Abstract

ATENODORO-ALONSO, J. et al. The enhanced anaerobic degradability and kinetic parameters of pathogenic inactivation of wastewater sludge using pre- and post-thermal treatments part 2. Rev. Mex. Ing. Quím [online]. 2015, vol.14, n.2, pp.311-319. ISSN 1665-2738.

In Mexico, wastewater sludge is characterized by high concentrations of organic compounds and pathogenic microorganisms. This study proposes the development and comparison of the anaerobic digestion enhanced with thermal pre-treatment denominated Pre-anaerobic digestion (Pre-AD) and with thermal post-treatment denominated Post-anaerobic digestion (Post-AD) processes for treating wastewater sludge. Additionally, the results from a kinetic model that was developed for thermal inactivation were used to describe the inactivation of faecal coliforms, Salmonella spp. and helminth ova during the thermal treatment stages. In the Post-AD operational batch test, it was determined that a period of 27 d was necessary to reduce the volatile solids (VS) by 38% at an organic loading rate of 0.65 kg VS m^-3d^-1. When the Pre-AD process was evaluated, 13 d of treatment was sufficient for meeting the stabilisation criteria at an organic loading rate (ORL) of 1.25 kg VS m^-3d^-1 in the batch test. In a semicontinuous operation tests, the Pre-AD process could be operated at an OLR of 3 kg VS m^-3d^-1, while the Post-AD process could only be operated at an OLR of 1.5 kg VS m^-3 d^-1. The bacteria and helminth ova were inactivated at 70°C for 1 h and 80°C for 2 h, respectively.

Keywords : anaerobic-thermal sludge digestion; thermal inactivation; thermal-anaerobic sludge digestion; pathogenic thermal inactivation; kinetic parameters.

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