Anaerobic digestion with partial ozonation minimises greenhouse gas emission from sludge treatment and disposal

Hidenari Yasui, R. Matsuhashi, T. Noike, H. Harada

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


A novel anaerobic digestion process combined with partial ozonation on digested sludge was demonstrated for improving sludge digestion and biogas recovery by full-scale testing for 2 years and its performance was compared with a simultaneously operated conventional anaerobic digestion process. The novel process requires two essential modifications, which are ozonation for enhancing the biological degradability of sludge organics and concentrating of solids in the digester through a solid/liquid separation for extension of SRT. These modifications resulted in high VSS degradation efficiency of ca. 88%, as much as 1.3 times of methane production and more than 70% reduction in dewatered sludge cake production. Based on the performance, its energy demands and contribution for minimisation of greenhouse gas emission was evaluated throughout an entire study of sludge treatment and disposal schemes in a municipality for 130,000 p.e. The analysis indicated that the novel process with power generation from biogas would lead to minimal greenhouse gas emission because the extra energy production from the scheme was expected to cover all of the energy demand for the plant operation, and the remarkable reduction in dewatered sludge cake volumes makes it possible to reduce N2O discharge and consumption of fossil fuel in the subsequent sludge incineration processes.

Original languageEnglish
Pages (from-to)255-263
Number of pages9
JournalWater Science and Technology
Issue number3
Publication statusPublished - 2006 Apr 11


  • High-efficiency anaerobic digestion
  • Kyoto protocol
  • Sludge minimisation

ASJC Scopus subject areas

  • Environmental Engineering
  • Water Science and Technology


Dive into the research topics of 'Anaerobic digestion with partial ozonation minimises greenhouse gas emission from sludge treatment and disposal'. Together they form a unique fingerprint.

Cite this