Estabilización del lodo secundario de una PTAR por co-digestión anaerobia

Abstract:

The aim of the present study was to establish an alternative for the disposal of the secondary sludges generated at the WWTP at the Universidad de las Américas. The stabilization of the sludges was carried out by means of anaerobic co – digestion with pig and cattle manures, at different temperatures systems, such as mesophilic (35 grades centigrade) and thermophilic (55 grades centigrade), and with an application of a thermal pre – treatment prior to its digestion process (170 grades centigrade, 90 minutes). Throughout the study, several physical – chemical parameters, such as alkalinity, pH, COD and BOD 5 were analyzed and interpreted as process stability and efficiency indicators. The content of volatile solids and fecal coliforms were also evaluated in order to verify their compliance with the regulation criteria used (USEPA, 2012). Finally, the methane content in the biogas of the diverse substrate was determinated. The sludges stabilization was achieved through mesophilic and thermophilic anaerobic co – digestion of pig manure. Class “A” biosolids were obtained and the biogas of these substrates had a final methane content between 55.65 and 60.5 porcent. In general, anaerobic co – digestion of pig and cattle manure increased process stability and biogas methane content as well as substrate biodegradability and organic matter removal rates. On the other hand, mesophilic anaerobic digestion proved to be a more stable system compared to a thermophilic system and the use of a thermal pre – treatment prior the anaerobic digestion process proved to have distinct effects on the substrates. In conclusion, anaerobic co - digestion of pig manure enhanced the stabilization process of the secondary sludge of a WWTP both in mesophilic as well as in thermophilic regimes.

Año de publicación:

2018

Keywords:

• DEGRADACIÓN BIOLÓGICA
• Biodegradación
• LODOS RESIDUALES

Fuente:

rraae