Adjusting wastewater treatment effluent standards to protect the receiving waters: the case of low-flow rivers in centra
- PDF / 1,894,016 Bytes
- 17 Pages / 595.276 x 790.866 pts Page_size
- 7 Downloads / 155 Views
ORIGINAL ARTICLE
Adjusting wastewater treatment effluent standards to protect the receiving waters: the case of low‑flow rivers in central Spain Antonio Bolinches1,2 · Lucia De Stefano1,2 · Javier Paredes‑Arquiola3 Received: 17 May 2019 / Accepted: 9 September 2020 / Published online: 23 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Freshwater quality is deteriorating worldwide. In populated areas, urban pollution is the main pressure on surface continental waters, but intensive wastewater treatment is costly. Setting standards for treatment of wastewater before discharge is a major policy instrument for water authorities, balancing environmental gains and operational costs. Discharge permits usually define concentration limits at the discharge point of the plant effluent. This approach, however, may not guarantee the good status of the receiving waters. Discharge permits should be directly linked to pollutant concentration in the river. Our paper develops an approach to adaptively adjust discharge permits and applies it to Madrid and the Manzanares river, a city of more than 3 million inhabitants discharging its treated wastewater to a stream having less than 2 m 3 s−1 average flow. −1 −1 Stricter limits to 5-day biological oxygen demand (11 mg O2 L ), ammonium (0.5 mg N-NH4 L ), nitrate (5.9 mg N-NO3 L−1), and phosphate (0.17 mg P-PO4 L−1) at plant effluent are required to meet the river environmental objectives. The results can be generalized to assess wastewater management decisions in other geographical areas. Keywords Wastewater · Water framework directive · Water quality · Tagus basin
Introduction Freshwater quality is degrading worldwide due to increased human pressure (United Nations Environment Program 2015). Among the stressors, wastewater treatment plant (WWTP) effluents are a major contributor of pollutants, especially in densely populated areas (Carey and Migliaccio 2009). Considerable research attention has been devoted to the quality of water streams in urban environments. Apart from the changes in hydrology and geomorphology, Paul and Meyer (2001) identified a general increase in the concentration nutrients, metals, pesticides, and other contaminants in urban rivers, associated with city growth. Similar conclusions were drawn by McGrane (2016), who further acknowledged that our understanding of dynamics of pollutants * Antonio Bolinches [email protected] 1
Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain
2
Water Observatory, Botín Foundation, Madrid, Spain
3
Research Institute of Water and Environmental Engineering, Universitat Politècnica de València, Camí de Vera, s/n, 46022 València, Spain
remain limited and a priority area for continued research. Nevertheless, an empirical study on the world’s largest cities (Duh et al. 2008) found that urban growth is not necessarily linked to increasing pollution, since technological advances and environmental policy can mitigate th
Data Loading...
