Enzymatic estimation of biosolids stability in aerobic digestion systems

From the results, it may be concluded that the traditional physicochemical and microbiological parameters present a series of problems, which detract from their usefulness. The enzymatic parameters, dehydrogenase activity (primary metabolism) and esterase activity (secondary metabolism) are better able to characterise the process; and the quotient between these two variables may be used to estimate the degree of endogenesis and, consequently, the degree of stability of the aerobic sludge digestion. In addition, these techniques are swift and simple to employ.