TY - JOUR
T1 - Phosphorus Removal from Manure by Mechanical Separation using Salt and Polymers
T2 - Theoretical Simulations and Experimental Data
AU - Christensen, Morten Lykkegaard
AU - Keiding, Kristian
AU - Christensen, Peter Vittrup
PY - 2020
Y1 - 2020
N2 - 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.
AB - 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.
KW - Coagulation
KW - Flocculation
KW - Solid-liquid separation
KW - Vivianite
KW - Wastewater
UR - http://www.scopus.com/inward/record.url?scp=85084402418&partnerID=8YFLogxK
U2 - 10.13031/aea.13726
DO - 10.13031/aea.13726
M3 - Journal article
SN - 2151-0032
VL - 36
SP - 175
EP - 185
JO - American Society of Agricultural and Biological Engineers. Transactions
JF - American Society of Agricultural and Biological Engineers. Transactions
IS - 2
ER -