Nitrite-dependent microbial utilization for simultaneous removal of sulfide and methane in sewers
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Author(s)
Type
Journal Article
Abstract
Chemicals are commonly dosed in sewer systems to reduce the emission of hydrogen sulfide (H2S) and methane (CH4), incurring high costs and environmental concerns. Nitrite dosing is a promising approach as nitrite can be produced from urine wastewater, which is a feasible integrated water management strategy. However, nitrite dosing usually requires strict conditions, e.g., relatively high nitrite concentration (e.g., ∼200 mg N/L) and acidic environment, to inhibit microorganisms. In contrast to “microbial inhibition”, this study proposes “microbial utilization” concept, i.e., utilizing nitrite as a substrate for H2S and CH4 consumption in sewer. In a laboratory-scale sewer reactor, nitrite at a relatively low concentrations of 25–48 mg N/L was continuously dosed. Two nitrite-dependent microbial utilization processes, i.e., nitrite-dependent anaerobic methane oxidation (n-DAMO) and microbial sulfide oxidation, successfully occurred in conjunction with nitrite reduction. The occurrence of both processes achieved a 58 % reduction in dissolved methane and over 90 % sulfide removal in the sewer reactor, with microbial activities measured as 15.6 mg CH4/(L·h) and 29.4 mg S/(L·h), respectively. High copy numbers of n-DAMO bacteria and sulfide-oxidizing bacteria (SOB) were detected in both sewer biofilms and sediments. Mechanism analysis confirmed that the dosed nitrite at a relatively low level did not cause the inhibition of sulfidogenic process due to the downward migration of activity zones in sewer sediments. Therefore, the proposed “microbial utilization” concept offers a new alternative for simultaneous removal of sulfide and methane in sewers.
Date Issued
2024-09-01
Online Publication Date
2024-07-17T15:47:10Z
Date Acceptance
2024-06-29
ISSN
2589-9147
Publisher
Elsevier
Journal / Book Title
Water Research X
Volume
24
Copyright Statement
© 2024 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/bync/4.0/).
Identifier
http://dx.doi.org/10.1016/j.wroa.2024.100231
Publication Status
Published
Article Number
100231
Date Publish Online
2024-06-30