Abstract The impacts of hybrid microwave-oxidative (MW-H2O2) feed sludge pretreatment on performance efficiency of conventional single-stage and a novel two-stage semi-continuous anaerobic digestion of mixed waste activated sludge were studied to enhance biogas production and digestate quality. Untreated two-stage anaerobic digestion (thermophilic followed by mesophilic) achieved 76.4 ml/gTCOD methane yield compared to 40.4 ml/gTCOD achieved through conventional mesophilic anaerobic digestion, with an increase in methane percentage. Application of hybrid (MW-H2O2) sludge pretreatment in the two-stage digestion enhanced initial sludge hydrolysis/solubilisation and consequently achieved 143.4 ml/gTCOD methane yield. Also, the highest methane percentage of 71 % was achieved during peak methanogenesis stage in this process. The synergetic effects of hybrid pretreatment were also confirmed by the higher release of extracellular polymeric substances. Oxidative stress exerted by the pretreatment resulted in the accumulation of superoxide radicals in the initial thermophilic phase; followed by increased sludge activity and biomethanation in the later phase of two-stage digestion. Hybrid feed sludge pretreatment in the two-stage system achieved a 73 % volatile solids reduction and more than 90 % reduction of faecal coliform. The various kinetic model parameters were determined by the application of the modified Gompertz model. These results illustrate that a novel semi-continuous two-stage anaerobic digester with hybrid feed sludge pretreatment improved sludge hydrolysis, sludge solubilisation, biogas production, sludge stabilization and reduces sludge retention time, and also achieves “class-A” biosolids by significant pathogen destruction.

中文翻译：

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混合（微波-H2O2）进料污泥预处理对真实混合污水污泥单级和两级厌氧消化效率的影响

摘要 研究了混合微波氧化 (MW-H2O2) 进料污泥预处理对传统单级和新型两级半连续厌氧混合废物活性污泥的性能效率的影响，以提高沼气产量和沼气质量。未经处理的两阶段厌氧消化（先高温后中温）实现了 76.4 ml/gTCOD 的甲烷产量，而通过传统的中温厌氧消化实现的 40.4 ml/gTCOD 甲烷产量增加，甲烷百分比增加。混合 (MW-H2O2) 污泥预处理在两阶段消化中的应用增强了初始污泥水解/增溶，从而实现了 143.4 ml/gTCOD 甲烷产量。此外，在该过程的产甲烷高峰阶段达到了 71% 的最高甲烷百分比。混合预处理的协同作用也通过细胞外聚合物的更高释放得到证实。预处理施加的氧化应激导致初始高温相中超氧自由基的积累；其次是在两阶段消化的后期阶段增加污泥活性和生物甲烷化。两级系统中的混合进料污泥预处理实现了 73% 的挥发性固体减少和超过 90% 的粪便大肠菌减少。各种动力学模型参数通过应用修正的 Gompertz 模型确定。这些结果表明，具有混合进料污泥预处理的新型半连续两级厌氧消化器改善了污泥水解、污泥增溶、沼气生产、污泥稳定并减少了污泥停留时间，