With stricter regulations and concerns over sustainability, combustion can be a beneficial handling method as dried sludge can be used as an energy source. Anaerobic digestion of sludge also provides energy in the form of biogas without the need for sludge drying. Yet, anaerobic digestion reduces the calorific value (CV) of sludge. In this study, the effect of anaerobic digestion (with or without ultrasound pretreatment) on the fuel properties of sludge were examined through laboratory experiments. Additionally, a number of sludge management strategies were evaluated to maximize energy gain. Temporal changes in fuel properties of sludge were tracked during digestion. Results showed that sonication provided a 3.4-fold increase in soluble COD, 15% increase in biogas production and 32% increase in methane production, while the CV of sludge reduced from 14.7 kJ/g to 10 kJ/g. Energy balances for a number of sludge management process trains showed that the optimal method was the combination of thickening, dewatering, thermal drying and combustion. Addition of digestion and ultrasound pretreatment to this scenario reduced the energy gained from sludge. Yet, high ambient temperatures impacted results such that the net energy gain by the scenario including digestion and combustion was close to that of combustion only.

有了更严格的规定和对可持续性的关注，燃烧可以成为一种有益的处理方法，因为干污泥可以用作能源。污泥的厌氧消化还可以以沼气的形式提供能量，而无需进行污泥干燥。然而，厌氧消化降低了污泥的热值（CV）。在这项研究中，厌氧消化（有或没有超声波预处理）对污泥燃料性质的影响通过实验室实验进行了检验。此外，还评估了许多污泥管理策略，以最大程度地提高能量获取。消化过程中跟踪了污泥燃料特性的时间变化。结果表明，超声处理可溶的COD增加3.4倍，沼气产量增加15％，甲烷产量增加32％，而污泥的CV从14.7 kJ / g降低到10 kJ / g。许多污泥管理流程的能量平衡表明，最佳方法是增稠，脱水，热干燥和燃烧相结合。在这种情况下增加消化和超声预处理可以减少污泥获得的能量。然而，高环境温度影响了结果，因此包括消化和燃烧在内的情景所获得的净能量仅接近于燃烧。