Research and Technology Development Department, Japan Sewage Works Agency, Saitama, Japan.
Water Sci Technol. 2010;62(10):2256-62. doi: 10.2166/wst.2010.510.
Reduction of greenhouse gas (GHG) emissions is one of the most important tasks facing municipal WWTPs. Electric power consumption typically accounts for about 90% of the total energy consumption. This study presents a benchmarking analysis of electric power consumption. The specific power consumption (SPC) ranged from 0.44 to 2.07 kWh/m(3) for oxidation ditch plants and from 0.30 to 1.89 kWh/m(3) for conventional activated sludge plants without sludge incineration. Observed differences of the SPC can be attributed to the difference in the scale of plants rather than to different kinds of wastewater treatment processes. It was concluded that economical benefits by centralizing treatment had contributed significantly to the reduction of energy consumption. Further analysis was carried out on the plant that had shown an extremely small SPC value of 0.32 kWh/m(3). In this WWTP, a large amount of digestion gas was generated by anaerobic digestion. In particular, it was used to generate power using phosphoric acid fuel cells to generate approximately 50% of the energy consumed in the plant. It was calculated that this plant had reduced the overall SPC by 0.17 kWh/m(3). The effect of power generation using digestion gas demonstrated clearly the advantage of implementing energy recovery schemes.
减少温室气体（GHG）排放是城市污水处理厂面临的最重要任务之一。电力消耗通常占总能源消耗的约 90%。本研究对电力消耗进行了基准分析。氧化沟工厂的单位电耗（SPC）范围为 0.44 至 2.07 kWh/m³，而没有污泥焚烧的传统活性污泥工厂的 SPC 范围为 0.30 至 1.89 kWh/m³。观察到的 SPC 差异可以归因于工厂规模的差异，而不是不同的污水处理工艺。可以得出结论，通过集中处理实现的经济效益对降低能源消耗做出了重大贡献。对表现出 0.32 kWh/m³ 极低 SPC 值的工厂进行了进一步分析。在这个污水处理厂，大量的消化气通过厌氧消化产生。特别是，它被用于使用磷酸燃料电池发电，以产生工厂消耗的约 50%的能源。据计算，该工厂通过降低整体 SPC 来实现 0.17 kWh/m³ 的节能效果。消化气发电的效果清楚地表明了实施能源回收方案的优势。
