Project Update

OPEX costs @1%TotalSolids    % Removal Rates@1%TS 
ChemicalDose rate/m3 slurry (l)Costs/m3 slurry (£)Total/m3 slurry (£)Total/100 cows (£)CHEMICAL OXYGEN DEMAND (COD)89.33
PAM (0.14% active)400.67  TOTAL NITROGEN (TN) 68.07
Sub Total Costs  2.314,795TOTAL PHOSPHATE (TP) 99.63
Power Consumption @15p/kWh  48,304ORTHO – PHOSPHATE (OP)99.09
Total Costs  6.3113,098TOTAL POTASSIUM29.33
  • Current Solid Capture Rates

Screw press – ~37% (Average)

Sample location%TS (Average)Range
Raw Pit5.41.03-8.53
SP Filtrate3.41.05-5.08
SP Cake23.2921.33-26.23
DW Store0.840.48-1.14
Decanter Centrate0.460.33-0.63
Decanter Cake16.4215.33-22.54
DAF Subnatant0.290.18-0.44
DAF Sludge2.240.32-5.41

Slurry Store – ~ 36% (as a result of dilution factor and lower                                        %TS Averages

feed solids earlier in the season and sedimentation)

Decanter – ~ 46% (Average)

DAF – ~ 37% (Average)

  • ~50% of %TS is dissolved (will increase as slurry thickens)
  • Statistical Analysis of %TS shows a good degree of confidence (P-Value = 0.05)

within data sets (indicating stability-low variance in decanter feed) and between data

sets ((indicating significant differences between influent (decanter feed) and effluent

(DAF subnatant)).

  • Still early days for reedbed performance data (180 day retention)

Next Steps

  • Maximise decanter efficiency
  • Optimise chemical dosing for higher feed %TS and flow rates

N:P:K Ratios (Cows out)

Sample locationNPK Ratios
Raw Pit5.5:1:5.5
SP Filtrate5.5:1:6.75
SP Cake4.75:1:3.75
DW Store4:1:5
Decanter Centrate145:1:365
Decanter Cake8.75:1:1.4
DAF Subnatant542:1:1192
DAF SludgeN/A

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