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The effect of salinity on nitrite accumulation in a down‐flow hanging sponge reactor
Author(s) -
Natori T.,
Takemura Y.,
Harada H.,
Abe K.,
Ohashi A.,
Kimura M.,
Yamaguchi T.,
Okubo T.,
Uemura S.
Publication year - 2012
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.3770
Subject(s) - nitrite , nitrobacter , salinity , effluent , nitrospira , nitrification , chemistry , wastewater , nitrifying bacteria , oxidizing agent , environmental chemistry , bacteria , environmental engineering , biology , nitrogen , nitrate , ecology , environmental science , organic chemistry , genetics
BACKGROUND: In this study, the inductive effect of salinity on nitrite accumulation in a down‐flow hanging sponge (DHS) reactor, developed as a novel and cost‐effective wastewater treatment process, was evaluated by conducting a long‐term continuous experiment lasting more than 1400 days. RESULTS: The influent salinity was controlled by adding NaCl at concentrations ranging from 0 to 25 g Cl − L −1 . The effluent nitrite increased with increases in salinity, i.e. the fraction of nitrite to total nitrogen in the effluent increased from 1.6% at 0 g Cl − L −1 to 87.6% at 25 g Cl − L −1 . Fluorescence in situ hybridization (FISH) analysis revealed that as salinity increased, the nitrifying bacterial community in the DHS changed markedly at the species level. In particular, the dominant nitrite‐oxidizing bacteria changed from Nitrospira ‐sublineage I at 0 g Cl − L −1 to Nitrobacter spp. at 15 g Cl − L −1 . At 25 g Cl − L −1 , no nitrite‐oxidizing bacteria were detected. CONCLUSION: Our findings suggest that the DHS reactor is suitable for cost‐effective nitrite production processes and that salinity control using NaCl is an effective method for inducing nitrite accumulation. Copyright © 2012 Society of Chemical Industry