Possible Uses for Sludge Digestate in Agriculture: recommendations for Stormossen Oy’s plant in Vaasa, Finland
Guirado Pujol, Júlia (2023)
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202402223337
https://urn.fi/URN:NBN:fi:amk-202402223337
Tiivistelmä
Recent studies show that municipal solid waste production is projected to be at a global rate of 2 billion tonnes per year, where up to 37% of this waste will be dumped in landfills (The World Bank, 2023). Using the biochemical anaerobic digestion process, Stormossen Oy is a Finnish waste management company that primarily treats biowaste and sewage sludge to produce biogas and digestate (Stormossen Oy, 2020). Whilst most of their outcomes are monetised, the sludge digestate is currently considered as waste.
Through a thorough review of literature and European laws, the thesis aims to determine if sludge digestate can be treated as fertiliser. The final purpose was to assess Stormossen Oy on how they could implement a beneficial sludge digestate treatment. Therefore, the sludge digestate compounds information was provided by the company.
According to Regulation (EU) 2019/1009 of the characteristics of an EU fertilising product must-have, the digestate from sewage sludge cannot be used as fertiliser. However, sewage sludge can be used to obtain phosphate salts and their derivates, which can be used in fertiliser manufacturing.
Future studies might be conducted to look at the financial and environmental advantages of processing sewage sludge to produce precipitated phosphate salts and their derivates. Additionally, a more thorough review of legislation could determine if cooking oil could be used during the procedure. Also, a further scenario to be studied could be to pre-treat the sewage sludge to produce precipitate phosphate salts, followed by an anaerobic digestion process to produce biogas.
Through a thorough review of literature and European laws, the thesis aims to determine if sludge digestate can be treated as fertiliser. The final purpose was to assess Stormossen Oy on how they could implement a beneficial sludge digestate treatment. Therefore, the sludge digestate compounds information was provided by the company.
According to Regulation (EU) 2019/1009 of the characteristics of an EU fertilising product must-have, the digestate from sewage sludge cannot be used as fertiliser. However, sewage sludge can be used to obtain phosphate salts and their derivates, which can be used in fertiliser manufacturing.
Future studies might be conducted to look at the financial and environmental advantages of processing sewage sludge to produce precipitated phosphate salts and their derivates. Additionally, a more thorough review of legislation could determine if cooking oil could be used during the procedure. Also, a further scenario to be studied could be to pre-treat the sewage sludge to produce precipitate phosphate salts, followed by an anaerobic digestion process to produce biogas.