Managing the interactions between sulfate- and perchlorate-reducing bacteria when using hydrogen-fed biofilms to treat a groundwater with a high perchlorate concentration

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• 作者：Aura Ontiveros-Valencia^a ; ^b ; Youneng Tang^a ; ¹ ; Rosa Krajmalnik-Brown^a ; ^c ; ^{dr.rosy@asu.edu" class="auth_mail} ; Bruce E. Rittmann^a ; ^c ; ^{Rittmann@asu.edu" class="auth_mail}
• 关键词：Biofilm ; Hydrogen ; Perchlorate-reducing bacteria ; Sulfate-reducing bacteria ; qPCR ; Pyrosequencing
• 刊名：Water Research
• 出版年：15 May, 2014
• 年：2014
• 卷：55
• 期：Complete
• 页码：215-224
• 全文大小：1100 K

文摘

A groundwater containing an unusually high concentration (鈭?000聽渭g/L) of perchlorate (ClO₄^-) and significant (鈭?0聽mg/L) sulfate (SO₄^{2鈭?/sup>) was treated with hydrogen (H₂)-fed biofilms. The objective was to manage the interactions between sulfate-reducing bacteria (SRB) and perchlorate-reducing bacteria (PRB) by controlling the H₂-delivery capacity to achieve ClO₄- reduction to below the detection limit (4聽渭g/L). Complete ClO₄- reduction with minimized SO₄2鈭?/sup> reduction was achieved by using two membrane biofilm reactors (MBfRs) in series. The lead MBfR removed >96% ClO₄-, and the lag MBfR further reduced ClO₄- to below the detection limit. SO₄2鈭?/sup> reduction ranged from 10 to 60%, and lower SO₄2鈭?/sup> reduction corresponded to lower H₂ availability (i.e., lower H₂ pressure or membranes with lower H₂-delivery capacity). Minimizing SO₄2鈭?/sup> reduction improved ClO₄- removal by increasing the fraction of PRB in the biofilm. High SO₄2鈭?/sup> flux correlated with enrichment of Desulfovibrionales, autotrophic SRB that can compete strongly with denitrifying bacteria (DB) and PRB. Increased SO₄2鈭?/sup> reduction also led to enrichment of: 1) Ignavibacteriales and Thiobacteriales, sulfide-oxidizing bacteria that allow sulfur cycling in the biofilm; 2) Bacteroidales, heterotrophic microorganisms likely using organic sources of carbon (e.g., acetate); and 3) Spirochaetales, which potentially utilize soluble microbial products (SMPs) from autotrophic SRB to produce acetate.}