Free nitrous acid promotes hydrogen production from dark fermentation of waste activated sludge

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Yali Wang
  • Jianwei Zhao
  • Dongbo Wang
  • Yiwen Liu
  • Qilin Wang
  • Bing-Jie Ni
  • Fei Chen
  • Qi Yang
  • Xiaoming Li
  • Guangming Zeng

Detail(s)

Original languageEnglish
Pages (from-to)113-124
Journal / PublicationWater Research
Volume145
Publication statusPublished - 15 Nov 2018
Externally publishedYes

Abstract

Simultaneous sludge fermentation and nitrite removal is an effective approach to enhance nutrient removal from low carbon-wastewater. It was found in this work that the presence of nitrite largely promoted hydrogen production from acidic fermentation of waste activated sludge (WAS). The results showed that with an increase of nitrite from 0 to 250 mg/L, the maximal hydrogen yield increased from 8.5 to 15.0 mL/g VSS at pH 5.5 fermentation and 8.1–13.0 mL/g VSS at pH 6 fermentation. However, the maximal hydrogen yield from WAS fermentation at pH 8 remained almost constant (2.9–3.7 mL/g VSS) when nitrite was in the range of 0–250 mg/L. Further analyses revealed that free nitrous acid (FNA) rather than nitrite was the major contributor to the promotion of hydrogen yield. The mechanism investigations showed that FNA not only accelerated the disruption of sludge cells but also promoted the biodegradability of organics released, thereby provided more biodegradable substrates for subsequent hydrogen production. Although FNA inhibited activities of all microbes involved in the anaerobic fermentation, its inhibitions to hydrogen consumers were much severer than those to hydrolytic microorganisms and hydrogen producers. Further investigations with microbial community showed that FNA increased the abundances of hydrogen producers (e.g., Citrobacter sp.) and denitrifiers (e.g., Dechloromonas sp.), but reduced the abundances of hydrogen consumers (e.g., Clostridium_aceticum). This work demonstrated for the first time that FNA in WAS fermentation systems enhanced hydrogen production. The findings obtained expand the application field of FNA and may provide supports for sustainable operation of wastewater treatment plants. © 2018 Elsevier Ltd

Research Area(s)

  • Anaerobic fermentation, Biohydrogen production, Free nitrous acid, Waste activated sludge

Bibliographic Note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to lbscholars@cityu.edu.hk.

Citation Format(s)

Free nitrous acid promotes hydrogen production from dark fermentation of waste activated sludge. / Wang, Yali; Zhao, Jianwei; Wang, Dongbo et al.
In: Water Research, Vol. 145, 15.11.2018, p. 113-124.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review