Dynamics of the physiochemical and community structures of biofilms under the influence of algal organic matter and humic substances

WATER RESEARCH

卷:158

Article

Li, Lei¹  Jeon, Youchul¹  Lee, Sang-Hoon¹  Ryu, Hodon²  Santo Domingo, Jorge W.²  Seo, Youngwoo^1,3 

[1] Univ Toledo, Dept Civil & Environm Engn, Mail Stop 307,3048 Nitschke Hall, Toledo, OH USA

[2] US EPA, Water Syst Div, Natl Risk Management Res Lab, Cincinnati, OH 45268 USA

[3] Univ Toledo, Dept Chem Engn, Mail Stop 307,3048 Nitschke Hall, Toledo, OH 43606 USA

关键词: Algal organic matter;    Humic substance;    Biofilm development;    Physiochemical and community structure;    Drinking water;   

DOI  :  10.1016/j.watres.2019.04.014

来源: Elsevier

【 摘 要 】

Increased loading of algal organic matter (AOM) during harmful algal blooms not only burdens water treatment processes but also challenges safe drinking water delivery. While organic constituents promote biofilm growth in drinking water distribution systems (DWDS), the effects of AOM on biofilm formation in DWDS are not well understood. Herein, three parallel biofilm reactors were used to assess and compare how treated AOM- and humic substance (HS)-impacted bulk water, and R2A medium (a control) affect biofilm development for 168 days. The 16S rRNA gene sequencing analysis revealed that the bacterial communities in biofilms were clustered with the organic matter types in bulk water, where Family Comamonadaceae was the most dominant but showed different temporal dynamics depending on the organic matter characteristics in bulk water. Higher diversity was observed in the biofilms grown in AOM-impacted bulk water (BFAOM) than biofilms grown in HS -impacted (BFHS) and R2A-impacted bulk water (BFR2A) as the biofilms matured. In addition, some taxa (e.g., Rhodobacteraceae and Sphingomonadaceae) were enriched in BFAOM compared to BFHS and BFR2A. The biofilm image analysis results indicated that compared to BFHS, BFAOM and BFR2A had relatively thinner and heterogeneous physical structures with lower amounts of cell biomass, extracellular polymeric substances (EPS), and higher EPS protein/polysaccharide ratios. Overall, this study revealed how AOM- and HS-impacted bulk water shape the physiochemical and community structures of biofilms, which can provide insights into assessing biofilm-associated risks and optimizing disinfection practices for biofilm control in DWDS. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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