Waste Treatment by Bionutrient Recycling

Dr. Katja Hansen is a long time collaborator with cradle-to-cradle cofounder Dr. Michael Braungart on the implementation of cradle-to-cradle design. She helped co-develop the first bio-nutrient recycling pilot project for the original UN Rio Sustainability meeting many years ago. She became a founding contributor to the Brazilian NGO “O Instituto Ambiental” which took over the technology she developed and built facilities across Central and South America. Some facilities were built in Haiti where they survived a devastating earthquake and continued purifying water and recycling nutrients when other sanitation systems failed. The technology is now supported by UNEP in Haiti.

Biological treatment of human waste is defined as the natural processes of purification of wastewater with nutrient recycling for reclamation and agricultural and renewable energy (biogas) obtained in the process. Bionutrient recycling is an effective cradle-to-cradle biological treatment methodology that treats human or animal sewage and recovers a maximum amount of nutrients in a way that is healing to the environment. The sewage is filtered through biodigesters and then the treated effluent is dispersed into root zones for “fertigation”.

The effluent flows through digesters and contact filters, oxidation ponds, sedimentation, aeration, fish and macrophytes. 

This technology heals the human habitat, adds value to the supply chain and preserves the environment, since the treatment water returns to the river in the state of bathing without contamination risks to nature.

  1. The sewage produced is collected and taken to the biodigester closest to the residences.
  2. The sludge is periodically removed, dried in the sun and used as organic fertilizer.
  3. The gas is used in the kitchen of the Community Centres where the biosystem was deployed.
  4.  The water flows into the recycling station nutrients settling tanks with aeration and oxygenation green algae
  5. In the next step, water passes through blades subtle, flowing into the fish tank where they grow tambacús, pacu, curimatãs, tilapia and follows gravity to the tanks macrophyte

Where there is constructed tanks, a biological filter is installed after the housing compensation digester, followed by the root zone by evaporation filtering and consume most of the effluent

Advantages of digesters:

  • Totally waterproof;
  • Cleaning the digester every 5 years on average: The material can be used as manure after drying in the sun for 30 days.
  • Cost: Although the higher initial cost, maintenance-free and generates nutrients and bio-gas.
  • It can be integrated into the landscaping is complete with lakes of aquatic plants and fish.
  • Its effluent can be utilized in irrigation ferti infiltration in roots.
  • It has approval from environmental agencies.

Digesters are airtight and equipment used to treat organic waste. Are able to reduce up to 70% organic matter and therefore are coupled to biofilters that increase their ability to remove organic load, reaching 90% efficiency. The digesters have three stages of fermentation: acidogenic, and methanogenic acetogênica. This latter is responsible for the production of biogas, a mixture of methane and carbon can be used as a heat source, fuel and energy. The resulting biosolids these fermentation processes is of high nutritional value for the plants and the liquid effluent generated can be used for drip irrigation and cultivation in general.Dr. Katja Hansen, senior researcher at the Rotterdam School of Management, Erasmus University co-designed, constructed and scientifically tested one of the world’s first bionutrient recycling systems presented at the 1992 UNCED Rio Earth Summit. From 1992 to 1998 she was the scientific and project director of an EU funded project for bionutrient recycling in Brazil and China. The pilot projects demonstrated safe and highly productive re-use of nutrients from effluent, generating clean water as a byproduct.


If you want to implement a bionutrient recycling system, proceed to the detailed instructions and process description available on the Hamburger-Umweltinst website. Or goto the InGienous Designs webpage.