Sourcing or Selling Wastewater by- or recovered products


The WasteWater Exchange© , W2AREX® collects, filters and matches offers and demands of wastewater by- or recovered products such as clean water, renewable energy and bio-fertilisers and for which wastewater-based epidemiology can be tracked. This is possible thanks to wastewater bio-refinery technologies like  

The Buyers of WasteWater By- or Recovered Products use the W2AREX to:

– plan and secure their sourcing at cheaper costs than from classical alternative,

– benefit directly from the reduction of environmental, social and economic risks and from more virus detection in wastewater;  

– get solvent and organised sales of their products or services thanks to our Back2You rewarding scheme. 

The Sellers of WasteWater By-or Recovered Products can: 

– get the best plans and deals for their products derived from wastewater,

– benefit from our organised sourcing of wastewater with content influenced though our Back2You Rewards for quality content enabling optimal up-cycling;

– obtain organised finance to upgrade or build their wastewater transformation factory. 



About 97,25% of the water on our planet is the form of oceans and seas. Freshwater counts for about 2.75% of about 39 million km3 water: 75% of it is trapped in glacier and ice and 24,5% is underground (source PricwaterhouseCoopers, 2012).

Water demand will exceed water resource availability by 2030 according to the Word Economic Forum. Water, H2O is implicitly  the most traded good as water footprint or unavoidable input of goods or services. 

Water is essential to the existence of Human beings and of the flora and fauna. Water is therefore not just an economic good as it also a social and environmental good.

Reusing wastewater enables to not pollute the environment and to release conflicts and pressures on that limited resource.

There are 2 types of reclaimed water available for sales/purchase through our platform:

  • potable water
  • treated wastewater for irrigation as per ISO 16075


Wastewater bio-factories can generate more energy than needed for wastewater up-cycling and can produce storable energy such as pellets and hydrogen.

Decarbonised renewable energy from wastewater can be available on PPA Power Purchase Agreements.

There are different forms of renewable energy from wastewater.  For example,

  • algae can grow on wastewater, clean it and be transformed into biofuel
  • treated wastewater can be used for hydro-power
  • hydrogen can be produced and stored thanks to wastewater
  • pellets can be made by mixing sludge with residues of wood 
  • “green power station” with anaerobic digestion during which micro-organisms break down materials from wastewater (to which solid bio-wastes can be added):  the biogas/methane gas produced from this process is then used to generate heat and electricity and or used as gas to power e.g. vehicles. The wastewater transformation factory can help also to solve issues of solid wastes as follows: 


Gold, silver or other metals can be recovered from wastewater (see:

For example, chromium used in metal-plating industries or leather tanning can be recovered in wastewater thanks to specific filters and technology. Chromium-6 (hexavalent chromium) bath can be re-used/re-cycled for several cycles of plating or dyes by filtering iron and other contents. This also enhances the quality of plating. The sludge that comes out after filtration can then be recycled safely into clean water and/or biogas and/or other outputs.

Recovering nutrients from wastewater is key for healthy food security and for sustainability. 

- Phosphorus is used for fertilizers, as an animal feed additive, treatment of metals, batteries, fire extinguishers, ...etc.

Every year, the drains and sewers carry more than 16 million tonnes of dissolved nitrogen and 3m tonnes of phosphorus. Four-fifths of the first element and half of the second are supplied by human urine, and the resource isn’t simply wasted: this global excess of nutrients goes on to nourish dangerous levels of plant growth and increase oxygen demand in the waters, restraining aquatic life e.g. in oceans.

- Sodium is washed out from rocks and soils. Many laundry detergents use sodium salts as fillers, adding significant sodium to the wastewater. Lighter than water, sodium conducts heat and electricity easily and is used for batteries. Sodium is used in different forms; for example Sodium vapor is used in streetlights and produces a brilliant yellow light.

