ORIGINAL PAPER Bank filtration in a coastal lake in South Brazil: water quality, natural organic matter (NOM) and redox conditions study L. G. Romero-Esquivel 1 • T. Grischek 2 • B. S. Pizzolatti 3 • R. I. Mondardo 4 • M. L. Sens 4 Received: 22 January 2017 / Accepted: 20 June 2017 Ó Springer-Verlag GmbH Germany 2017 Abstract Bank filtration (BF) was evaluated as new treatment or pre-treatment option for drinking water pro- duction in Brazil. General water quality parameters, nat- ural organic matter (NOM) and redox conditions were evaluated in Lagoa do Peri, a costal lake in Santa Catarina, South Brazil. Studies in two periods at two bank filtrations well systems, in a 45-m-length column and in a test filter laboratory scale set-up, were performed. The well systems and the column showed the removal of turbidity and colour from around 7 NTU and 65 Pt–Co, respectively, to below the local regulations (1 NTU and 15 Pt–Co units). Both systems demonstrated a good removal of NOM and trihalomethanes (THM) precursors with a preference removal of THM precursors. The NOM and THM pre- cursor removal in the large column and the test filter were effectively modelled. In both cases, an easily degradable organic matter fraction was modelled; in the large column a moderate degradable fraction was identified as well. The first fraction was removed during the first days of travel time of the bank filtrate. A change to reduced redox conditions was observed in the large column experiment. The same happened in the wells system, showing the dissolution of iron, manganese and sulphide in the bank filtrate. This was the principal drawback of BF comparing with the already existing direct filtration (DF) treatment plant. BF performed slightly better in THM precursor removal (52%) than DF (42%). Therefore, BF could be a pre-treatment for the DF treatment system, and the exist- ing facility could be adapted for iron and manganese removal. Keywords Bank filtration  Coastal lake  NOM removal  Redox conditions  Water treatment List of symbol c T Total concentration c at the time t (mg C/L) c 0i Concentration of the degradable portion i (mg C/L) c 0T Concentration of the residual (non-degradable) portion (mg C/L) k i Degradation rate constant of the degradable portion i (days -1 ) a Percentage of DOC fraction t a Contact time needed to degrade a certain fraction of DOC (days) Introduction According to the Brazilian National Sanitation System (SNIS), about 93% of the Brazilian population has access to potable water (SNIS 2014). However, the superficial and groundwater sources are subjected to potential pollution by natural and anthropogenic pollutants. Therefore, it is nec- essary to find new water sources and new treatment sys- tems or to improve the existing ones. Bank filtration (BF) & L. G. Romero-Esquivel lromero@itcr.ac.cr 1 Environmental Protection Research Centre (CIPA), School of Chemistry, Instituto Tecnolo ´gico de Costa Rica, 159-7050 Cartago, Costa Rica 2 Division of Water Sciences, University of Applied Sciences, Friedrich-List-Platz 1, 01069 Dresden, Germany 3 Department of Engineering and Environmental Technology, Federal University of Santa Maria, 98400-000 Frederico Westphalen, RS, Brazil 4 Department of Environmental and Sanitary Engineering, Federal University of Santa Catarina, 88040-900 Floriano ´polis, Brazil 123 Clean Techn Environ Policy DOI 10.1007/s10098-017-1382-5