Increasing the performance of anaerobic digestion: Pilot scale experimental study for thermal hydrolysis of mixed sludge

  • S.I. Perez-ElviraEmail author
  • M. Fdz-Polanco
  • F. Fdz-Polanco
Research Article


The performance of a pilot plant operation combining thermal hydrolysis (170°C, 30 min) and anaerobic digestion (AD) was studied, determining the main properties for samples of fresh mixed sludge, hydrolyzed sludge, and digested sludge, in order to quantify the thermal pretreatment performance (disintegration, solubilisation, and dewaterability) and its impact on the anaerobic digestion performance (biodegradability, volatile solids reduction, and digester rheology) and end product characteristics (dewaterability, sanitation, organic and nitrogen content). The disintegration achieved during the thermal treatment enhances the sludge centrifugation, allowing a 70% higher total solids concentration in the feed to anaerobic digestion. The digestion of this sludge generates 40% more biogas in half the time, due to the higher solids removal compared to a conventional digester. The waste generated can be dewatered by centrifugation to 7% dry solids without polymer addition, and is pathogen free.


anaerobic digestion (AD) biogas performance sludge thermal hydrolysis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Shimizu T, Kudo K, Nasu Y. Anaerobic waste—activated sludge digestion—a bioconversion mechanism and kinetic model. Biotechnology and Bioengineering, 1993, 41(11): 1082–1091CrossRefGoogle Scholar
  2. 2.
    Li Y Y, Noike T. Upgrading of anaerobic digestion of waste activated sludge by thermal pretreatment. Water Science and Technology, 1992, 26: 857–864Google Scholar
  3. 3.
    Chiu Y C, Chang C N, Lin L G, Huang S J. Alkaline and ultrasonic pre-treatment of sludge before anaerobic digestion. Water Science and Technology, 1997, 36(11): 155–162CrossRefGoogle Scholar
  4. 4.
    Dohányos M, Zabranska J, Jenicek P. Enhancement of sludge anaerobic digestion by using of a special thickening centrifuge. Water Science and Technology, 1997, 36(11): 145–153CrossRefGoogle Scholar
  5. 5.
    Kepp U, Machenbach I, Weisz N, Solheim O E. Enhanced stabilisation of sewage sludge through thermal hydrolysis–3 years of experience with full scale plants. Water Science and Technology, 1999, 42(9): 89–96Google Scholar
  6. 6.
    Mukherjee R S, Levine A D. Chemical solubilization of particulate organics as a pretreatment approach. Water Science and Technology, 1992, 26(9–11): 2289–2292Google Scholar
  7. 7.
    Pérez-Elvira S I, Nieto-Diez P, Fdz-Polanco F. Sludge minimization technologies. Rev. Environmental Science and Biotechnology, 2006, 5(4): 375–398CrossRefGoogle Scholar
  8. 8.
    Weemaes M, Verstraete W H. Evaluation of current wet sludge disintegration techniques. Journal of Chemical Technology and Biotechnology (Oxford, Oxfordshire), 1998, 73(2): 83–92CrossRefGoogle Scholar
  9. 9.
    Fdz-Polanco F, Velázquez R, Pérez-Elvira S I, Casas C, del Barrio D, Cantero F J, Fdz-Polanco M, Rodríguez P, Panizo L, Serrat J, Rouge P. Continuous thermal hydrolysis and energy integration in sludge anaerobic digestion plants. Water Science and Technology, 2008, 57(8): 1221–1226CrossRefGoogle Scholar
  10. 10.
    Kepp U, Solheim O E. Meeting increased demands on sludge quality—experience with full scale plant for thermal disintegration. Proceedings of the 9th World Congress, Anaerobic Conversion for Sustainability, 2001Google Scholar
  11. 11.
    APHA. AWWA, WPCF. Standard Methods for the examination of Water and Wastewater, 21th ed. Washington DC: American Public Health Association, 2005Google Scholar
  12. 12.
    Fdz-Polanco F, Nieto P, Pérez Elvira S I, van der Zee F P, Fdz-Polanc M, García P A. Automated equipment for anaerobic sludge parameters determination. Water Science and Technology, 2005, 52(1–2): 479–485Google Scholar

Copyright information

© Higher Education Press and Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • S.I. Perez-Elvira
    • 1
    Email author
  • M. Fdz-Polanco
    • 1
  • F. Fdz-Polanco
    • 1
  1. 1.Department of Chemical Engineering and Environmental TechnologyUniversity of ValladolidValladolidSpain

Personalised recommendations