Biomass characterization of laboratory-scale thermophilic-mesophilic wastewater treatment processes

J. Suvilampi, A. Lehtomäki, J. Rintala

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)


Two thermophilic-mesophilic wastewater treatment processes, one as the combination of the thermophilic activated sludge process (ASP), followed by the mesophilic ASP and the other as thermophilic suspended carrier biofilm process (SCBP), followed by the mesophilic ASP, were used to study sludge characteristics and floc formation. Thermophilic bacteria in both ASP and SCBP were able to form flocs, which were <50 μm in size and had a weak structure and irregular shape. Flocs in both the mesophilic ASPs were larger in size (50-500 μm) and had more compact structures. Filamentous bacteria played an important role in both the thermophilic and mesophilic processes by forming bridges between small flocs. Both thermophilic processes showed a high density of dispersed particles, such as free bacteria. When hydraulic retention time (HRT) was decreased the biofilm was retained in the thermophilic SCBP better than the flocs in the thermophilic ASP. The mesophilic ASPs efficiently removed dispersed particles originating from the thermophilic processes.

Original languageEnglish
Pages (from-to)41-51
Number of pages11
JournalEnvironmental Technology
Issue number1
Publication statusPublished - Jan 2006
Externally publishedYes
Publication typeA1 Journal article-refereed


  • Aerobic
  • Filamentous bacteria
  • Floc size
  • Thermophilic
  • Wastewater

ASJC Scopus subject areas

  • General Environmental Science
  • Environmental Chemistry


Dive into the research topics of 'Biomass characterization of laboratory-scale thermophilic-mesophilic wastewater treatment processes'. Together they form a unique fingerprint.

Cite this