Assessing the changes in E. coli levels and nutrient dynamics during vermicomposting of food waste under lab and field scale conditions.
Vermicomposting (VC) has proven to be a promising method for treating garden, household, and municipal wastes. Although the VC has been used extensively for converting wastes into fertilizers, pathogens such as Escherichia coli (E. coli) survival during this process is not well documented. In this study, both lab and field scale experiments were conducted assessing the impacts of earthworms in reducing E. coli concentration during VC of food waste. In addition, other pertinent parameters such as temperature, carbon and nitrogen content, moisture content, pH, volatile solids, micronutrients (P, K, Ca, Mg, and S), and heavy metals (Zn, Mn, Fe, and Cu) were monitored during the study. The lab and field scale experiments were conducted for 107 and 103 days, respectively. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study. Results showed that VC was not significantly effective in reducing E. coli levels in food waste under both lab and field scale settings. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study.
Department of Population Health and Reproduction, University of California Davis, Davis, CA, 95616, USA.|Department of Biological and Agricultural Engineering, University of California Davis, Davis, CA, 95616, USA.
Wenlong
W
Cao
Department of Population Health and Reproduction, University of California Davis, Davis, CA, 95616, USA.
Venkata
V
Vaddella
Department of Population Health and Reproduction, University of California Davis, Davis, CA, 95616, USA.
Sagor
S
Biswas
Department of Agroecology and Sustainable Agriculture, University of California Davis, Davis, CA, 95616, USA.
Katherine
K
Perkins
Department of Evolution and Ecology, University of California Davis, Davis, CA, 95616, USA.
Cameron
C
Clay
Department of Pharmaceutical Chemistry, University of California Davis, California, 95616, USA.
Tong
T
Wu
Department of Biochemistry and Molecular Biology, University of California Davis, California, 95616, USA.
Yawen
Y
Zheng
Department of Biological System Engineering, Washington State University, Pullman, Washington, 99164, USA.
Pius
P
Ndegwa
Department of Population Health and Reproduction, University of California Davis, Davis, CA, 95616, USA. pkpandey@ucdavis.edu.
Pramod
P
Pandey
D000818:Animals; D002244:Carbon / Q000032:analysis / Q000378:metabolism; D004926:Escherichia coli; D005502:Food; D019216:Metals, Heavy / Q000032:analysis; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D009835:Oligochaeta; D012037:Refuse Disposal / Q000379:methods; D012987:Soil / Q000737:chemistry; D064091:Waste Disposal Facilities
D019216:Metals, Heavy; D012987:Soil; D002244:Carbon; D009584:Nitrogen
C/N ratio; E. coli; Eisenia fetida; Food waste; Vermicomposting