Aquanos : When waste water become a real ressource

Visit of Aquanos

We leave Tel Aviv, 2 hours in advance, confident in the futur, with our google map route;  direction : Netanya. The second bus let us at the edge of the highway, where we had to change of bus and here the adventure began… There were some bus stop, that’s right, but the only one we needed seems to have disappeared for ever. After have missed to be killed 2 times crossing the highway, we just gave up and take an other bus to the center before jump into a taxi. We finally arrive more or less on time at the direction indicated on the aquanos website. Moment of surprise : we are in a residential district, in front of a house which seems uninhabited… After few minutes of wandering, a neighbor saved us when we pronounced the name of Udi Leshem, “Oh you are looking for Udi, he just moves on the other side!” and immediately he introduces us in Udi garden, where we really found him, a bit disconcerted by finding us here. And it’s like we found ourselves at the breakfast table, filming and questioning  Udi about the Aquanos technology and his way of thinking water ressources in Israel. It was an exciting and very friendly meeting! (thanks to Udi who just made like if every thing was normal even if we were nearly taking him hostage in his own home… Yes because it was really his personal direction on the website, and he was not waiting us at all as their office is in Tel Aviv just like 500m from our hostel!

So here we are !


After this strange beginning, we get into the debate. The Aquanos philosophy could be resumed in two main points :

  • Consider waste water as a real ressource. For them, recycling is not only something great for the environment, but really a way to have new ressources.
  • Always work with local compagnies, after a local need expression and with a minimum support of one year locally.

Aquanos with its 5 years lifetime, knows well that its market is not developed countries, because these one have already all the needs fed, with technologies financially inaccessible for Southern Countries. That’s why, they are setting up projects mainly in East Africa and India.

The Aquanos idea comes from simple assessments about the traditional technologies used in waste water treatment. ( for information, these technologies work with bacterias which degrade organic material. Bacterias are fed with di-oxygen brings by air injection)

  1. The main energetic expenditure and so the main economic expenditure is the process of air injection. And at the same time it’s a really inefficient process because the air contains only 20% of oxygen. As example, 5% of the US energy expenditure is devoted to waste water treatment.
  2. Traditionnel process produce lot of slugs, which are other additional environmental and financial costs.

Idea is so pretty simple : find an other way to produce this oxygen nearly, to make the system more efficient and more economical. Aquanos decided so to use the symbiotic relation between microorganism (bacteria) and algae. What does it mean?? Algae as every plant produces oxygen and consumes CO2. So algae feed the microorganism with the oxygen produced and feed itself with the CO2 rejected by the CO2 produced by bacterias when the destroy the organic material.

Sans titre

The idea is not really new, the real innovation is the way to set it up. In the former algae process, algae, bacterias and waste water were together and so, when the waste water was charged, the sun cannot penetrate the solution and algae don’t grow up well, so the process took longtime and was uncertain. And so, the real innovation is to separate the algae and so the oxygen production from the rest of the process.

An Aquanos factory it’s 5 big steps inter-connected :

  1. The waste water arrival : anaerobic treatment (= without oxygen) by bacterias. 70% of the organic material and 80% of solid wastes disappear. Some methane is produced by this process.
  2. Methane is used to produce some energy for the plant operating.
  3. Water from the step 1. is treated by an aerobic (= with oxygen) treatment with bacteriasDSC_0007
  4. Oxygen production by algae in a separate cistern. aerobic treatment and oxygen production are linked to feed bacterias in oxygen.
  5. Separation of solid and liquid by sedimentation and filtration.

Water produced by such a factory can be used directly for agricultural needs. There is not technical limit to make some drinking water, it could only be more expensive because norms are more selective.

As expected, Udi didn’t have any waste water treatment plan in his garden, so we went for a courtesy visit to the Aquanos test plant at the south of Tel Aviv the day after, and we meet there Daniel who make us a full scale demonstration.

Aquanos in few figures it’s :

waste water treatment of 1 m3 ~ 0,20 euros

20 to 40% less costs than for a traditional process

80% of the energy saved

no sluges

projects in East Africa and India

A start-up of 5 years lifetime

5 fantastic and motivated persons : thanks Udi and Daniel for the warm welcoming!