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Free Nitrous Acid (FNA)-Based Pretreatment Enhances Methane Production from Waste Activated Sludge

Journal Article


Abstract


  • Anaerobic digestion of waste activated sludge (WAS) is currently enjoying renewed interest due to the potential for methane production. However, methane production is often limited by the slowhydrolysis rate and/or poor methane potential of WAS. This study presents a novel pretreatment strategy based on free nitrous acid(FNA or HNO2) to enhance methane production from WAS.Pretreatment of WAS for 24 h at FNA concentrations up to 2.13mg N/L substantially enhanced WAS solubilization, with the highestsolubilization (0.16 mg chemical oxygen demand (COD)/mg volatilesolids (VS), at 2.13 mg HNO2−N/L) being six times that withoutFNA pretreatment (0.025 mg COD/mg VS, at 0 mg HNO2−N/L).Biochemical methane potential tests demonstrated methane produc-tion increased with increased FNA concentration used in the pretreatment step. Model-based analysis indicated FNApretreatment improved both hydrolysis rate and methane potential, with the highest improvement being approximately 50%(from 0.16 to 0.25 d−1) and 27% (from 201 to 255 L CH4/kg VS added), respectively, achieved at 1.78−2.13 mg HNO2−N/L.Further analysis indicated that increased hydrolysis rate and methane potential were related to an increase in rapidly biodegradable substrates, which increased with increased FNA dose, while the slowly biodegradable substrates remained relatively static

UOW Authors


  •   Wang, Qilin (external author)
  •   Ye, Liu (external author)
  •   Jiang, Guangming
  •   Jensen, Paul (external author)
  •   Batstone, Damien J. (external author)
  •   Yuan, Zhiguo (external author)

Publication Date


  • 2013

Citation


  • Wang, Q., Ye, L., Jiang, G., Jensen, P. D., Batstone, D. J. & Yuan, Z. (2013). Free Nitrous Acid (FNA)-Based Pretreatment Enhances Methane Production from Waste Activated Sludge. Environmental Science and Technology, 47 11897-11904.

Scopus Eid


  • 2-s2.0-84886930465

Number Of Pages


  • 7

Start Page


  • 11897

End Page


  • 11904

Volume


  • 47

Place Of Publication


  • United States

Abstract


  • Anaerobic digestion of waste activated sludge (WAS) is currently enjoying renewed interest due to the potential for methane production. However, methane production is often limited by the slowhydrolysis rate and/or poor methane potential of WAS. This study presents a novel pretreatment strategy based on free nitrous acid(FNA or HNO2) to enhance methane production from WAS.Pretreatment of WAS for 24 h at FNA concentrations up to 2.13mg N/L substantially enhanced WAS solubilization, with the highestsolubilization (0.16 mg chemical oxygen demand (COD)/mg volatilesolids (VS), at 2.13 mg HNO2−N/L) being six times that withoutFNA pretreatment (0.025 mg COD/mg VS, at 0 mg HNO2−N/L).Biochemical methane potential tests demonstrated methane produc-tion increased with increased FNA concentration used in the pretreatment step. Model-based analysis indicated FNApretreatment improved both hydrolysis rate and methane potential, with the highest improvement being approximately 50%(from 0.16 to 0.25 d−1) and 27% (from 201 to 255 L CH4/kg VS added), respectively, achieved at 1.78−2.13 mg HNO2−N/L.Further analysis indicated that increased hydrolysis rate and methane potential were related to an increase in rapidly biodegradable substrates, which increased with increased FNA dose, while the slowly biodegradable substrates remained relatively static

UOW Authors


  •   Wang, Qilin (external author)
  •   Ye, Liu (external author)
  •   Jiang, Guangming
  •   Jensen, Paul (external author)
  •   Batstone, Damien J. (external author)
  •   Yuan, Zhiguo (external author)

Publication Date


  • 2013

Citation


  • Wang, Q., Ye, L., Jiang, G., Jensen, P. D., Batstone, D. J. & Yuan, Z. (2013). Free Nitrous Acid (FNA)-Based Pretreatment Enhances Methane Production from Waste Activated Sludge. Environmental Science and Technology, 47 11897-11904.

Scopus Eid


  • 2-s2.0-84886930465

Number Of Pages


  • 7

Start Page


  • 11897

End Page


  • 11904

Volume


  • 47

Place Of Publication


  • United States