Influence of ultrasonic disintegration on efficiency of methane fermentation of Sida hermaphrodita silage

Abstract

The technologies related to the anaerobic decomposition of organic substrates are constantly evolving in terms of increasing the efficiency of biogas production. The use of disintegration methods of organic substrates, which would improve the efficiency of production of gaseous metabolites of anaerobic bacteria without the production of by-products that could interfere with the fermentation process, turns out to be an important strategy. The methane potential of commercially available biodegradable raw materials is huge and their effective use gives the prospect of obtaining an important renewable energy carrier in the form of biogas rich in methane. Ultrasonic disintegration may play a special role in the pre-treatment of substrates subjected to methane fermentation. The pre-treatment based on ultrasonic sonication has a positive effect on the availability of anaerobic compounds released from cellular structures for microorganisms. The research was aimed at determining the influence of ultrasonic sonification on the anaerobic distribution of the organic substrate used, which constituted the mallow silage along with cattle manure with hydration of 90%. The research was carried out using the UP400S Ultrasonic Processor. The disintegration process was applied in two technological variants. The efficiency of biogas and methane production was determined depending on the technological variant used and the time of disintegration. The influence of sonication time on the effectiveness of anaerobic transformation was demonstrated. The highest biogas yield and methane production potential was recorded at 120s. The prolongation of the action time of the ultrasonic field did not significantly increase the biogas production. The use of disintegration of liquid manure as the only medium for the propagation of ultrasonic waves was sufficient to increase the production of gaseous metabolites of anaerobic bacteria. Subjecting the substrate additionally containing mallow silage to the process to sonication did not significantly affect the efficiency of the fermentation process. The percentage of methane in the biogas produced was independent of the pre-treatment conditions of the substrate and was in the range of 66-69%.