Respirometric assessment of primary sludge fermentation products

Cokgor E., ZENGIN G., TAS D., OKTAY S., RANDALL C., ORHON D.

JOURNAL OF ENVIRONMENTAL ENGINEERING, vol.132, no.1, pp.68-74, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 132 Issue: 1
  • Publication Date: 2006
  • Doi Number: 10.1061/(asce)0733-9372(2006)132:1(68)
  • Journal Name: JOURNAL OF ENVIRONMENTAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.68-74
  • Keywords: sludge, waste treatment, biodegradation, suspended solids, WASTE-WATER, ORGANIC-MATTER
  • Istanbul Technical University Affiliated: Yes

Abstract

This study investigates the potential of primary sludge fermentation for the generation of readily biodegradable substrate. Experimental evaluation indicates that uncontrolled fermentation converted 22% of the initial volatile suspended solids in the sludge into soluble biodegradable chemical oxygen demand (COD). More than 85% of the soluble COD generated was associated with the formation of short chain volatile fatty acids (VFAs). The recoverable fraction of the fermented sludge supernatant may potentially increase the biodegradable COD content of the primary effluent by 5%. The VFA composition predominantly involved acetic and propionic acids as reported in the literature. Due to the high VIA content, activated sludge Model No. 1 could not predict the COD fractionation in the primary sludge; activated sludge Model No. 3 provided a better interpretation of the oxygen uptake profile through initial storage of the VFAs in the sludge.