Anaerobic digestion of biomass is a commonly used process utilizing troublesome waste for producing biogas. Biogas plants use various types of organic residues including sewage sludge, food industry residues and municipal solid waste. Anaerobic digestion of fish wastes is also possible but is currently not so much used. The amount of fish wastes (by-products and by-catch) depends on fish species, size, season and catch methods. The by-products are generated during fish pretreatment (gutting, heading and filleting). Depending on the efficiency of the production process, even 40-50 percent of total fish catch goes for wastes. Fish wastes have great potential as a source of high valued organic carbon for methane production but also have limitation (high content of ammonia nitrogen). Anaerobic treatment of fish wastes is possible with co-digestion. The main issue for co-digestion process lies in balancing several parameters in the co-substrate mixture: macro- and micronutrients, C:N ratio, pH, toxic compounds, biodegradable organic matter and dry matter. The aim of this work is to find optimal co-digestion substrates to enhance biogas production from fish wastes by determining the most proper ratios of different co-substrates. This work examines the potential for methane production from anaerobic co-digestion fish wastes, grass and sewage sludge (a mixture of primary and secondary). The experiments were carried out in mesophilic temperature with using Automatic Methane Potential Test System (AMTPS II). This equipment automatically measures methane production from batch test. For batch test inoculum is needed and different source for inoculum were used (different SRT). Initial results showed that sludge together with fish intestings produced 0.5 Nm3 CH4/kg VS compared to 0.3 Nm3 CH4/kg VS for grass and fish meat. Sludge and fish as well as grass and fish intestings produced 0.4 Nm3 CH4/kg VS.
Medarbetare: Östen Ekengren
Nyckelord: Anaerobic digestion, biogas, fish wastes, co-digestion, methane production
Författare: Tomczak-Wandzel+ R., Erik Levlin, Östen Ekengren, Baresel C
Publicerad i: IWA 2013 Holistic Sludge Management Conference, May 6-8, 2013 Västerås, Sweden