Abstract：
Foaming pretreatment has been proven effective in promoting sludge drying, however, the variation in sludge properties significantly influences the foaming efficiency. Inspired by foam stabilizer of solid particles, Camellia oleifera shells (COS) was screened out from various biomasses as an additive incorporated with the CaO for promoting the sludge foaming. For the introduction of COS, this study analyzed the drying behaviors of foamed sludge, quantified the surface cracks information, characterized the combustion performance, and evaluated the energy consumption. The results indicated that 46.72-50.10% of time could be saved in foaming the sludge to 0.70 g/mL by addition of 3.0 wt% COS. Compared with the original sludge (OS), the 0.70 g/mL foamed sludge saved 47.43% of time for sludge drying at 80 °C, and this value further increased to 53.14% with 3.0 wt% COS addition. Combining the multifractal spectra and drying kinetics analysis, the foaming promoted the formation of complex surface cracks in the warm-up period, while COS further improved the complexity of cracks in the constant rate period, and the shrinkage of isolated sludge blocks in the falling rate period, thus enhanced the moisture diffusion and heat transfer. Furthermore, the appropriate porous structure and additional volatile matters promoted the combustion performance. The 0.90 g/mL foamed sludge with COS presented the lowest activation energy of 180.362 kJ/mol in combustion. Overall, compared with OS, the 0.70 g/mL foamed sludge with COS saved 40.65% energy consumption during the foaming, drying and combustion processes, providing an energy-efficient solution for the sludge treatment and disposal.
摘要：
发泡预处理已被证明有效促进污泥干燥，然而,污泥性质的变化显著影响发泡效率。受固体颗粒泡沫稳定剂的启发，从各种生物质中筛选出油茶壳（COS），作为与CaO混合以促进污泥起泡的添加剂。关于COS的介绍，本研究分析了泡沫污泥的干燥行为，量化表面裂纹信息，以燃烧性能为特征，并评估了能源消耗。结果表明，通过添加3.0wt％的COS，使污泥起泡至0.70g/mL可以节省46.72-50.10％的时间。与原始污泥（OS）相比，0.70g/mL泡沫污泥在80°C下可节省47.43％的污泥干燥时间，并且该值在添加3.0wt%COS的情况下进一步增加到53.14%。结合多重分形光谱和干燥动力学分析,发泡促进了预热期复杂表面裂纹的形成，而COS进一步提高了恒定速率周期内裂纹的复杂性，以及孤立污泥块在下降速率期的收缩，从而增强了水分的扩散和传热。此外，适当的多孔结构和额外的挥发性物质促进了燃烧性能。含COS的0.90g/mL泡沫污泥在燃烧中的活化能最低为180.362kJ/mol。总的来说,与操作系统相比，0.70g/mL含COS的泡沫污泥在发泡过程中节省了40.65%的能耗，干燥和燃烧过程，为污泥处理和处置提供节能解决方案。
