THE DEVELOPMENT OF A NEW METHODOLOGY FOR THE ASSESSMENT OF SPECIFIC METHANOGENIC ACTIVITY

The measurement of the potential of anaerobic sludges to convert soluble substrate into CH4 and CO2 has mainly been carried out in two different ways: firstly, by the so called "specific methanogenic activity test" (SMA test), through the methane production rate and, secondly, by the assessment of the coenzyme F420 contents in the sludge. However, a very poor correlation was found between the measurements of F420 concentration and the SMA test carried out using acetate as substrate, Dolfing and Mulder (Appl. envir. Microbiol. 49, 1142-1145, 1985). Therefore, improvements of the SMA test through a methodology that could easily be controlled and standardized, would certainly lead to more reliable results. This paper presents a new methodology for the SMA test, which fits the major requirements necessary for an accurate performance of the test. Several experiments utilizing different sludges were carried out, and the results were very consistent leading to the conclusion that this method can be applied to any type of anaerobic sludge and can be easily standardized. © 1990.