Temp(°C) HRT(d) Volatile Acid Concentration (mg/L)
Acetic Acid Propionic Acid i-Butyric Acid n-Butyric Acid i-Valeric Acid n-Valeric Acid i-Caproic Acid n-Caproic Acid Heptanoic Acid Total as Acetic Acid
20-40 25 5.5 26.6 15.6 8.4 9.8 <0.01 11.7 3.9 5.7 60.0
20 44.0 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 44.7
15 3.0 26.0 10.7 11.3 9.7 1.3 3.3 2.4 2.5 50.0
10 53.8 56.9 35.7 8.2 11.5 5. 9.0 4.7 16.9 154.8
15-25 25 54.1 73.6 13.7 18.3 3.9 <0.01 2.2 5.4 20.0 151.0
20 70.8 102.1 19.1 26.0 19.8 4.7 6.1 6.1 58.4 231.8
15 207.4 92.0 18.5 27.6 19.7 4.1 6.6 4.3 59.4 362.5
10 645.0 431.4 139.7 38.6 36.0 25.0 22.7 17.8 30.1 1187.0
Raw Manure 1548.4 283.5 44.5 60.5 40.2 21.0 7.0 11.3 37.1 1913.0
Table 4: Volatile fatty acids.