A sustainable solution for pig manure treatment: Environmental compliance with the Integrated Pollution Prevention and Control directive (PIGMAN) Rena Angelidaki PIGMAN
Cost EU project - Partners
Main environmental problems caused by pig manure Contamination soil and ground water Contamination surface water Emission of green house gasses (carbon dioxide and methane) Emission of ammonia gas (acidification( acidification) Odour emission
Pig manure on Cyprus
Main objective PIGMAN To develop and test a working prototype of a digester + water treatment plant: Removal of organic matter (anaerobic( digestion ion) P precipitation as struvite N removal by partial ammonia oxidation process
Process flow chart
Anaerorbic digestion Biogas Manure Digester Water Water treatment Other Solids Compost
P removal as struvite Mg 2+ + NH 4+ + HPO 2-4 + 6H 2 O MgNH 4 PO 4 6H 2 O + H + Struvite precipitation > 90% of the phosphate is removed from the water Solids and organic matters are removes which gives 50% COD reduction and 30% N reduction Every kg P gives 7,9 kg MgAP (MgAP is a fertilizer which can be dry used)
Ammonia removal Conventional: nitrification/denitrification Novel: : OLAND = oxygen-limited autotrophic nitrification/denitrification
Flowsheet suggestion CH4-prod., COD reduction COD reduction CH4-prod., COD reduct., Part. P removal P removal, partial N removal N removal Anaerobic dig. UASB reactor Anphos Oland process Clean Waste Water Separation Pig manure 1 Biogas Anaerobic Digester Membrane Fibers filtration tank Decanted 2 Decanter effluent 4 centrifuge 3 Filtrate (permeate) biogas Storage tank Concentrate 5 6 UASB 7 ANPHOS 8 OLAND
DTU s activities: Codigestion of manure together with animal byproducts Ultrafiltration of centrifugate Struvite precipitation UASB reactor for further COD removal Oland process
Hegndal biogas plant Reactor Decanter Centrifuge Ultra filter
The effluent from the decanter centrifuge is collected in an underground tank (Hegndal Biogas plant).
The tank (H=170cm, D=130cm) where the membrane was installed Technical specifications of Mitsubishi membranes MBR test unit given by the supplier: Membranes: Submerged, capilliar Producer: Mitsubishi Rayon Company, Japan Surface membrane: 1.5 m2 Withdrawal flow: Back flush flow: 30 l/hr 1.5 * withdrawal flow = 45 l/hr
Membrane filtration unit.
The liquor in the membrane filtration tank
Foaming 12 hours after initiation of the filtration
Clogged membrane after 3 days of operation
The liquor after membrane filtration
Biofilm microbial community overview (DAPI) Biofilm formation on the membrane surface Microbial communites in the biofilm studied by FISH Eubacteria (EUB 338 and EUB 338+) Archaea (ARC 915)
Conclusions for the membrane filtration step Maximal obtained outflow rate -12 L filtrate per hour. Aeration of the membrane creates foaming after 12 hours. Clogging of the membrane was observed after 3-43 days of operation (back flushing with water was not able to completely remove accumulated particles). The membrane was not suitable for practical application (filtration of the decanter centrifuge effluent).
UASB (Upflow( anaerobic sludge blanket) experiments
Future activities Treatment of the UASB effluents with: Anphos Oland