Mucha Zbigniew, Mikosz Jerzy
a Institute of Water Supply and Environmental Protection, Cracow University of Technology , Cracow , Poland.
Environ Technol. 2016 Oct;37(19):2516-23. doi: 10.1080/09593330.2016.1153157. Epub 2016 Mar 10.
Many municipal wastewater treatment plants are retrofitted with membrane filtration that replaces secondary clarification. Such a solution saves space and improves overall treatment efficiency but at the cost of increased energy consumption and reduced potential for energy recovery from sewage sludge. Thus, the plant takes a step back from reaching energy self-sufficiency. In the presented case study, two alternative upgrade options were simulated for a medium-size municipal wastewater treatment plant in Poland: the first one assumed optimization of the existing bioreactor, and the other - installation of microfiltration membrane units inside the bioreactor. In both cases, anaerobic digestion of waste sludge with biogas utilization is planned. The results have shown that while under both upgrade options, the plant's capacity can be effectively increased by approximately 50%, their effects on the plant's energy balance will be very different. Although the installation of membrane modules accompanied by the construction of anaerobic digestion tanks improves the plant's energy balance, it will remain negative. The option of optimizing the existing biological treatment system produces a positive energy balance with more energy produced from biogas than consumed. Thus, the plant is able to approach energy self-sufficiency. It has been concluded that retrofitting the plants with membrane filtration is not always the best option from the energy balance point of view and it should be preceded with a detailed analysis on a case-by-case basis.
许多城市污水处理厂都进行了改造，采用膜过滤取代二次澄清。这种解决方案节省了空间，提高了整体处理效率，但代价是能源消耗增加，以及从污水污泥中回收能源的潜力降低。因此，该工厂在实现能源自给自足方面后退了一步。在本案例研究中，对波兰一家中型城市污水处理厂模拟了两种替代升级方案：第一种方案是对现有生物反应器进行优化，另一种方案是在生物反应器内部安装微滤膜单元。在这两种情况下，都计划对剩余污泥进行厌氧消化并利用沼气。结果表明，虽然在两种升级方案下，工厂的处理能力都能有效提高约50%，但它们对工厂能量平衡的影响将大不相同。虽然安装膜组件并建设厌氧消化池可改善工厂的能量平衡，但仍将是负平衡。优化现有生物处理系统的方案产生了正能量平衡，沼气产生的能量多于消耗的能量。因此，该工厂能够接近能源自给自足。得出的结论是，从能量平衡的角度来看，用膜过滤对工厂进行改造并不总是最佳选择，应该在逐个案例的基础上进行详细分析。
