Semi-continuous production of volatile fatty acids from citrus waste using membrane bioreactors

Lukitawesa L., Eryildiz B., Mahboubi A., Millati R., Taherzadeh M. J.

INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES, vol.67, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 67
  • Publication Date: 2021
  • Doi Number: 10.1016/j.ifset.2020.102545
  • Journal Name: INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Biotechnology Research Abstracts, CAB Abstracts, Compendex, Food Science & Technology Abstracts, Veterinary Science Database
  • Istanbul Technical University Affiliated: Yes

Abstract

In the production of volatile fatty acids (VFAs) from citrus waste, organic loadings rates (OLR) from 1 to 8 g VS/ L?d were applied in semi-continuous anaerobic fermentation using a tubular membrane bioreactor (MBR). Filtration fluxes of the membrane were in the range of 7.9?8.5 L/m2?h. trans-Membrane pressure (TMP) revolved around 24.1?67.5 mbar. No obvious fouling and clogging occurred. The highest yield of VFAs 0.67 g VFA/g VS (volatile solids) was achieved at OLR 4 g VS/L?d. When citrus waste was pretreated to remove D-limonene using an airlift reactor, the highest yield of VFAs 0.84 g VFA/g VS was also obtained at OLR 4 g VS/L?d. A further increase in OLR of up to 8 g VS/L?d caused a sharp decrease in yield for the untreated citrus waste and only marginal changes were observed for the pretreated citrus waste. The main composition of VFAs was acetate, butyrate, caproate, and propionate.