Flocculation, coagulation, and precipitation of manure affecting three separation techniques.
The effects of polymer flocculation before manure separation were investigated, through testing both a linear and a branched polymer. Centrifugation removed 60% of phosphorus from raw manure (control), whereas raw manure clogged the filters during gravity drainage and pressure filtration. At optimum flocculation, 95% of phosphorus was removed using any of the three methods. Optimum flocculation was achieved when 2.8meq of polymer charge was added per kg of manure, corresponding to 0.6g/kg of highly charged, branched polymer or 0.85g/kg of less-charged, linear polymer. If 10mmol of ferric chloride was added per kg of manure, 2% more phosphorus was precipitated and removed. The linear polymer formed loose flocs and was superior for reducing turbidity, whereas the branched polymer formed compact flocs that deflocculated at high polymer doses. The branched polymer, however, was best for pressure filtration, as overdosing with the linear polymer resulted in high resistance.
Hjorth
Maibritt
M
Faculty of Agricultural Sciences, Aarhus University, Schüttesvej 17, 8700 Horsens, Denmark.
Christensen
Morten Lykkegaard
ML
Christensen
Peter Vittrup
PV
D000818:Animals; D011232:Chemical Precipitation; D002625:Chemistry, Organic / Q000379:methods*; D005374:Filtration; D005427:Flocculation; D008372:Manure; D009391:Nephelometry and Turbidimetry; D010758:Phosphorus / Q000032:analysis; D011108:Polymers / Q000737:chemistry; D013552:Swine
D008372:Manure; D011108:Polymers; D010758:Phosphorus