Department of Chemical Engineering, University of Barcelona, Barcelona, Spain.
Water Res. 2012 Dec 1;46(19):6218-27. doi: 10.1016/j.watres.2012.07.035. Epub 2012 Aug 1.
The anaerobic digestion of raw sewage sludge was evaluated in terms of process efficiency and sludge hygienization. Four different scenarios were analyzed, i.e. mesophilic anaerobic digestion, thermophilic anaerobic digestion and mesophilic anaerobic digestion followed by a 60 °C or by an 80 °C hygienization treatment. Digester performance (organic matter removal, process stability and biogas yield) and the hygienization efficiency (reduction of Escherichia coli, somatic coliphages and F-specific RNA phages) were the main examined factors. Moreover, a preliminary economical feasibility study of each option was carried out throughout an energy balance (heat and electricity). The obtained results showed that both thermophilic anaerobic digestion and mesophilic anaerobic digestion followed by a hygienization step were able to produce an effluent sludge that fulfills the American and the European legislation for land application. However, higher removal efficiencies of indicators were obtained when a hygienization post-treatment was present. Regarding the energy balance, it should be noted that all scenarios have a significant energy surplus. Particularly, positive heat balances will be obtained for the thermophilic anaerobic digestion and for the mesophilic anaerobic digestion followed by 60 °C hygienization post-treatment if an additional fresh-sludge/digested sludge heat exchanger is installed for energy recovery.
采用过程效率和污泥卫生学的角度评估了未经处理的污水污泥的厌氧消化。分析了四种不同情况，即中温厌氧消化、高温厌氧消化以及中温厌氧消化后进行 60°C 或 80°C 的卫生处理。主要考察因素为消化器性能（有机物去除率、过程稳定性和沼气产量）和卫生处理效率（大肠杆菌、肠道噬菌体和 F 特异性 RNA 噬菌体的减少）。此外，通过能量平衡（热和电）对每种方案进行了初步的经济可行性研究。研究结果表明，高温厌氧消化和中温厌氧消化后进行卫生处理都能产生符合美国和欧洲土地应用法规的污泥。然而，存在卫生处理后处理时，可以获得更高的指标去除效率。关于能量平衡，应注意到所有方案都有显著的能量盈余。特别是，如果为能量回收安装了新鲜污泥/消化污泥热交换器，则高温厌氧消化和中温厌氧消化后 60°C 卫生处理后将获得正的热平衡。
