The effect of acid treatment on the pyrolysis behavior of sewage sludges

One sewage sludge (SLA) from Ávila region (Spain) was selected and used as raw material in order to study the influence of acid treatment on the pyrolysis behavior of sewage sludges. SLA was heat treated with acid solutions at pH 1 and pH 2 leading to SLA-1 and SLA-2, respectively. Characterization of samples has showed that acid treatment leads to metals removal and modifications in the organic matter composition of sewage sludge. Pyrolysis of three samples showed that SLA and SLA-1 have a similar pyrolysis behavior whereas SLA-2 shows a slightly extended temperature interval for pyrolysis, beginning at lower temperature and finishing at higher temperatures.