Multidirectional Fate Path Model to Connect Phosphorus Emissions with Freshwater Eutrophication Potential

Environmental Science & Technology, vol. 58, pp. 11675–11684

Abstract

Excessive anthropogenic phosphorus (P) emissions put constant pressure on aquatic ecosystems. This pressure can be quantified as the freshwater eutrophication potential (FEP) by linking P emissions, P fate in environmental compartments, and the potentially disappeared fraction of species due to increase of P concentrations in freshwater. However, previous fate modeling on global and regional scales is mainly based on the eight-direction algorithm without distinguishing pollution sources. The algorithm fails to characterize the fate paths of point-source emissions via subsurface pipelines and wastewater treatment infrastructure, and exhibits suboptimal performance in accounting for multidirectional paths caused by river bifurcations, especially in flat terrains. Here we aim to improve the fate modeling by incorporating various fate paths and addressing multidirectional scenarios. We also update the P estimates by complementing potential untreated point-source emissions (PSu). The improved method is examined in a rapidly urbanizing area in Taihu Lake Basin, China in 2017 at a spatial resolution of 100 m × 100 m. Results show that the contribution of PSu on FEP (62.6%) is greater than that on P emissions (58.5%). The FEP is more spatially widely distributed with the improved fate modeling, facilitating targeted regulatory strategies tailored to local conditions.

Authors 5

1. Y Zhuang

   State Key Laboratory of Pollution Control and Resource Reuse · Nanjing University

   Affiliation as printed

   State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China

2. Xin Liu

   State Key Laboratory of Pollution Control and Resource Reuse · Nanjing University

   Affiliation as printed

   State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China

3. Jinhui Zhou Aachen Institute of Environmental Sciences (CML)

   Leiden University

   Affiliation as printed

   Institute of Environmental Sciences (CML), Leiden University, 2300 RA Leiden, The Netherlands

4. Sheng Hu

   Chinese Academy of Sciences · Nanjing Institute of Geography and Limnology

   Affiliation as printed

   Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China

5. Zengwei Yuan corresponding

   State Key Laboratory of Pollution Control and Resource Reuse · Nanjing University

   Affiliation as printed

   State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China