Monitoring biofilm function in new and matured full-scale slow sand filters using flow cytometric histogram image comparison (CHIC)

WATER RESEARCH

卷:138

Article

Chan, Sandy^1,2,3  Pullerits, Kristjan^1,2,3  Riechelmann, Janine¹  Persson, Kenneth M.^2,3,4  Radstrom, Peter¹  Paul, Catherine J.^1,4 

[1] Lund Univ, Dept Chem, Appl Microbiol, POB 124, SE-22100 Lund, Sweden

[2] Sweden Water Res AB, Ideon Sci Pk,Scheelevagen 15, SE-22370 Lund, Sweden

[3] Sydvatten AB, Hyllie Stn Storg 21, SE-21532 Malmo, Sweden

[4] Lund Univ, Dept Bldg & Environm Technol, Water Resources Engn, POB 118, SE-22100 Lund, Sweden

关键词: Slow sand filters;    Drinking water;    Flow cytometry;    Schmutzdecke;    Cytometric histogram image comparison (CHIC);    Biofilm;   

DOI  :  10.1016/j.watres.2018.03.032

来源: Elsevier

【 摘 要 】

While slow sand filters (SSFs) have produced drinking water for more than a hundred years, understanding of their associated microbial communities is limited. In this study, bacteria in influent and effluent water from full-scale SSFs were explored using flow cytometry (FCM) with cytometric histogram image comparison (CHIC) analysis; and routine microbial counts for heterotrophs, total coliforms and Escherichia coli. To assess if FCM can monitor biofilm function, SSFs differing in age and sand composition were compared. FCM profiles from two established filters were indistinguishable. To examine biofilm in the deep sand bed, SSFs were monitored during a scraping event, when the top layer of sand and the schmutzdecke are removed to restore flow through the filter. The performance of an established SSF was stable: total organic carbon (TOC), pH, numbers of heterotrophs, coliforms, E. coli, and FCM bacterial profile were unaffected by scraping. However, the performance of two newly-built SSFs containing new and mixed sand was compromised: breakthrough of both microbial indicators and TOC occurred following scraping. The compromised performance of the new SSFs was reflected in distinct effluent bacterial communities; and, the presence of microbial indicators correlated to influent bacterial communities. This demonstrated that FCM can monitor SSF performance. Removal of the top layer of sand did not alter the effluent water from the established SSF, but did affect that of the SSFs containing new sand. This suggests that the impact of the surface biofilm on effluent water is greater when the deep sand bed biofilm is not established. (C) 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.Org/licenses/by-nc-nd/4.0/).

【 授权许可】

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