Table 2 Analytical methods for wet chemical analyses of the digestate
Parameter | Sample pre-treatment | Analytical methods and instruments |
|---|---|---|
TS | No | DIN 12880 |
VS | No | DIN 12879 |
pH value | Sieved | Microprocessor pH meter pH 95 (WTW, Germany) |
VFA/TIC | Sieved | Titration method according to [18] |
TOC, TN | Sieved | TOC-VCSH/CSN with a TN unit (Shimadzu, Japan) |
NH4–N | Filtered | DIN 38406 E5. Spektroquant® test kit (measuring range 0.01-3 mg L−1 NH4-N, Merck. Germany). photometric measurement with MultiLab P5 (WTW, Weilheim, Germany) |
Acetate, propionate, butyrate, lactate | Filtered | High-performance liquid chromatography (Shimadzu, Japan); detector: RID-10A; column: VA 300/7.8 Nucleogel Ion 300 OA; eluent: 0.01 N H2SO4 |
Water-soluble elements (Ca, Mg, P, S, K, Na) | Filtered | Inductively coupled plasma atomic emission spectrometry ICP-AES (Spectroflame, Spectro Int., Kleve, Germany) |