How different are manometric, gravimetric, and automated volumetric bmp results?

摘要: The objectives of this study were to: (1) quantify differences in biochemical methane potential (BMP) measured using three measurement methods, including two popular methods (a commercial automated system (AMPTS II) and manual manometric) one newer method (gravimetric), (2) assess the importance mixing position sequence. Powdered microcrystalline cellulose was used as substrate simultaneous tests. All gave similar results (<8% difference mean BMP) reasonably accurate (recovery 80–86% theoretical maximum BMP). Manometric BMP values consistently lower than gravimetric by 4–5%. Precision for (relative standard deviation (RSD) about 7%) (RSD 1–3%). Mixing after biogas resulted 3% higher both before, due to CH4 production from blanks. This effect may be linked a fraction that remains dissolved or even attached bubbles, suggests before is preferable. volumetric (mode 2) very (1% different). However, kinetic analysis showed faster with method. could come an error estimation rate method, increase degradation better mixing. Both automatic measurements met current validation criteria BMP, but RSD exceeded limit.