Buying 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. 

This is possible thanks to wastewater bio-refinery technologies like and it enables to plan activities, to reduce uncertainties and to not miss any opportunities to: 

  • buy and/or sell WasteWater by- or recovered products and for which wastewater-based epidemiology can be tracked;
  • deliver and be rewarded for WasteWater enabling optimal up-cycling;
  • secure investments, markets and solvency directly and indirectly linked to wastewater.


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

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

– benefit from the reduction of environment, social and economic problems and from more virus detection in wastewater; those outcomes can be directly allocated to them e.g. for carbon reduction and for data for early warnings 

– get solvent and organised sales of their products or services thanks to our Back2You rewarding scheme converting wastewater into an asset. 

The Sellers of WasteWater By-or Recovered Products choose the WasteWater Exchange because they: 

– 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 for optimal up-cycling and for advice and follow-up of virus detection in wastewater;

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


Please complete our form available at the bottom of this page for your offers and/or demands of products recovered or made from wastewater enabling you options of:

  • delivery/collecting places
  • delivery as input of a product or service
  • request of exchange of wastewater by-products against wastewater 

Water is the common element of every product and service. It's implicitly  the most traded good as water footprint or unavoidable input. 

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

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

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 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.

The value and level of cleanliness of reclaimed water depend on the item or service to be produced thanks to this water.


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

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: 


For sellers of energy from wastewater looking for blended finance for their wastewater infrastructures; we recommend Blue Yellow a  fintech platform connecting renewable energy projects with investors.

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 valorized 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 ( This is measurable according to ISO standard 14046.

To reduce costs, secure markets and for a positive value chain, the fashion industry, cotton traders or trade finance, insurers, investors and/or cotton users can prioritise products from crops irrigated partially from treated wastewater and/or with organic fertilisers from wastewater and/or renewable energy from wastewater.

The cotton farming area will then get improved access to sanitation with virus detection in wastewater for early warnings and monitoring and will therefore get local access to some of the products generated thanks to their wastewater.

The W2AREX wastewater suppliers in this transaction gets also dividends or rewards if their raw materials enable efficient wastewater circular economy: in some cases this can lead to financial inclusion.

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).

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 matches it with potential wastewater supplies. Contract for wastewater supplies include wastewater quality request to enable 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. 

Wastewater up-cycling in bio-refineries creates tremendous opportunities for circular economy.


International coffee trade = about 80 billion m3 virtual water exports = 6% of the international virtual water flows in the world.
ICE [NYBOT] is trading coffee up to 3 years ahead: part of the water footprint for irrigated coffee could be allocated from wastewater - e.g. from the farmers and from coffee washing - transformation decentralised infrastructures. In addition to created access to sanitation, this can generate energy e.g. for green mobility or transport and therefore reduce costs and risks.