Life Cycle Assessment on Food Waste Management and Recycling

Yasuhiro Hirai*, Masaki Murata**, Shin-ichi Sakai*** and Hiroshi Takatsuki*
* Environment Preservation Center, Kyoto University
** Japan Quality Assurance Organization
*** National Institute for Environmental Studies
+ Correspondence should be addressed to Yasuhiro Hirai:
(Yoshida-honbachi, Sakyo-ku, Kyoto 606-8501 Japan)

Abstract
A case study of food waste treatment was conducted to compare the impacts of four scenarios: incineration, incineration after biogasification, biogasification followed by composting, and composting. Potential contributions to climate change, acidification, consumption of landfill and human toxicity were assessed. Characterization of human toxicity caused by heavy metals and dioxins was performed by three multimedia fate models. Scenarios incorporating the biogasification process showed lower impact on climate change and human toxicity. Compared to incineration, composting causes larger emission of green house gases (GHGs), but its lower consumption of landfill more than compensates for the GHGs emission. The ranking of the four scenarios on human toxicity varied depending on the characterization models applied. The steady state models placed high priority on emission of heavy metals in farmland, whereas the dynamic model (time horizon 100 years) estimated the emission of dioxins from the incineration process as more significant.

Key words: LCA, composting, biogasification, dioxins, heavy metals