Peterse Ida F, Hendriks Lisanne, Weideveld Stefan T J, Smolders Alfons J P, Lamers Leon P M, Lücker Sebastian, Veraart Annelies J
Department of Microbiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, P.O. Box 9010, 6500 GL Nijmegen, the Netherlands; Department of Ecology, Radboud Institute for Biological and Environmental Sciences, Radboud University, P.O. Box 9010, 6500 GL Nijmegen, the Netherlands.
Department of Ecology, Radboud Institute for Biological and Environmental Sciences, Radboud University, P.O. Box 9010, 6500 GL Nijmegen, the Netherlands.
Sci Total Environ. 2024 Nov 15;951:175797. doi: 10.1016/j.scitotenv.2024.175797. Epub 2024 Aug 26.
Rivers are well-known sources of the greenhouse gasses (GHG) carbon dioxide (CO), methane (CH) and nitrous oxide (NO). These emissions from rivers can increase because of anthropogenic activities, such as agricultural fertilizer input or the discharge of treated wastewater, as these often contain elevated nutrient concentrations. Yet, the specific effects of wastewater effluent discharge on river GHG emissions remain poorly understood. Here, we studied two lowland rivers which both receive municipal wastewater effluent: river Linge and river Kromme Rijn. Dissolved concentrations and fluxes of CH, NO and CO were measured upstream, downstream and at discharge locations, alongside water column properties and sediment composition. Microbial communities in the sediment and water column were analysed using 16S rRNA gene sequencing. In general, observed GHG emissions from Linge and Kromme Rijn were comparable to eutrophic rivers in urban and agricultural environments. CO emissions peaked at most discharge locations, likely resulting from dissolved CO present in the effluent. CH emission was highest 2 km downstream, suggesting biological production by methanogenic activity stimulated by the effluents' carbon and nutrient supply. Dissolved NO concentrations were strongly related to NO content of the water column which points towards incomplete riverine denitrification. Notably, methanogenic archaea were more abundant downstream of effluent discharge locations. However, overall microbial community composition remained relatively unaffected in both rivers. In conclusion, we demonstrate a clear link between wastewater effluent discharge and enhanced downstream GHG emission of two rivers. Mitigating the impact of wastewater effluent on receiving rivers will be crucial to reduce riverine GHG contributions.
河流是温室气体（GHG）二氧化碳（CO）、甲烷（CH）和一氧化二氮（NO）的著名排放源。由于农业肥料投入或经处理废水排放等人为活动，河流的这些排放可能会增加，因为这些活动通常含有较高的养分浓度。然而，废水排放对河流温室气体排放的具体影响仍知之甚少。在此，我们研究了两条均接收城市废水排放的低地河流：林格河和克罗默莱茵河。在河流上游、下游和排放地点测量了CH、NO和CO的溶解浓度及通量，同时测量了水柱特性和沉积物成分。利用16S rRNA基因测序分析了沉积物和水柱中的微生物群落。总体而言，林格河和克罗默莱茵河观测到的温室气体排放与城市和农业环境中的富营养化河流相当。大多数排放地点的CO排放达到峰值，这可能是由于废水中存在溶解的CO。CH排放在下游2公里处最高，这表明废水的碳和养分供应刺激了产甲烷活动的生物生产。溶解的NO浓度与水柱中的NO含量密切相关，这表明河流反硝化作用不完全。值得注意的是，产甲烷古菌在废水排放地点下游更为丰富。然而，两条河流的整体微生物群落组成相对未受影响。总之，我们证明了废水排放与两条河流下游温室气体排放增加之间存在明确联系。减轻废水排放对受纳河流的影响对于减少河流温室气体排放至关重要。
