Life cycle assessment of integrated solid state anaerobic digestion and composting for on-farm organic residues treatment

Yangyang Li; Ashish Manandhar; Guoxue Li; Ajay Shah

doi:10.1016/j.wasman.2018.03.025

Life cycle assessment of integrated solid state anaerobic digestion and composting for on-farm organic residues treatment

Waste Manag. 2018 Jun:76:294-305. doi: 10.1016/j.wasman.2018.03.025. Epub 2018 Mar 20.

Authors

Yangyang Li¹, Ashish Manandhar², Guoxue Li³, Ajay Shah⁴

Affiliations

¹ Department of Food, Agricultural and Biological Engineering, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA; College of Resource and Environmental Science, China Agricultural University, Beijing 100193, PR China; Beijing Key Laboratory of Farmland Pollution Prevention-control and Remediation, Beijing 100193, PR China.
² Department of Food, Agricultural and Biological Engineering, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA.
³ College of Resource and Environmental Science, China Agricultural University, Beijing 100193, PR China; Beijing Key Laboratory of Farmland Pollution Prevention-control and Remediation, Beijing 100193, PR China.
⁴ Department of Food, Agricultural and Biological Engineering, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA. Electronic address: shah.971@osu.edu.

PMID: 29571569
DOI: 10.1016/j.wasman.2018.03.025

Abstract

Driven by the gradual changes in the structure of energy consumption and improvements of living standards in China, the volume of on-farm organic solid waste is increasing. If untreated, these unutilized on-farm organic solid wastes can cause environmental problems. This paper presents the results of a life cycle assessment to compare the environmental impacts of different on-farm organic waste (which includes dairy manure, corn stover and tomato residue) treatment strategies, including anaerobic digestion (AD), composting, and AD followed by composting. The input life cycle inventory data are specific to China. The potential environmental impacts of different waste management strategies were assessed based on their acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), ecotoxicity potential (ETP), and resource depletion (RD). The results show that the preferred treatment strategy for dairy manure is the one that integrated corn stover and tomato residue utilization and solid state AD technologies into the system. The GWP of integrated solid state AD and composting was the least, which is -2900 kg CO₂ eq/ t of dairy manure and approximately 14.8 times less than that of current status (i.e., liquid AD of dairy manure). Solid state AD of dairy manure, corn stover and tomato residues is the most favorable option in terms of AP, EP and ETP, which are more than 40% lower than that of the current status (i.e., AP: 3.11 kg SO₂, EP: -0.94 kg N, and ETP: -881 CTUe (Comparative Toxic Units ecotoxicity)). The results also show that there is a significant potential for AP, EP, ETP, and GWP reduction, if AD is used prior to composting. The scenario analysis for transportation distance showed that locating the AD plant and composting facility on the farm was advantageous in terms of all the life cycle impact categories.

Keywords: Composting; Environmental emissions; On-farm organic waste treatment; Solid-state anaerobic digestion.

MeSH terms

China
Composting*
Farms*
Manure
Waste Management

Substances

Manure