartier, Rivierenland,Peel en Maasvallei, Hollandse Delta,Priva B.V, Hortimax b.v., Bruine deBruin B.V., Stolze B.V., Bayer, Syngentaand Basf.

PARTNERS AND SPONSORSAlthough greenhouse horticulture companies alreadyapply recirculation of their drain water, still variouswaste water streams and part of the drain-water aredischarged. This is necessary due to theaccumulation of salts (sodium, chloride), growthinhibiting species or because these streams can notbe reused due to the risk of diseases.Emissions of nutrients and pesticides are undesirableenvironmental and economical issues. To comply tothe European Water Framework Directive thegreenhouse horticulture sector requires commerciallyfeasible technologies to treat the discharge water andto obtain a so-called ‘practically zero emissiongreenhouse’ by the year 2027. Fig. 1.

WATERPROOF GREENHOUSE HORTICULTURE

INTRODUCTION

FIRST MEMSTILL® PILOT RESULTS

3) Principle of Memstill® membranedestillation

4) Memstill Water fluxes, lab and pilot

5) Memstill® fluxes vs. temperatures

2) Impression of Memstill® pilot at Olij Roses

1) Closing water cycles in greenhouse horticulture