A review on physicochemical and microbiological contamination of roof-harvested rainwater in urban areas A.S. Sánchez a,⇑ , E. Cohim b,1 , R.A. Kalid c,2 a Federal University of Bahia, Escola Politécnica, Rua Aristides Novis, n° 2, 6° Andar – Federação, Salvador-BA CEP 40.210-630, Brazil b State University of Feira de Santana, Av. Transnordestina, S/N – Novo Horizonte, Módulo III, Feira de Santana-BA CEP 44036-900, Brazil c Federal University of South Bahia Campus Jorge Amado, Rua Itabuna, s/n, Rod. Ilhéus-Vitória da Conquista, km 39, BR 415, Ferradas, Itabuna-BA CEP 45613-204, Brazil article info Article history: Received 15 January 2015 Received in revised form 16 March 2015 Accepted 7 April 2015 Available online xxxx Keywords: Rainwater harvesting Atmospheric deposition Wet deposition Rainwater contamination Runoff abstract This work proposes to consider the quality of roof-collected rainwater as the sum of three main stages. In the first one, rainfall washes out the urban atmosphere and scavenges con- taminants from aerosols, gases and thin volatile particles. The second stage refers to the catchment, in which occurs contamination due to the wash-off of particles settled on the roof’s surface as well as the scavenging of roofing materials. The third stage refers to the first-flush, storage and plumbing system. In each stage, different processes take place and add specific contaminants to the initial precipitation. Only in the third stage, after the discard of the high-polluted initial rainwater, some physical processes (sedimentation and pH increase) can also improve the quality of the rainwater harvest. With this approach, it is offered a clear view of the overall contamination processes that take place in a rainwa- ter harvesting system. The most common microbiological and physicochemical contaminants that can be found in rainwater harvesting system were regarded, together with the eventual presence of waterborne pathogens and emerging chemical contaminants, according to an extensive review of 172 previous scientific and technical works. Ó 2015 Elsevier B.V. All rights reserved. Contents 1. Introduction ............................................................................................. 00 2. Rainwater contamination due to atmospheric deposition in urban environments ..................................... 00 2.1. Atmospheric deposition processes ...................................................................... 00 2.2. Nitrogen ........................................................................................... 00 2.3. Phosphorus ........................................................................................ 00 2.4. Other ions ......................................................................................... 00 2.5. Acidity ............................................................................................ 00 2.6. Heavy metals ....................................................................................... 00 2.7. Emerging contaminants .............................................................................. 00 http://dx.doi.org/10.1016/j.swaqe.2015.04.002 2212-6139/Ó 2015 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +55 71 32 839 800; fax: +55 71 32 839 801. E-mail addresses: sanchezbahia@gmail.com (A.S. Sánchez), edcohim@gmail.com (E. Cohim), kalid@ufba.br (R.A. Kalid). 1 Tel.: +55 75 31 618 059. 2 Tel.: +55 73 36 163 180. Sustainability of Water Quality and Ecology xxx (2015) xxx–xxx Contents lists available at ScienceDirect Sustainability of Water Quality and Ecology journal homepage: www.elsevier.com/locate/swaqe Please cite this article in press as: Sánchez, A.S., et al. A review on physicochemical and microbiological contamination of roof-harvested rainwater in urban areas. Sustain. Water Qual. Ecol (2015), http://dx.doi.org/10.1016/j.swaqe.2015.04.002