Department of Animal Sciences and Aquatic Ecology, Ghent University, Ghent, Belgium.
Department of Animal Sciences and Aquatic Ecology, Ghent University, Ghent, Belgium; PROMAS, Universidad de Cuenca, Cuenca, Ecuador; BIOMATH, Department of Data Analysis and Mathematical Modelling, Ghent University, Ghent, Belgium.
Water Res. 2021 Apr 1;193:116858. doi: 10.1016/j.watres.2021.116858. Epub 2021 Jan 20.
Due to regular influx of organic matter and nutrients, waste stabilization ponds (WSPs) can release considerable quantities of greenhouse gases (GHGs). To investigate the spatiotemporal variations of GHG emissions from WSPs with a focus on the effects of sludge accumulation and distribution, we conducted a bathymetry survey and two sampling campaigns in Ucubamba WSP (Cuenca, Ecuador). The results indicated that spatial variation of GHG emissions was strongly dependent on sludge distribution. Thick sludge layers in aerated ponds and facultative ponds caused substantial CO and CH emissions which accounted for 21.3% and 78.7% of the total emissions from the plant. Conversely, the prevalence of anoxic conditions stimulated the NO consumption via complete denitrification leading to a net uptake from the atmosphere, i.e. up to 1.4±0.2 mg-N m d. Double emission rates of CO were found in the facultative and maturation ponds during the day compared to night-time emissions, indicating the important role of algal respiration, while no diel variation of the CH and NO emissions was found. Despite the uptake of NO, the total GHG emissions of the WSP was higher than constructed wetlands and conventional centralized wastewater treatment facilities. Hence, it is recommended that sludge management with proper desludging regulation should be included as an important mitigation measure to reduce the carbon footprint of pond treatment facilities.
由于有机物质和养分的不断流入，污水稳定塘（WSP）会释放大量温室气体（GHG）。为了研究 WSP 温室气体排放的时空变化，重点关注污泥积累和分布的影响，我们在厄瓜多尔昆卡的 Ucubamba WSP 进行了地形测量和两次采样活动。结果表明，温室气体排放的空间变化强烈依赖于污泥的分布。曝气池和兼性池中的厚污泥层导致大量的 CO 和 CH 排放，分别占工厂总排放量的 21.3%和 78.7%。相反，缺氧条件的盛行通过完全反硝化刺激了 NO 的消耗，导致从大气中净吸收，即高达 1.4±0.2mg-N m d。与夜间排放相比，兼性和成熟池中白天的 CO 排放速率是其两倍，这表明藻类呼吸的重要作用，而 CH 和 NO 排放没有昼夜变化。尽管吸收了 NO，但 WSP 的总温室气体排放量仍高于人工湿地和传统集中式污水处理设施。因此，建议将适当的清淤管理纳入污泥管理，作为减少池塘处理设施碳足迹的重要缓解措施。
