Google Play icon

Ecological fertilizer from wastewater nutrients

Share
Posted December 19, 2019

Wastewaters contain large amounts of phosphorus and nitrogen, which are valuable nutrients. Aalto University’s NPHarvest process enables recovery of these nutrients as clean ammonium sulfate and sludge containing phosphorus and calsium, which can be used as ecological fertilizers. The process produces ecological fertilizer as an end-product and, at the same time, saves energy and natural resources by recycling nutrients of wastewater.

Nutrient recovery is based on membrane filtration technique 

Solids and phosphorus in the wastewater are separated in ballasted sedimentation using a side-product of lime production. The nitrogen recovery process is based on transforming ammonium nitrogen to ammonia gas. Ammonia is separated by stripping through a gas permeable hydrophobic membrane. This enhances the efficiency of the process significantly.

NPHarvest -equipment in action at Gasum’s biogas plant in Riihimäki. Image credit: Aalto University

Nutrient recovery happens as a part of normal wastewater treatment process when using the NPHarvest process. The process is beneficial especially to those wastewaters which have more nutrients than the usual municipal waters. Suitable wastewaters for the process are for example reject water from digestion, urine, landfill leachate and septic waste. NPHarvest technique has been proved to be efficient during pilot testing in real environments.

The process has commercial potential in agriculture and wastewater industry

The process can be commercialized in the agriculture business as all the demand for fertilizers in Finland could be fulfilled by recovering nutrients from different biomasses and wastewaters. Also, those farms that have their own digestion tanks, can economically benefit from the process as the digestion reject water can be used for nutrient recovery and produce a recycled fertilizer product.

Reject water is also produced at wastewater treatment plants and biogas plants. Composting plants also produce nitrogen rich liquid wastes. Besides these reject waters, water originating in landfill sites has high nitrogen content. Hence, there is a demand for a technology that enables nutrient recovery from liquid wastes. A business model for NPHarvest process and its end-products has therefore been developed.

Source: Aalto University

Featured news from related categories:

Technology Org App
Google Play icon
87,553 science & technology articles

Most Popular Articles

  1. An 18 carat gold nugget made of plastic (January 13, 2020)
  2. Anti Solar Cells: A Photovoltaic Cell That Works at Night (February 3, 2020)
  3. Toyota Raize is a new cool compact SUV that we will not see in this part of the world (November 24, 2019)
  4. Nuclear waste could be recycled for diamond battery power (January 21, 2020)
  5. Physicist Proposes a Testable Theory Stating that Information has Mass and could Account for Universe s Dark Matter (January 24, 2020)

Follow us

Facebook   Twitter   Pinterest   Tumblr   RSS   Newsletter via Email