Psychrophilic
Digestion of Pig and Dairy Cattle Manure
Procedures were evaluated for anaerobic digesters (fed-batch,
CSTR) at psychrophilic temperatures (5-20°C). For continous systems
hydraulic retention time was 20 days. Accumulation systems showed retention
times in the range of 6 months.
Advantages
of accumulation systems are:
-
COD Reduction: 46%
-
Reduction of organic dry matter: 55%
-
Reduction of NH3 emission
-
Adapted to vegetation period
Disadvantage:
-
High volumes of reactor (e.g. 400 m3 / 35 cattle units)
|
Liquid manure
|
Nutrient content [kg]
|
Cattle unit (max)/ha
|
|
m3
|
N
|
P2O5
|
K2O
|
|
|
Dairy Cattle
(7,5 % TM)
50
55
60
|
200
220
240
|
100
110
140
|
250
275
300
|
3
3 cows over
2 years
|
|
Pig manure
(7,5 % TM)
40
45
50
|
220
245
270
|
180
200
220
|
100
110
120
|
3
7 brood sow + piglets
|
|
Hen
(15 % TM)
20
25
30
|
200
250
300
|
160
200
240
|
100
125
150
|
1
250 hens
|