Resumen

GARCIA-GALINDO, Olivia et al. Evaluation of different sources of organic fecal matter as inoculum for methane production. Tecnol. cienc. agua [online]. 2015, vol.6, n.2, pp.35-49. ISSN 2007-2422.

The use of alternative energies is growing in light of the high costs of fossil fuels and their environmental impact. The objective of this study was to determine the best source of organic fecal matter for use as an initial inoculum in the production of methane, at different temperatures. Batch reactors of 1 000 ml were established in vitro and organic fecal matter and a microbial solution were added as an initial inoculum. A random block design with three repetitions was used. Four sources of organic matter were evaluated -human, cow, pig and goat- as well as the possible double combinations. Each treatment was subjected to temperatures of 3, 37 and 50 °C. A slightly acidic pH created a higher chemical oxygen demand (COD) and therefore a larger production of methane. According to the COD, organic matter from pigs and the combination of pigs and goats were the best treatments (P < 0.05) for the production of methane, primarily at a temperature of 37°C. The removal of organic matter was more efficient and thus methane production was improved during a second scaling phase of the best treatment identified in the in vitro stage, using a UASB (Upflow Anaerobic Sludge Blanket) reactor, with a pH stabilized near neutral and slightly acidic at the end of the experiment.

Palabras llave : Alternative energy; methane gas; biogas; environmental impact.