Method for recovering N, K, and P from liquid waste stream
AssigneeUniversiteit Gent
InventorsArne Verliefde, Sebastiaan Derese
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method for recovering N, K, and P from liquid waste stream, preferably from a stream of urine, or from a stream comprising excreta (e.g. faeces, manure, digestate, fertilizer), or from (concentrated) wastewater, for example, municipal (e.g. sewage, septic) and/or industrial wastewater (e.g. food and feed industry, agriculture, mining, etc.); more preferably from urine, such as human or animal urine; most preferably from human urine.
Claims12
Method for recovering Nitrogen (N), Potassium (K), and Phosphorus (P) from a liquid waste stream, wherein the liquid waste stream comprises N, K, and P, the method comprising the steps of:
- a. removing a Nitrogen (N)-comprising compound from the liquid waste stream, thereby obtaining a Nitrogen (N)-poor solution and the Nitrogen (N)-comprising compound;
- wherein during step a. the concentration of Nitrogen (N) in the Nitrogen (N)-poor solution is at most 100.0 mg/l, as measured using a Kjeldahl measurement method according to ISO 5663:1984;
- b. concentrating the Nitrogen (N)-poor solution through water removal, thereby obtaining a concentrated solution;
- wherein step b. is performed until the water removal is at least 50.0%;
- c. adding a nucleating agent to the concentrated solution;
- and, d. precipitating potassium struvite MgKPO4.6H20 from the concentrated solution, thereby obtaining potassium struvite MgKPO4.6H2O and a waste solution, wherein step a. and/or step b. is performed through membrane distillation and wherein in step d. no magnesium ammonium phosphate (ammonium struvite, MAP) is formed.
Dependencies are inferred from the claim text.