Próba wspólfermentacji osadów sciekowych z odpadami miesnymi

An influence of a percentage share of meat waste (as cosubstrate) in co-digestion with sewage sludge on yield and composition of produced biogas was analyzed as well as on a degree of fermentation and physicochemical properties of the sludge. The mechanically thickened waste activated sludge from municipal wastewater treatment plant and waste from a slaughterhouse in Silesian voivodship were used for studies. Studies were carried out for 28 days under static conditions in a sludge digestion system consisting of 12 tight glass bottles of 500 cm3 each, equipped with a kit for biogas collection. Co-digestion was carried out under mesophilic conditions (37 °C). It was demonstrated that an addition of 2-8% share of waste meat into the sewage sludge resulted in an increase of biogas and methane production in comparison with the control sample. The largest increase in the biogas yield (138%) and in the methane content (9%) was obtained at 3% share of waste meat in the mixture. On the other hand, 15% share of waste meat had an adverse effect on the co-digestion process. In comparison with the control sample, lower by about 15% methane content in the biogas and the lowest unit production of biogas was achieved. Also, it was established that an addition of the cosubstrate tested worsen the degree of sludge digestion and adversely affected fi ltration properties of the digested sludge (CST test).