The pyrolysis and combustion of seven samples of sewage sludge were studied
by TG dynamic runs carried out at 15 degreesC min(-1). Two different behav
iors were observed. For some samples, considering the variations of weight
loss versus temperature or time, the combustion thermograms are similar to
those of pyrolysis but with a displacement of the corresponding curves of c
ombustion to temperature intervals less than those of the pyrolysis runs. F
or the other samples, the pyrolysis thermograms coincide with the combustio
n thermograms, except in the last part of the combustion thermogram where a
final decomposition appears as a consequence of the combustion of the char
previously formed. The different behavior can be associated to aerobic sta
bilization of the samples. Some runs were also done with acid-washed sample
s to test the influence of the metal content. (C) 2001 Elsevier Science B.V
. All rights reserved.