The present paper focused on reducing greenhouse gases emissions in wastewater treatment plants operation by application of suitable control strategies. Specifically, the objective is to reduce nitrous oxide emissions during the nitrification process. Incomplete nitrification in the aerobic tanks can lead to an accumulation of nitrite that triggers the nitrous oxide emissions. In order to avoid the peaks of nitrous oxide emissions, this paper proposes a cascade control configuration by manipulating the dissolved oxygen set-points in the aerobic tanks. This control strategy is combined with ammonia cascade control already applied in the literature. This is performed with the objective to take also into account effluent pollutants and operational costs. In addition, other greenhouse gases emissions sources are also evaluated. Results have been obtained by simulation, using a modified version of Benchmark Simulation Model no. 2, which takes into account greenhouse gases emissions. This is called Benchmark Simulation Model no. 2 Gas. The results show that the proposed control strategies are able to reduce by 29.86% of nitrous oxide emissions compared to the default control strategy, while maintaining a satisfactory trade-off between water quality and costs.

中文翻译：

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废水处理厂运行中减少一氧化二氮排放的控制策略

本文的重点是通过应用适当的控制策略来减少废水处理厂运营中的温室气体排放。具体而言，目的是减少硝化过程中的一氧化二氮排放。好氧池中的硝化作用不完全会导致亚硝酸盐积聚，从而触发一氧化二氮排放。为了避免一氧化二氮排放的峰值，本文提出了一种通过控制好氧罐中溶解氧设定点的级联控制配置。该控制策略与文献中已经应用的氨级联控制相结合。这样做的目的是还要考虑废水污染物和运营成本。此外，还评估了其他温室气体排放源。通过使用基准仿真模型（Benchmark Simulation Model）的修改版，通过仿真获得了结果。2，考虑到温室气体的排放。这称为基准仿真模型编号。2气。结果表明，与默认控制策略相比，所提出的控制策略能够减少29.86％的一氧化二氮排放，同时在水质和成本之间保持令人满意的折衷。