Phosphorus Removal from Manure by Mechanical Separation using Salt and Polymers: Theoretical Simulations and Experimental Data

Morten Lykkegaard Christensen, Kristian Keiding, Peter Vittrup Christensen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Full-scale separation apparatuses were used to process mink and sow manure. Mink manure was pretreated with iron sulfate and polymer; pig manure was pretreated with only polymer. Testing was done to study how adding chemicals affected phosphorus removal. Chemical equilibrium simulations show that raw manure contains several minerals, i.e., struvite, calcium phosphate, and vivianite. The estimated mass of struvite fit well with the amount of magnesium measured in the solid material. The amount of calcium phosphate precipitation depended on the stability constant of the complexes of organic material and calcium ions, estimated at pK = 3.5-4. With polymer addition, it was possible to remove mineral-bound phosphorus but not organic-bound phosphorus and orthophosphate. With iron salt addition, it was possible to remove both phosphorus minerals and dissolved orthophosphate. The molar ratio between orthophosphate and iron ions in the precipitate was measured to be 2:3. These data fit well with the chemical equilibrium simulations, which predicted that vivianite would form when the iron ion concentration increased. The simulation also indicated that the amount of struvite decreased slightly with iron addition.

Original languageEnglish
JournalAmerican Society of Agricultural and Biological Engineers. Transactions
Volume36
Issue number2
Pages (from-to)175-185
Number of pages11
ISSN2151-0032
DOIs
Publication statusPublished - 2020

Keywords

  • Coagulation
  • Flocculation
  • Solid-liquid separation
  • Vivianite
  • Wastewater

Fingerprint

Dive into the research topics of 'Phosphorus Removal from Manure by Mechanical Separation using Salt and Polymers: Theoretical Simulations and Experimental Data'. Together they form a unique fingerprint.

Cite this