Improving Inter-Laboratory Reproducibility in Measurement of Biochemical Methane Potential (BMP)

摘要: Biochemical methane potential (BMP) tests used to determine the ultimate yield of organic substrates are not sufficiently standardized ensure reproducibility among laboratories. In this contribution, a BMP protocol was tested in large inter-laboratory project, and results were quantify sources variability refine validation criteria designed improve reproducibility. Three sets carried out by more than thirty laboratories from fourteen countries, using multiple measurement methods, resulting 400 values. Four complex but homogenous tested, additionally, microcrystalline cellulose as positive control. Inter-laboratory reported values moderate. Relative standard deviation (RSDR) 7.5 24%, relative range (RR) 31 130%. Systematic biases associated with both within Substrate volatile solids (VS) inoculum origin did make major contributions variability, errors data processing or entry important. There evidence negative manual manometric volumetric methods. Still, much observed variation clearly related any these factors is probably result particular practices that vary even technicians. Based on analysis calculated values, set recommendations developed, considering measurement, processing, validation, reporting. Recommended are: (i) test duration at least 1% net 3 d, (ii) for higher 6%, (iii) mean between 340 395 NmLCH4 gVS−1. Evidence dataset shows following recommendations—in particular, application criteria—can substantially reproducibility, RSDR < 8% RR 25% all substrates. The criterion particularly Results show possible measure very similar different meet recommended criteria, some must changes their To help practice new website detailed, up-to-date guidance established.