Quantity and Quality of Biogas Produced from the Poultry Sludge Optimized by Filamentous Fungi

Abstract

One of the methods for recovery and utilization of waste products from the poultry industry is to subject them to the methane fermentation process in the biogas plant. These are waste with a high content of fatty compounds and proteins, including keratin. Their specificity is characterized by rapid possibility of spoilage, rancidity and problems of further management. These wastes are characterized by varying degrees of complexity, thus their use as a raw material for the biogas fermenter should be preceded by a pre-treatment. An example of waste generated in poultry processing is biological sludge. Optimizing this material with highly enzymatic fungi could accelerate the degradation of the organic matter contained and, as a result, increase the energy efficiency of this type of waste. Quantitative and qualitative parameters of biogas produced from biological sludge processed by isolated filamentous fungi with high metabolic potential were determined. Laboratory tests were based on the modified methodology included in the standards DIN 38414-S8 and VDI 4630. Based on the results obtained, it was found that the pre-optimization of biological sludge by fungal strains with different metabolic potential, influences on the yield of biogas production, including methane. There was an increase in the biogas yield from the biological sludge processed by the mixed fungal consortium (by 20 %) and the strain marked as F1 (by 14 %) as compared to the non-inoculated material, which was also reflected in the amount of methane produced in the case of the mixed fungal consortium (by 28 %) and the strain marked as F1 (by 12 %).