Stormwater volume reduction and water quality improvement by bioretention: Potentials and challenges for water security in a subtropical catchment

Author(s)

de Macedo, Marina Batalini ^[1] ; Ferreira do Lago, Cesar Ambrogi ^[1] ; Mendiondo, Eduardo Mario ^[2]

Affiliation

^[1] Univ Sao Paulo, Hydraul Engn & Sanitat, Av Trabalhador Saocarlense 400 CP 359, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Av Trabalhador Saocarlense 400 CP 359, BR-13566590 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Science of The Total Environment; v. 647, p. 923-931, JAN 10 2019.
• Web of Science Citations: 9

Abstract

Climate change scenarios tend to intensify extreme rainfall events and drought in Brazil threatening urban water security. Low Impact Development (LID) practices are decentralized alternatives for flood mitigation and prevention. Recently, their potential has increasingly been studied in terms of stormwater harvesting. However, there is still a lack of knowledge about their potentialities in subtropical climate regions. Therefore, this study evaluated the behavior of a bioretention cell in a Brazilian city, during the dry period, which is critical in terms of pollutant accumulation and water availability. In addition to the runoff reduction and pollutant removal efficiency, this paper analyzed the potential for water reuse in terms of the stored volume and water quality guidelines. The results obtained show an average runoff retention efficiency of 70%. Considering only the water availability aspects, the potential stored runoff could be reused for non-potable purposes, reducing the water demand in the catchment by at least half during the dry season. On the other hand, the bioretention presented two different conditions for pollutant removal: Condition A - the concentration values are within the recommended limits for water reuse. The parameters found in this condition were NO3, NO2, Zn, Mn, Cu, Cr; Condition B - the pollutant concentrations are above the guideline limits for water reuse and cannot be directly used for different purposes. The parameters found in this condition were Fe, Pb, Ni, Cd and color. Considering water reuse, an additional treatment is required for parameters in this second condition. Further studies should evaluate the design aspects that can allow collection of LIDs effluent, additional treatment if necessary, and reuse in the catchment. (c) 2018 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/50848-9 - INCT 2014: INCT for Climate Change
• Grantee: Jose Antonio Marengo Orsini
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 15/20979-7 - Optimizing bioretention operation and maintenance of stormwater treatment practices in subtropical climate
• Grantee: Marina Batalini de Macedo
• Support Opportunities: Scholarships in Brazil - Master