- Ammonia in wastewater is a contaminant and hazardous to the environment. Ammonia in a fuel cell is nonetheless energy dense in volume and comparable to hydrogen in performance

Transforming wastewater sludge in bio-cements can:

  • decrease the cement industry greenhouse gas emissions
  • reduce long distance transport of this construction material
  • enhance the durability of building materials and structures

Polymers can be recovered from oily wastewater and/or generated from wastewater.

Organic material can be recycled as polymers for bioplastics. For example, algae grown in wastewater from livestock farms, municipalities, distilleries, etc. can be transformed into biofuels or biopolymers. 

Methylene blue dye can be recovered from textile or tannery wastewater and reused e.g. to store and to produce energy.

Recovery of silk sericin from the filature wastewater.

Sericin protein has high additional value in many industries such as textiles, pharmaceuticals and cosmetics.

Biochar can be produced from wastewater sludge pyrolysis (treatment in high temperature at zero- or low-oxygen environment) and biochar can be used to filter wastewater

Biochar is used as a soil amendment for carbon sequestration, retaining water and improving crops.

Biochar is used as an adsorbent to remove toxic metals, organic pollutants, and pathogensfrom wastewater. 

CO2 credits are possible through biochar as carbon remover.

 The W2AREX market players can know 


the CO2 carbon footprint has been sequestered and absorbed thanks to wastewater transformation via third-party independent audits.


Source of the image: Hoekstra & Chapagain

A cotton T-shirt has an average water footprint of 2’700 litres (www.waterfootprint.organd according to ISO standard 14046). About 8 million tons of fertilisers and 200'000 tons of pesticides are used every year for cotton crops. 

To reduce production costs and risks, to secure markets and to add a positive value chain, the fashion industry, cotton traders or trade finance, insurers, investors and/or cotton users can prioritise products with inputs from transformed wastewater such as organic fertilisers and produced and renewable energy. Those environmental friendly wastewater by-products are usually cheaper than the classical alternatives.

Prioritising inputs from transformed wastewater drives improved access to sanitation with routine virus detection in wastewater for early warnings,  monitoring and tracking.

Through our Back2You Rewards, the providers of wastewater (= raw materials) with optimal quality for up-cycling  into inputs for those apparels can therefore get exchange their resources with products or services (in some cases this can lead to financial inclusion) adding value to wastewater (e.g. biodegradable soaps) and/or with inputs from wastewater (e.g. telecom services using renewable energy from wastewater).

The W2AREX® filters the offers and the demands of treated wastewater, fertilisers and/or energy  to be delivered and off-taken at an agreed period and matched it with wastewater supplies.

1kg of refined cane sugar has an average water footprint of about 1'400 liters (see and ISO standard 14046 ). The Buyer of treated wastewater for irrigation as per ISO 16075 might be the farmer or its client buying sugar. If, for example,  only 1% of water used to produce sugar comes from treated wastewater, a cargo of 20'000 tons of sugar can cover sanitation infrastructure for 13'698 people living near the sugar plant (1,5 m3/ton water footprint per 20'000 tons / 100 for only 1% of water used from treated water = 300'000m3 = 60 litres/day wastewater of that population during 365 days).

We link this to a program of housing equipped to harvest rain and floods water and become providers of  wastewater with quality enabling efficient circular economy and virus detection to prevent virus outbreaks. In case of necessary lock down in the wastewater collection area, the rewards are allocated to secure basic needs for isolation, sugar could be potentially supplied in that context (e.g. via State's public procurements for food security).  

Wastewater up-cycling in bio-refineries creates tremendous opportunities for circular economy and for investments in solid organic wastes and wastewater. 

Example enabling to correlate trade finance with wastewater transformation finance: The trades international coffee trade involves about 80 billion m3 implicitly water exports; this is about 6% of the international virtual water flows  in the world.
ICE [NYBOT] is trading coffee about 3 years ahead of deliveries: part of the water footprint for coffee could be allocated from wastewater transformed in decentralised biorefineries. In addition to created access to sanitation and/or releasing of pressure on fresh water resources, this can generate energy e.g. for green mobility or transport and biochar enabling sustainable agriculture and carbon credits.