News

Ecological fertilizer from wastewater nutrients

By using the innovative NPHarvest-process wastewater treatment plants can get an efficient pretreatment while producing ecological fertilizer simultaneously.
 NPHarvest -laitteisto toiminnassa Gasumin biokaasulaitoksella Riihimäellä
NPHarvest -equipment in action at Gasum's biogas plant in Riihimäki.

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. 

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. 

The project has been funded by the Ministry of Environment and it has been executed in partnership with many industries of the field. Aalto University has collaborated in the project with Helsinki Region Environmental Services Authority HSY, Nordkalk, Gasum, Biolan, Teollisuuden Vesi, Kemira and Outotec.

 

More information: 
Professor of Practice Anna Mikola
[email protected]
+358 40 7176 552
 

  • Published:
  • Updated:
Share
URL copied!

Read more news

Sakari kuvattuna Aalto-yliopiston tiloissa.
Research & Art, Studies Published:

Sakari Poikkimäki is replacing harmful chemicals with enzymes: ‘We can use small biological organisms in many everyday products’

Chemical engineering alumnus Sakari Poikkimäki works as a fermentation expert at Roal Oy, a company that manufactures enzymes. Studies at Aalto University School of Chemical Engineering lead to a dream job where small living organisms are harnessed for good.
Iita Kejonen kuvattuna Aalto-yliopiston tiloissa.
Research & Art, Studies Published:

Iita Kejonen is involved in recycling battery metals from electric cars: ‘By working in industry, I can influence the development of the entire field’

Studies in materials science and engineering at the School of Chemical Engineering led to work with battery metals and minerals. As a Technology Manager, Iita can influence the development of responsibility in the entire automotive sector.
Students
Studies Published:

School of Chemical Engineering opens 24 summer jobs in research groups for 2023

We're looking for enthusiastic students to join our team for the summer. The ideal candidate is highly motivated and able to e.g. assist and carry out various lab tasks, run experiments and develop research skills. This is a unique opportunity to gain hands-on experience in research projects, and work side-by-side with doctoral researchers and post docs.
Image and photo by Aalto University, Giulnara Launonen. MMD logo by Aalto University, Mithila Mohan
Research & Art Published:

Multifunctional Materials Design: Highlights of 2022

Our group's milestones of the previous year