African Journal of
Environmental Science and Technology

  • Abbreviation: Afr. J. Environ. Sci. Technol.
  • Language: English
  • ISSN: 1996-0786
  • DOI: 10.5897/AJEST
  • Start Year: 2007
  • Published Articles: 1042

Full Length Research Paper

Food waste produced lactic acid for pathogen inactivation, urea stabilization and odor control in feces

Zerihun Getaneh
  • Zerihun Getaneh
  • School of Civil and Environmental Engineering, Addis Ababa Institute of Technology, Addis Ababa University, Ethiopia.
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Agizew Nigussie
  • Agizew Nigussie
  • School of Civil and Environmental Engineering, Addis Ababa Institute of Technology, Addis Ababa University, Ethiopia.
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Adey Desta
  • Adey Desta
  • Institute of Biotechnology, College of Natural and Computational Sciences, Addis Ababa University, Ethiopia.
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Nancy G. Love
  • Nancy G. Love
  • Department of Civil and Environmental Engineering, University of Michigan, USA.
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  •  Received: 30 July 2021
  •  Accepted: 14 September 2021
  •  Published: 31 October 2021

Abstract

Source separated human feces can be used as a valuable source of nutrients if it is properly sanitized and its nutrient is conserved. In this study, the efficiency of fresh cabbage waste produced lactic acid treatment of human feces as a pretreatment to evaluate the sanitizing effect, urea stabilizing, and odor removal was investigated for 33 days. Four reactors were used for the treatment process containing different lactic acid to feces ratio (that is, 1:1, 1:2, 1:3 and control). Escherichia coli was used as the indicator of pathogen inactivation, whereas pH and ammonium were used as the main indicators of urea hydrolysis. The result showed that inactivation of the indicator, stabilization of urea and odor reduction improved in 1:1 reactor compared with other treatment reactors. Therefore, human feces is recommended to be treated by food waste produced lactic acid for 9 days for hygienic and stabilization purpose. Under this treatment condition, pH is maintained below 4.1 and ammonium content is maintained at approximately 5.0 mg/g. Moreover, the combination of lactic acid and activated biochar also played important role in odor control for effective treatment of feces.

 

Key words: Activated biochar, feces, lactic acid, Escherichia coli, urea stabilization.