Differences in soluble COD and ammonium when applying ultrasound to primary, secondary and mixed sludge

摘要: Ultrasound treatment is often applied to enhance the anaerobic digestion of sludge. Optimal conditions for organic matter solubilisation primary, secondary and mixed sludge were assessed by implementing ultrasound disruption at different specific energies (from 3,500 21,000 kJ/kgTS). The variation in soluble chemical oxygen demand (sCOD) ammonium nitrogen (NH4+-N) was monitored following treatment, after a subsequent fermentation (24 h, 37 °C). effect clearly more pronounced than other types Relatively minimal values solubility found when applying depending on (3,500–7,000 kJ/kgTS primary 10,500–14,000 sludge). This value not so noticeable addition inoculum required order perform fermentation. After this final stage, no general pattern terms sCOD observed. Increases decreases conditioned coverage irradiation; NH4+-N increased notably during