Innovative treatment technologies – Application of AiRO technology

In the first instance the focus is on ‘Innovative Desalination Technologies’, in which Dutch innovations and knowledge are applied to increase the efficiency of surface water and/or seawater treatment and effluent reuse compared to existing reuse techniques, such as ultrafiltration (UF) and reverse osmosis (RO).


Membrane fouling is one of the biggest problems with the application of nanofiltration (NF) and RO. A clean and cheap solution to the fouling is offered by AiRO, the regular cleaning of membranes with water and air. For years now, KWR has been researching innovative AiRO techniques within the contexts of research programmes like BTO, TTI and Innowater. The AiRO concept renders effluent treatment more cost-effective through a reduction in the number of treatment steps, improved design and better operational management. The research places particular emphasis on identifying smart combinations of techniques in a hybrid AiRO, or other innovative techniques for desalination – e.g., ion exchange (IEX) or membrane distillation – and for processing of concentrate (EFC).

With this project the partners want to demonstrate the added value of the application of innovative desalination technologies (AiRO) to the effluent of the Harnaschpolder and/or Epe (effluent Nereda® technology) WWTPs, compared to the use of existing technologies (UF, RO). They also want to further optimise the AiRO design and operational technique, start optimising the operational techniques in AiRO installations (such as timing and frequency of cleaning) using data analysis (DWP Botlek), explore new AiRO applications such as for effluent water, and valorise and export the AiRO concept abroad.

In 2013 the project’s consortium membership was enlarged with the inclusion of Royal HaskoningDHV.


The national and international marketing process has got underway and has involved an examination of the replication potential of the application of AiRO to surface water, in other market segments, and for other water types (effluent reuse, desalination, industrial water and residual streams).

The market potential of the AiRO technology was clarified on the basis of the following criteria: (i) costs, (ii) field of application and (iii) protectability.

The cost calculations show that the application of AiRO is of great interest, particularly for used water and surface water; compared to the state-of-the-art scenarios, AiRO offers savings of up to 30%. In a growing global water market for RO membranes, the field of application for AiRO can be considered very favourable, particularly in the rapidly developing Asian and Gulf markets. AiRO’s IP position, however, is weak, because of one expired patent and a new patent request whose prospects are not considered promising. The IP position of the AiRO concept could be strengthened through the development of an advanced process controller, which bundles unique design, process and application knowledge, as a means of keeping ahead of potential competitors. Nevertheless, because of the excessively high costs involved, and the insufficient number of concrete cases for the development of an AiRO controller, a decision has been made to end the project despite AiRO’s interesting substantive application possibilities.