Cao Xingxing, Chen Shiqin, Liu Yan, Long Guangxi, Xu Y Jun
College of Resources and Environmental Engineering, Guizhou University, Guiyang, China.
Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang, China.
Nat Commun. 2025 Aug 13;16(1):7522. doi: 10.1038/s41467-025-62920-6.
Riverine dissolved carbon (DC) plays a crucial role in global carbon cycle. Yet, the contribution of wastewater to global riverine DC remains unquantified. Here, we quantify the impact of treated and untreated domestic wastewater on dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) loadings at nation and river basin scales. We show that, globally, domestic wastewater discharges ~21.4 Tg DC annually-6.42 Tg DIC and 1.17 Tg DOC from treated, and 9.64 Tg DIC and 4.21 Tg DOC from untreated, collectively accounting for 3.13 ± 0.46% of the global riverine DC export. Contributions are highest in densely populated regions with high treatment capacity. Effluent DC levels are influenced by treatment technology, temperature, precipitation, economic growth and urban development. This underscores a need to incorporate the wastewater derived carbon into global carbon budget assessment, as well as to monitor and reduce carbon in wastewater effluents.
河流溶解碳（DC）在全球碳循环中起着至关重要的作用。然而，废水对全球河流DC的贡献仍未得到量化。在此，我们在国家和流域尺度上量化了经处理和未经处理的生活污水对溶解无机碳（DIC）和溶解有机碳（DOC）负荷的影响。我们表明，在全球范围内，生活污水每年排放约21.4 Tg DC——经处理的污水排放6.42 Tg DIC和1.17 Tg DOC，未经处理的污水排放9.64 Tg DIC和4.21 Tg DOC，合计占全球河流DC输出量的3.13±0.46%。在人口密集且处理能力高的地区，贡献最大。污水DC水平受处理技术、温度、降水、经济增长和城市发展的影响。这凸显了将废水中的碳纳入全球碳预算评估以及监测和减少废水排放中的碳的必要性。
